Pollinators

Pine Barrens, plants and their pollinators

2012-01-28T14:12:00.000-08:00

A few plants of the New Jersey Pine Barrens and their pollinators

The most predominant tree and the one that gives the name to the place is the pine tree, especially the pitch pine (Pinus rigida). It uses the wind for pollen transport. This ancient method of pollination existed long before there were any flowering plants or any pollen carriers. The features that make wind pollination possible are: the production of vast amounts of pollen and the relative proximity of plants to each other.

Some members of the flowering plants group have reverted to the time honored tradition of wind pollination; they do just fine without the help of pollinators. Such are oaks, birches, most maples, grasses and sedges, among others. Notice that such plants grow fairly close to each other and produce abundant pollen.

Plants that use pollinators possess flowers to attract and recompense the visitors. This investment is compensated by the reduced need to produce large amounts of pollen. The array of different adaptations is impressive. Here are some found in the Pine Barrens.

Sweetbay Magnolia (Magnolia virginiana). Magnolias are among the oldest flowering plants. Their ancestors resorted to the only available pollinators at that time, rather clumsy ones, such as beetles. Beetles mouth parts are good for biting and chewing, not for delicately gathering pollen and nectar. They chew on the flowers along with feeding on some pollen and can make a big mess. Magnolias continue to be pollinated mostly by beetles and they tend to have rather tough, leathery petals to protect themselves against such insults.

Wild cherry (Prunus serotina). The shape of its flowers is relatively simple and open, its pollen and nectar are easy to reach, thus a large number of species of bees and even other insects visit these flowers. Some of these flies mimic bees very skillfully and manage to fool not only hungry birds but even some human observers.

Mountain laurel in bloom

Mountain laurel (Kalmia latifolia). This attractive flower has a very peculiar shape. The anthers (the part of the flower that carries the pollen) remain caught inside little pockets made by the petals; their stalks or filaments remain taut and ready to snap. When an insect lands on the flower they spring to action. Each anther comes out of the pocket and gives the insect a good dusting of pollen.

Blueberries, cranberries (Vaccinium corymbosum, Vaccinium macrocarpon and others). The anthers of these flowers are shaped very differently from those of most other flowers. They don’t split open exposing the pollen; instead they have an opening at the end of the anther. The way to get the pollen out requires some skillful work by the pollinator. It has to hang on to the flower and give it a good shake; the way you shake a salt shaker. Some bumblebees and many other native bees are very adept at this task. The blueberry bee (Habropoda laboriosa), can pollinate so many flowers in her short adult life of a few weeks that her labor can result on $20 worth of blueberries, probably more at today’s prices. Honey bees, on the other hand, never learned how to perform this task. They do visit blueberries and cranberries and accomplish some pollination although not as efficiently as the native bees and bumblebees. However, large blueberry and cranberry operations resort to honey bees because of the convenience of placing hives on the fields and because such large tracts of land fail to provide nesting places for native bees. Pollinating these berries is stressful for honey bees; they are not well adapted to such diet and suffer as a consequence. Wild grown berries, on the other hand, get all their needed pollination from native bees.

Lady slipper (Cypripedium acaule). The lovely lady slipper can play unpleasant tricks on pollinators; its elaborate shape is nothing but a seductive trap with a complicated escape route. The flower yields an aroma that some bees find irresistible. When they reach the flower, they perch at the edge of the sac and frequently slip and fall. Soon they found that they can’t get out the way they came in because the inside walls are very slippery and the lip of the sac curves inwards making it even harder. Fortunately the orchid has provided a ladder at the back of the flower and a very narrow passage that leads back to freedom. The bee that struggles through this tunnel gets a sac of pollen, called pollinia, stuck to its back. It will remember the unfortunate experience long enough to move away from that patch, but shortly after it will be quite willing to repeat the experience because its little brain will have forgotten all about it.

Inch worms: more little known pollinators

2012-01-09T12:53:00.000-08:00

Inchworm (Eupithecia) on coneflower

Another group of not well known pollinator moths are the members of the Geometrid family, better known as inch-worms. The name refers to the peculiar way their caterpillars move around inch by inch like measuring the distance they traverse. The scientific name also refers to the caterpillars. Some of these caterpillars can be found on flowers, but of course, they are not likely to do any pollination, since they don't move very far when feeding on the nutritious flowers.

Inchworm (Alsophila pometaria) showing its characteristic gait

This is a family that, unlike the previous ones has a good number of pollinators, both diurnal and nocturnal. The ones that fly at night are usually collected by attracting them to lights and, unfortunately, there is very little research about their flower visiting activities. A little more is known about the role as pollinators of the ones that visit flowers during the day; but not much.

Chickweed Geometer (Haematopis grataria)

Day fliers can be colorful, in contrast to night fliers. The chickweed geometer and the white-striped black moths fall somewhere in the middle between colorful and drab. But the white tipped black moth could compete with many butterflies with its orange body and dark blue wings with white tips.

The only thing that we can say for certain about geometrid moths is that many of them visit flowers regularly and probably accomplish some pollination.

Family Geometridae

List of articles

More little known moth pollinators: seed casebearers and flower moths

2011-12-22T14:41:00.000-08:00

Seed case bearer moth Coleophora trifolii

It continues to amaze me how little we know about pollinator moths, aside from a handful of the more familiar ones. I will be covering a couple of families, somewhat related (they are members of the superfamily Gelechioidea) which is part of a larger and loosely defined group called microlepidoptera. The main thing microlepidoptera have in common is their small size, but many may not be related.

The two families I mention here may or may not be pollinators; all we can say for certain is that they visit flowers. It would be nice to know more.

Among the casebearer moths there is a handful of species known as seed casebearers. As the name suggests, the caterpillars carry a case which serves as refuge. The seed casebearers feed on seeds, rather than other parts of the plants. The adults are silvery, with long antennae. When the wings are folded they are long and narrow, like little cigars. They can be seen at flowers of the daisy family. Not much else is known about their activities.

The other flower visitors in this group of moths belong to a family with a difficult scientific name, Xyloryctidae. Fortunately the common name is nicer and self explanatory: flower moths. They look very similar to the members of the previous group. They are small and hold their wings in a similar position. These moths fly during the day and are often seen nectaring at flowers. In this case, we can be a little more certain of their function as pollinators.

List of articles

Metalmark moths. More little known pollinators

2011-12-18T16:46:00.000-08:00

Anthophila fabriciana. By Remo Angelini

So much to learn about pollinators! Huge numbers of moths, flies and beetles don't get enough credit for their jobs; the better known ones, bees and butterflies, get all the glory. So let us take a look at a little known moth or family of moths, the Choreutidae, better known as metalmark moths, not to be confused with metalmarks, which are butterflies. Both the butterflies and the moths get their names for the metallic iridescence of their wings.

They are small, no bigger than 10 mm (say, the size of your small fingernail); members of a larger group of moths often called micromoths. The wings are broad and square-tipped; this gives them a chunky appearance. The patches of metallic colors on their wings can be very colorful.

Saptha divitiosa by Bettaman

Metalmark moths fly during the day and can be seen often at flowers. They drink nectar with their long tongues, just as many other moths and butterflies do. Not much is know about their role as pollinators, but we can be almost certain that they perform this function for some flowers, considering their habits.

More is known about the mimicry that many of them perform with their peculiar appearance. The pattern of their wings resembles a jumping spider. They also move in a way that adds to the deception. This disguise serves them well; jumping spiders ordinarily prey on them, but sometimes are deceived to the point to behave as if they were facing a member of their own species. I have no pictures to put here, but you can see a spider mimic.

A few members of the family, called brenthia, strut around like peacocks, so naturally they are called peacock brenthia.

It would be nice to learn more about metal mark moths' role as pollinators. If anyone reading this knows more or has had the opportunity to see one of these moths in action, please, let me know. I will strive to find and photograph some of them next season.

List of articles

Black-and-yellow lichen moth, a little known pollinator

2011-12-02T17:05:00.000-08:00

We are very familiar with the pollinating role of butterflies and we are aware that a number of moths, such as the hummingbird moth also visit flowers frequently and provide pollinating services. But we seldom pay attention to the countless other flower-visiting moths and their roles as pollinators.

Lycomorpha pholus (Black-and-yellow Lichen Moth), a very likely pollinator

The black-and-yellow lichen moth is a very attractive, rather slender moth often seen visiting goldenrods and some other flat, open flowers. It is widely distributed throughout the continent, from Canada to Texas and Mexico. Adults fly from June to September. The larva may take longer than a year to complete its development.

Its wings are black and yellow or black and orange as its name indicates. The body and legs are black or blue-black. The caterpillar of this moth and a number of its relatives feed on lichens; that is what the other part of the name refers to. It resembles the lichens it feeds on in color and appearance; a convenient disguise that hides it from predators.

The adult performs another interesting trick of mimicry. It bears an astonishing resemblance to some beetles, called net-winged beetles, especially the end band net-wing or Calopteron terminale. These beetles are poisonous and are avoided by hungry birds. The contrasting colors serve as advertisement of their bad taste. The black-and-yellow lichen moth is also poisonous and so is the orange-patched smoky moth, another one with a similar pattern. The resemblance seems to be beneficial to all of them. Birds need to learn only one kind of warning signal to avoid all these unrelated species and so more beetles and moths survive than if they exhibited different alarm signals. This is called Mullerian mimicry in honor of Muller, the first one to describe and explain this phenomenon.

Calopteron terminale (End Band Net-wing), a poisonous lycid beetle

Orange-patched Smoky Moth, a member of the mimicry complex

Little is known about the black-and-yellow lichen moth's role as a pollinator; but given its flower-visiting habits it is almost certain that it performs this function. This is just another example of how much we need to learn about moths and their role in the ecosystems. If anybody reading this knows of some information on the subject, please, point me in the right direction. We all need to learn more about this and many other moths' capacity as pollinators.

Another view of the black-and-yellow Lichen Moth

See: Bugguide.net

List of articles

Pollinators, the night shift

2011-11-23T14:53:00.000-08:00

We are familiar with day-blooming flowers and day-visiting insects: bees, butterflies, flies and a few others. These insects prefer nice, warm, sunny days to pay visits to flowers. In fact, their muscles need a certain critical temperature to begin functioning. Sometimes you can see some of them sitting still during chilly mornings, waiting for the sun to warm them up sufficiently so they can take to the air.

Nocturnal moths are another story; some are well adapted to colder temperatures; they also have a good sense of smell and eyes that allow them to flight at night. Their favorite flowers are to be visited at night. They open their white or cream colored corollas after the sun sets, sending their strong scent to the air and producing abundant nectar at the same time. The moths, well attuned to their cues, avidly seek the sweet recompense.

When the day-pollinators complete their 9-5 schedule, the night shift takes over. Most prefer to work at dawn or dusk and they are called crepuscular pollinators. Only a few venture in the dead of night. You may be fortunate enough to have some nocturnal visitors to your garden, if you have moonflowers, evening primroses, nicotiana or morning glories. It can be quite a treat to see hawk moths in a regular basis visiting your garden; some show up almost daily at an appointed time. They are large, fly silently and unfurl their long tongues in front of trumpet-shaped flowers like the ones listed above. They look like hummingbirds drinking nectar while suspended in the air. Their wings present handsome patterns, not as striking as those of butterflies, but very beautiful in a sedate way.

Other dawn- or dusk-pollinators are less familiar to most of us. A few species of bees do their job at night. The squash bee, although not quite nocturnal, is an early riser. It follows the schedule of squash blossoms and finishes its daily chores at early- or mid-morning when such blossoms begin to wilt. They are said to be up before sunrise, however I have never seen them so early.

Worth mentioning are truly nocturnal pollinators of a different stripe, bats. Most cactus bloom at night, they are strongly scented and produce big flowers with abundant nectar, just right for such large fliers. In the absence of bats the landscapes of the West would be profoundly different, without their rich flora of saguaros, barrel cacti or prickly pears.

List of articles

Pollinators in winter

2011-11-23T14:28:00.000-08:00

Wintering pollinators

Pollinators need habitat in winter. There are a few ways of providing shelter for them in our own backyards.

Hollow twigs provide refuge for many bees and wasps

Bee blocks are a very good substitute for the tree holes where many hibernating bees spend the winter

A halictid bee, Augochlora pura hibernating under the bark of a dead log

List of articles

Bees and vitamins

2011-08-27T15:04:00.000-07:00

It is said that bees and other pollinators are responsible for one third of all our food. Whether this is exactly right I do not know; but a trip to the grocery store confirms that a substantial part of our food comes from plants that have been pollinated by insects rather than by the wind: most vegetables and fruits, drinks such as coffee and tea; even beef, poultry and dairy products depend to some extent on pollinators because they feed on alfalfa or clover that have been pollinated by bees or other insects. Without pollinators we would be reduced to eating grains or cereals, potatoes, sea food and fish and very little else (and, perhaps, undernourished beef and poultry).

What is never mentioned but I find perhaps even more important than food quantity is quality. Many of our essential vitamins and antioxidants come to us courtesy of pollinators. Vegetables and fruits are loaded with vitamins such as beta carotene, vitamin C and a few others.

So, in summary, if it wasn’t for pollinators we wouldn’t be one third hungrier. Instead we would be one hundred per cent dead.

Sunnyside Dru: Bee Barracks update

2011-08-10T05:13:00.000-07:00

Sunnyside Dru: Bee Barracks update: "Earlier this year we posted a picture of this bee block. There are many variations to this all over the farm..small, not really noticeable, ..."

Mountain laurels instead of rose bushes?

2011-07-03T15:38:00.000-07:00

Last year I was traveling along the Blue Ridge in May and was pleasantly surprised at the beauty of the blooming mountain laurels. I had to look again and again to convince myself that what I was looking at wasn’t a rose garden but just a natural grove of mountain laurels.

I want that look in my garden. I have two rose bushes which I inherited from the previous owner of the property and I want to replace them. The advantages are obvious to me. Roses are not native; they provide no food for pollinators. Mountain laurel, on the other hand is pollinated primarily by native bumble bees.

It has a peculiar system of pollination. The unopened blossoms present little knobs which give them a funny look. When the flowers open, the function of these little knobs become apparent. They are pockets that hold the anthers (the pollen carrying part of the flower) trapped. It still doesn’t explain why this is so; in most flowers the anthers are free and exposed, better to spread their pollen at the slightest touch of a flower visitor.

The mountain laurel has a different strategy. The pollen is well protected against rain and wind, but, when a pollinator lands on the flower searching for nectar, the weight acts as a trigger, causing the taut stem of the anther to spring. The anther hits the pollinator gently on the back and gives it a dusting of pollen.

Mountain laurel flowers produce a moderate amount of pollen; but most of it ends up where it is intended, on the body of a pollinator, rather than being wasted in other ways. It seems like a very economic method to spread the pollen.

List of articles

Rain and Pollinators

2011-06-15T15:14:00.000-07:00

Where do pollinators go when it rains? You certainly don't see many of them around when it is pouring. They may be sturdy little fellows but they have some limitations. Wind or rain (or even cloudiness) can be too much for most of them. Cold weather also makes them think twice before going outside.

Gathering of male Andrena bees early in the morning

There are many different kinds of pollinators: bees, flies, butterflies, moths, and a few other insects; not to mention a few non insect ones such as many kinds of birds, bats and even a few other mammals. Let us look at one group in particular, bees. Bees probably do about 90% of all pollination so they deserve our attention. Bad weather is too much for most of them, but some fare better than others. A few bumblebees tolerate the cold of the Arctic Circle. Some bees fly at dawn or dusk or in the very early spring, although the majority prefers the daytime, sunny weather and warm temperatures. Wind is harder to overcome than chilly weather. There are physical limitations to flight, so when the wind reaches certain speed all flying insects find themselves grounded. That is why a steady breeze brings welcome relief from mosquitoes and gnats.

Rain is a serious problem to insects; a mere drop of rain is the equivalent of a big bucket to us; it would knock them down harshly. The weight of the moisture clinging to their bodies proportional to their own body weight would also be a major problem.

Insects are sensible enough to lay low when conditions are severe. Females return to their nests and stay there. Males, on the other hand, do not have nests to return to; they are not homemakers and know nothing about nests so they resort to a different kind of shelter. The males of many species seek each other company. They may stay in groups on flowers or leaves, or hanging from twigs. They clamp their strong jaws onto a twig and go to sleep this way. There are times in the early morning in which you can find one of these roosts. The insects may be dew covered and very sluggish and will need some sunshine before they can start moving around. Others cluster inside large flowers such as squash. These places offer some protection from the weather.

Carpenter bees spending the night clinging to a Passionaria flower

Probably these roosting places are not as secure as the nests where the females stay and this may very well be one of the reasons why male lives are shorter than female's. Males only mission in life is to mate; after that they are dispensable. Females, on the other hand, need to live a little longer in order to build nests, gather food, lay eggs and seal the entrance to their nests.

Sometimes, after a particularly rainy spring, trees produce very little fruit and one wonders about the connection between the abundant rain and poor crop. What happens is that the pollinators didn’t have enough opportunity to visit flowers because of the weather.

It is interesting that many native bees can face these hardships better than honey bees and turn out to be better pollinators under certain circumstances. Honey bees are very quick to return to their hives when weather conditions are poor. They also work shorter hours, starting later in the morning and quitting earlier in the afternoon. Some bee specialists say that native bees and bumblebees are not unionized and find themselves forced to work longer hours and under poorer conditions.

Roosting male bees

List of articles

Magnolias and beetle pollination

2011-06-13T17:54:00.000-07:00

Magnolias were among the earliest flowering plants, which evolved many million years ago, long before there were any bees. Butterflies and moths were also absent in those days. The only pollinators available were probably beetles and flies, the so-called “dumb pollinators”. This term refers to the fact that the late-comers to the world of pollination, particularly bees, can perform remarkable feats of memory and skillful manipulation of flowers. When bees entered the scene, perhaps twenty or thirty million years later (give or take a handful of millions), they took to the pollinating job with gusto. They became real pros which adapted to the ever growing variety of flowers and developed skills par with the complexity of these newly evolved plants. The same can be said of many butterflies and moths and also some wasps. That is how they earned the name of "smart pollinators".
Neither magnolias nor beetles are very specialized to pollination by insects. The flowers, though lovely have a very simple structure; for instance, there is no distinction between petals and sepals as in most other flowers. In turn their pollinators, beetles, are very clumsy at their task; sometimes they get carried away and eat parts of the flowers along with the pollen or nectar which they find there. Their mouth parts are made for chewing, rather than for gathering nectar and pollen, so they can’t be blamed for their sloppiness. The flowers, in turn, are adapted to this rough treatment; that is why magnolia petals tend to be rather leathery; and, most importantly, the seeds are well protected.

You develop a new respect for the pollinating responsibility of beetles when you take a look at the many families of these insects that visit magnolia flowers: sap-feeding beetles, tumbling flower beetles, leaf beetles and weevils, among others (or if you prefer their technical names: Nitidulidae, Mordellidae, Chrysomelidae and Curculionidae).

Bees, bumblebees, flower flies, a few types of stink bugs, leafhoppers and several other types of insects are also found visiting magnolia flowers attracted by their nutritious pollen and nectar.
But most of them arrive at the flowers too late, after the flowers are past their prime and are not receptive for pollination. So it is the beetles that carry the lion share of the responsibility for perpetuating these plants.

Nectar: drink with a zing?

2011-05-29T13:14:00.000-07:00

We saw that floral nectars aren’t just empty calories (Nectar: Breakfast of champions); they supply pollinators with valuable nourishment. The singular properties of nectar don’t end up there. When chemists continued analyzing the nectar of diverse flowers they found a few surprises.

In some instances caffeine or nicotine are added to the menu. Who would have thought! Then again, if bees love spilled Coca-Cola, it is perhaps for more than the sweetness. Do the clients of floral restaurants seek these stimulants? Do flowers find it important to indulge such demands? One thing is clear: some special ingredients in nectar must be important, both for the pollinator and the flower.

There are cases in which the sugar in nectar ferments into alcohol to the point that it may intoxicate thirsty flower visitors. Bumble bees visiting such flowers behave like drunken sailors, bumping clumsily into flower parts, shaking loose the pollen from the anthers and thus getting an extra dose of pollen dusting. Moreover, they neglect their fastidious grooming and remain rather dusty all over for some time. Perhaps this is beneficial to the flower which may end up getting more pollination under these circumstances. Nobody knows for sure but it is an interesting theory. I wonder whether the little gourmets develop a taste for certain vintages and visit more frequently the restaurants that deliver the desired beverage.

The flowers of a palm tree in Malaysia produce alcohol that can reach a concentration of 3.8%, comparable to some beers. And the tree smells like it! There is a little tree shrew, a fairly unusual pollinator, which visits these flowers assiduously. Up and down the trunk it runs visiting thousands of flowers. It is capable of drinking the equivalent of nine glasses of wine, day after day during the blooming season. Those who have studied this behavior claim that the animals show no sign of loss of coordination or similar consequences of heavy drinking.

Pollinators do a lot of traveling in their quest for nectar and pollen. They carry more than what is intended from flower to flower. Like tiny Typhoid-Maries they are likely to pick up and spread pathogens along with their legitimate cargo of pollen. Nectar is the perfect culture broth for many bacteria and fungi. Flowers can become quite sick so they need to protect their precious reproductive organs against infections. It should come as no surprise that they can produce an assortment of antiseptics. There are substances in nectar that produce peroxide, the same disinfectant your mother used to apply to your scraped knees.

Perhaps the most mysterious thing is that some nectars carry bitter tasting substances and even toxins. What would be the purpose of that? Some of the bad tasting ones deter only some flower visitors, while they don’t bother others. Perhaps the plant is being selective and inviting only those which are the most efficient pollinators and keeping others away. It is also possible that some pollinators can only tolerate a small amount of the bitter nectar, thus, abandoning the flower sooner and performing more pollination with less consumption of nectar. Let us remember that nectar production is an expensive investment for the plant.

Most plants produce toxins to protect leaves, stems, etc. against the hordes of herbivores. Ordinarily they filter out these toxins from the nectar. But there are some that fail to do so to some extent. This may be an unfortunate side effect, an instance of undesirable pesticide contamination. It seems that we are not the first ones to run into such a problem, plants made that blunder millions of years ago.

Nectar chemistry
Nectar, the first soft drink
Tiny treeshrews chug alcoholic nectar without getting drunk
Nectar, breakfast of champions

List of articles

Nectar: Breakfast of champions

2011-05-21T18:07:00.000-07:00

I used to believe that flower nectar was sugary water and not much else. That simple drink should be adequate for many of the insects that visit flowers. Sugar provides the fuel to power their flight, thus taking care of a fundamental need. Many insects have a very short adult life. They have already accumulated, during their larval life, most of the nourishment that they need as adults. In fact there are even some insects, such as the Luna moth, that do not feed at all as adults. Moreover, nectar drinkers often have other foods in their menu. For instance, bees collect pollen, as well as nectar, from flowers; wasps hunt insects. So it wouldn’t be surprising if nectar provided nothing more than sugar as a reward to pollinators.

I was wrong, but I wasn’t alone in my ignorance. Only recently, scientists have been able to study the chemistry of nectar, given the tiny amounts available for study. What they have learned in recent years surprised everybody. Nectar is a true cocktail including an assortment of substances, from nutritious to intoxicating, not to mention scented, colored or with preservatives. Flowers are known for the complexity and diversity of their shapes and colors. Now we know that their nectar can be just as rich in complexity and variety. Nectar drinkers seem to be connoisseurs of the restaurants they visit and flowers must have good reasons for developing such a complex menu to satisfy the demands of their clientele.

First of all the concentrations of sugars vary depending on a number of factors. Perhaps, the most important one is the most frequent visitors of a particular species. Butterflies and moths and some bees have very long tongues which they use like drinking straws. They visit flowers that provide a rather watery drink not likely to clog these very thin pipes. On the other hand, other insects, with shorter tongues, merely lap or slurp fluids and can take advantage of thicker nectar, richer in sugar.

In addition to sugar there are other substances in nectar. Like the power drinks used by athletes some contain ion supplements, such as potassium and sodium. Other common supplements of nectar are aminoacids, the building blocks of proteins. Let us remember that adult butterflies and moths cannot eat any solids. They have no chewing parts, only a long, thin tongue good enough for fluids and maybe the occasional pollen grain. As I mentioned before, most insects are short lived and may do fine without proteins in their diet, but the beloved monarch butterflies live for several months and have to make an arduous journey. They certainly need a well balanced diet; sugar alone would not suffice them.

There are other ingredients in nectar which I will discuss in future posts. I only want to mention here that in addition to nutrition, these substances may add flavor to this food making it more attractive to the pollinators and other flower visitors.

It is rather amazing to realize that we didn’t invent energy drinks; flowers did it millions of years ago. It gives me pause when I prepare to refill the hummingbird feeder. Are we turning our loved birds into soft drink junkies? Would they be better off without our help? I don’t feel too guilty because I know that they also feed on insects so they must be getting a balanced diet despite the empty calories at the hummingbird feeder. But, just in case, I will start growing plants for hummingbirds in my garden and cutting down on the junk food.

I can think of a few (natives only): butterfly weed, lobelia, beebalm, columbines, trumpet honeysuckle, penstemon, zinnia, nicotiana. Any suggestions?

Here is a list of “Top Ten” native hummingbird plants of the Operation Rubythroat web site.

Nectar, a drink with a zing

List of articles

Pollinator gardens and more

2011-05-03T12:39:00.000-07:00

A day doesn’t go by without hearing about a new pollinator garden. It is encouraging to see the growing number of people who realize that it is important to do something for bees and all the other pollinators. We are becoming increasingly aware of their important role in the pollination of crops and wild flowers and in the maintenance of ecosystems. We know that some pollinators have been in decline for a number of years, due in part to the loss of wild flowers.

In its simplest way a pollinator garden is a wild flower garden with some adequate habitat for nesting and, needless to say, free from pesticides. Now, a group in England, called the Cooperative, is taking this a step further by developing a more systematic approach to this matter. They are creating corridors for pollinator wildlife by the name of “bee roads”. Such bee roads would provide interconnected habitats for pollinators. Habitat connectivity is very important because it prevents populations from becoming isolated and thus it help maintain the biodiversity of the gene pools (all the genes present in a population).

They are starting small but plan to expand the project with the cooperation of land owners, by providing incentives for the creation of these roads of wild flowers along cultivated fields.

You can read more here News England and watch the BBC video (if you don’t mind the brief commercial at the beginning)

I hope that this initiative will inspire people in this country to start a similar project.

More on pollinator gardens in North America:
U S Fish and Wildlife
Bee-friendly gardens
Penn State
Xerces society

List of articles

Where have all the spring beauties gone?

2011-04-11T17:11:00.000-07:00

We are studying the pollination of spring beauties. The main pollinator of this lovely early spring wildflower is a bee, called the spring beauty bee (naturally). It is a species of Andrena, small, black and slender. Like all other Andrena, it has characteristic hairy spots between the eyes. This pollinator may visit other spring flowers for nectar, but it is thought that it only gathers pollen from spring beauties. To learn more about this bee, its geographic distribution, populations and its role in ecosystems, a number of volunteers throughout the eastern United States are collecting data of its visits to spring beauties.

So, I started prospecting my favorite spots where I had found these little gems of the woods floor in previous years. I was frustrated to find lesser celandines instead. I kept walking the familiar trail, and the scene was always the same: extensive carpets of glossy dark green leaves and vibrant yellow flowers. Only here and there did I see a sprinkling of spring beauties, fresh leaves of trout lilies and a few other early flowering plants of the woods.
I must say that lesser celandines are really beautiful. No wonder why they were brought to this country as ornamentals! And no wonder why many garden centers sell them and gardeners buy them! The sinister side of this invasive beauty doesn’t seem to register in the minds of commercial centers and uninformed gardeners. But conservationists see something else. Lesser celandine is replacing some of the native plants, creating a cascade effect on the balance of nature. Native plants feed native pollinators and many other insects, which in turn, benefit other members of the natural community.

I turned my attention to lesser celandines: Do they get any visits by pollinators? Do they provide any services to the natural community?
I sat down for hours on a small picnic stool surrounded by blooming lesser celandines, camera in hand, ready to snap pictures of pollinators; hardly any came. I will continue to observe lesser celandines, but I fear that I already know the answer: specialist pollinators, such as the spring beauty bee or the trout lily bee are not likely to visit these invaders of forest and gardens, useless to them. I know that in their native land lesser celandines are visited by mutually adapted pollinators and that they provide food to some caterpillars (which in turn feed birds), but nobody seems to find them nutritious in this country.
Alarmingly, this plant is a very successful invader, with means to spread by bulbs and with the ability to sprout so early in the spring that it has a head start over the other plants in the forest. Thus a rent appears in the web of life. The more this successful invasive keeps spreading, the larger the rent becomes.

Update, April 28: Fortunately I have been seeing lots of spring beauties in other places. Let us hope that lesser celandines don't spread there too.

List of articles

Death among the flowers

2011-03-26T13:11:00.000-07:00

Pollinators have such a glamorous job. They fly from flower to flower collecting golden pollen and sweet, delicious nectar. What could be better? Indeed it is a wonderful job; but just as there are snakes in paradise, there are hidden dangers among the lovely flowers. Life can be very cruel in the garden.

Ambush bugs have a very well deserved name. They wait in hiding among the flowers. Sometimes they are very hard to spot because they hide among the petals, only their alert eyes and antennae can be seen. Their sharp beaks, loaded with poison at the ready and their powerful front legs prepared to snap with vise like action.
Ambush bug, Phymata

One sunny day I was walking in the garden enjoying the comings and goings of diligent pollinators when I spotted this little killer, a jagged ambush bug. One look at its contours renders the name self explanatory. Perhaps the jagged shape makes it hard to swallow by would be predators. It also must help on disguising its appearance.

I snapped a couple of pictures and was about to move on when I saw a bumble bee land on the flower. The next few photos were taken less than a minute later and show the fate of the unfortunate bumble bee. Had it been more careful it would have escaped his fate. The amazing thing is that there was no struggle. The venom of the ambush bug must be so powerful and fast acting that it paralyzes a victim twice the size of the killer instantly.
Male two-spotted bumble bee, Bombus bimaculatus

Being a pollinator can be a hard life. But that is the way it is for everybody out there, including the killers.

Indeed, life and death go hand in hand in the garden.

List of articles

My bees and climate change

2011-02-16T15:29:00.000-08:00

It is February 16th and the weather forecast for the next few days shows temperatures in the sixties. I am concerned about my bees. I hope that they don’t wake up too soon.
I have been raising native, solitary bees for the last few years. They are not like honey bees: they don’t make honey or wax. They live alone, each mother raising her own babies. They are gentle and not prone to stinging. I am also told that, if they do sting when molested, their venom is very mild compared to that of honey bees and yellow jackets.

I am not interested in honey or wax, so this matter doesn’t bother me. I like these native bees because they are very good at pollinating wild flowers; they also pollinate some fruit trees and other crops just like honey bees.

My bee houses don’t look like hives at all; they are blocks of wood with holes about the size of a pencil. Each mother bee claims possession of one hole, then she gathers enough pollen and nectar for one baby, lays an egg at the far end of the hole, builds a wall with clay and starts a second cell for the next baby until the whole tube is filled. Then she double-seals the entrance with clay and starts another nest if she has enough time. These bees are very short lived and by June they are mostly gone; if you see one at that time, its wings look frazzled and you can tell that it won’t be able to fly and carry pollen much longer.

Be it as it may, the system works quite well for these bees. Each spring a new generation emerges from the nest and starts the cycle again. Yes, the new generation has been out of sight all that time. The egg laid in the previous spring became a hungry grub that ate all the supplies, then it metamorphosed, first into a relatively immobile pupa and then into a winged adult. Without ever leaving the nest it went to sleep and stayed put for all those months of summer, fall and winter.

How do they know when it is time to emerge and leave the nest? It may be a combination of a biological clock and weather conditions. The fact is that they emerge in the spring, just around the time when numerous flowers, rich in supplies, are blooming.

My bees found the recently placed bee houses three years ago in mid-April, when the weather was quite balmy. Who knows where they came from but come they did and built their nests. The next year, there was a sudden burst of spring weather, warm and sunny, on April first. Taking the cue from the weather they started chomping away the hard clay front door and inner partitions built by their mother almost a year earlier and hurried to leave the nest, buzzing along; the ones farther back pushing their brothers and sisters in their urge to see the world.

The next few days my bee houses buzzed with activity: flirting, mating, inspecting the now empty holes, as well as any other hole of a similar size. Soon only the females remained. They kept coming, loaded with supplies and disappeared inside. Sometimes they spent some time sitting at the door, only their antennae sticking out. They seemed to be munching on something now and then. Who knows where the males went after they mated! This is their sole contribution to the next generation.

A year later the first spring-like day was March 19 and just like the previous year, although almost two weeks earlier, my bees emerged and started their activities, no less entertaining for the fact that I had seen it all the previous year. Actually there is always some novelty; you notice new details for the first time and marvel at the things such tiny and alien looking creatures are capable of.

But now, it sounds like there will be a balmy warm day in the middle of February, despite the heaps of snow still present on the ground. What will happen to my bees? Will the biological clock prevail over the cues from the weather and will they wait for the second bout of spring weather? Or, will they emerge too soon? There is no food to be had anywhere for them, no flowers. . . Some of the flower bearing plants haven’t even begun to grow because the snow storms have been hard and heavy and the ground hasn’t had time to thaw, nor the plants a chance to grow.

What will it be? As I write this I wonder what to do if my bees show up tomorrow: supply them with some small containers of sugary water? That may help, but, do I want to interfere with nature? These things may have happened many times before and the bees survived well enough to this day. However, it is possible that climate change has been accelerated by humans; this change might be too fast to allow some of our precious creatures to adapt. If bees and flowers get out of sync they will suffer. They may even be pushed to extinction. I sit and wonder.

List of articles

Symmetry

2010-12-03T13:21:00.000-08:00

I am looking at a picture I took several years ago of a bee visiting a sunflower. The head and front part of her body are metallic green. The last part, the abdomen, is striped black and white. A very striking little bee, a jewel contrasting with the golden yellow of the flower. She carries two enormous baskets loaded with pollen on her hind legs. These ingenious organs resembling grocery baskets are made of abundant longish feathery hairs that hold the loose pollen grains. She keeps working the little florets at the center of the flower in search of additional pollen and some nectar to carry home for her children. These bees can be quite abundant in suburban gardens but often go unnoticed by human visitors; their role in the garden remains mysterious and irrelevant to the gardener, no matter how conscientious he or she is about the needs of the plants. These bees are so unknown to most of us that they haven’t even earned a common name. Scientists refer to them by the intimidating name of Agapostemon virescens. I wish I could tell you what Agapostemon means; all I can say is that virescens refers to their green color.

I notice in my collection another picture of a bee on a sunflower. It looks like a mirror image of the first; same colors, same posture, same heavy load of pollen. Except that this picture was taken four years later. It isn’t the same bee, not even a sister; more likely it is the great-great-granddaughter of the first. I delight on the symmetry of these far removed generations. Life goes on in the wildflower patch. I wonder if the flower is also the great-great-grandchild of the first one. It is possible. Symmetry of a different dimension: the flower nourishing the bee and her brood so she can carry on year after year and the bee ensuring that the plant can make seeds and reproduce. Two distinct threads of life intertwined for eons.

Lawn for Pollinators. Part III

2010-10-10T13:44:00.000-07:00

As mentioned many times before, it is preferable to have a wildflower meadow than a large expanse of lawn; however, some areas need to be mowed to allow walking on them or to enhance the garden. Grass companions, plants that are good to pollinators and to wildlife in general are welcome in such areas. They are healthy for the lawn, can be quite pleasant to look at and can provide food for many types of wildlife including bees, butterflies and birds.

One grass companion that is good in the fall is the aster, or several species of asters. Their pretty, daisy like flowers add a sparkle to the uninterrupted greenness. The genus Aster is rich in species; some of them are so similar that even botanists have trouble telling them apart. Many are used in wildflower gardens and wildflower meadows; they can be too tall to become part of a lawn; a few manage to escape the meadow and survive repeated mowings, growing very low and close to the ground. Thus they become grass companions.

Here is a field where asters are interspersed with the grass; if mowing isn’t too frequent they manage to grow several inches tall and to produce many flowers in September and October. If the lawn receives more frequent mowings the plants hug the ground and still produce a pleasant array of little flowers. Finally if the lawn is mowed closer to the ground and with higher frequency the asters may fail to bloom, but they still provide a nice ground cover, green, thick and supple.

Such flowers don’t fail to attract a considerable number of pollinators; I see them in abundance when I walk through a field where asters are accepted as part of the lawn. Skippers are very common visitors; other flashier butterflies, such as fritillaries and buckeyes, also show up.

A variety of Syrphid flies or hover flies come to visit the aster blooms. They may not be very efficient pollinators but they perform another very important function: their babies devour aphids; so they are welcome visitors in any garden.

Finally, some of the most important pollinators come to the asters: many sorts of bees, among them the beleaguered honey bees, several types of bumble bees and a few other native bees of the solitary type.

Lawn for pollinators. Part I
Lawn for pollinators. II
List of articles

Jack-in-the-pulpit and its cruel deception

2010-09-19T08:41:00.001-07:00

Early in the spring you can often see Jack-in-the-pulpits in your walks through the forest. The peculiar shape of its flowers gives it its name, a big leaf, the spathe, makes up the pulpit and a rod inside, the spadix, is the person. It is the spadix that carries the minute and numerous flowers; some plants have only masculine flowers inside the pulpit and others have only female flowers. How are they pollinated? They don’t have flashy colors nor perfume, they are not placed in a prominent place like most flowers but they are close to the ground and hidden beneath the leaves. So what kind of insects do they attract? The jack-in-the-pulpit belongs in the same family as the calla lily and the skunk cabbage, this family is notorious for using all kind of ruses to attract pollinators without giving them any reward and Jack-in-the-pulpit is no exception.

Apparently the flower of Jack-in-the-pulpit smells somewhat like mushrooms and attracts fungus gnats. The insects fall inside the pulpit and if it is a male flower they get covered with pollen in their effort to escape. The sides are so slippery that they can’t climb up and keep falling back to the bottom, fortunately there is a small hole at the base of the pulpit and they eventually find their way out; they leave the place no worse for the wear, although probably somewhat mortified by their mistake. They don’t seem to learn their lesson and keep on venturing inside other Jack-in-the-pulpit flowers. If they fall into a female flower they leave their load of pollen on it, but in this case they cannot escape, there is no opening at the base. Every maturing fruit of a Jack-in-the-pulpit contains one or several entombed gnats wrapped by the dried up spathe. That is how this plant repays its pollinators, a cruel deception indeed!

Lawn for Pollinators. Part II

2010-04-24T08:16:00.000-07:00

Winterthur in the Brandywine Valley near Philadelphia. Large expanses of lawn such as these are being turned into meadows with paths rambling through them.

We have covered an astronomical number of square miles with lawns, lawns that are in most cases deserts, useless to wildlife. That surface is comparable to that of Pennsylvania, New Jersey, Delaware, Maryland and Rhode Island combined.

If you live in the West you may prefer to see this surface as equivalent to that of the state of Washington.

Do we need that much lawn? Much of it could be turned to meadows or other plantings according to the mantra: "Less lawn, less mowing, less pollutants, more natives". This is being done in places such as the New River Gorge National Park Visitors Center in West Virginia. The meadows and grassy paths are pleasant to the eye, beneficial to wildlife and healthier for everybody.

New River Gorge Bridge Visitor Center. WV

Lawn for pollinators. Part I
Lawns for pollinators. Part III
List of articles

Lawn for Pollinators. Grass Companions

2010-04-04T08:02:00.001-07:00

Yellow violet
Ordinarily a lawn is a desert, very unwelcoming to wildlife from tiny insects to birds. It doesn't have to be this way. A lawn can supply food for pollinators and even for birds; it can also provide housing for some pollinators.
We can make our lawns more nature friendly by readjusting our notions of aesthetics: a perfectly manicured lawn that looks like an indoor green carpet need not be the only ideal of lawn beauty. Instead, a lawn with some variety of plants which includes a few broad-leaved “weeds” has its own kind of natural beauty; let us call them “grass companions”.
The very first step, naturally, is to avoid pesticides and herbicides whenever possible. The choice of broad-leaved small plants that you can allow in your lawn is a little trickier and it may take some time to get the right combination; but the final product would be a pleasant lawn that requires less care and less fertilizing, providing more resilience to droughts and pests in addition to being more hospitable to desirable wildlife. There are a number of little flowering plants that grow in lawns completely uninvited that we are constantly trying to eradicate; however we could start welcoming some of them. Ideally, you want only non-invasive lawn flowers, preferably native ones, but this would require effort beyond that which any gardener would be willing to invest. So it makes sense to accept some non-natives too; after all most lawns are made up of grasses which may not be native to your region.
Some of my favorite grass companions, such as violets, bluets and spring beauties do well only where foot traffic is minimal, or where mowing is less frequent. Others can take a good amount of abuse:

Bluets
• Blue eyed grasses (Sisyrinchium, several species) not a true grass but a member of the iris family, with pretty blue flowers.
• Cinquefoils, (Potentilla).
• Wild strawberries (Fragaria, several species). The five lobed leaves of this and those of cinquefoils are very similar in appearance.
• Yellow violets (Viola pennsylvanica), and other kinds of violets too.
• Spring beauties (Claytonia)
• Wild geraniums, crane’s-bills (Geranium)
• Azure bluets (Houstonia caerulea).
• Speedwells (Veronica), there are several species, some of them are native others introduced.
• Wood sorrel (Oxalis acetosella), used as ground cover by some gardeners.
• Chickweeds include two genera: Cerastium and Stellaria. They are also known by several other common names; some species are native and small enough to do well in lawns, such as field chickweed, (Cerastium arvense) and star chickweed (Stellaria pubera).
• Smartweeds, knotweeds, many species in the genus Polygonum; some are small enough to do well in lawns. There are some native species and others that are introduced.

Among the non-natives, a very useful one is clover, (white clover, Trifolium repens) a European plant very well established in the United States; it used to be included in grass seed mixes because it helps fix nitrogen, enriching the soil as a consequence. There are a few species of clover that are native to some regions of North America. Chickweeds, also known as starweed, bindweed, winterweed, as mentioned above some are native others aren’t; the seeds of some are eaten by some birds, hence the name chickweed. Gill over the ground, or ground ivy (Glechoma hederacea), is rather pretty but it can be very invasive. Thyme, (Thymus several species) has been used as ground cover sometimes. Scarlet pimpernel, (Anagalis arvensis) a European plant with small pink flowers. Dandelion (Taraxacum officinale) is among the non-native invasives which you may not want to see around. Some think that it doesn't provide much of anything to pollinators despite its colorful flowers, others fear that it may compete for pollinators with some native flowers, reducing their pollination.

Chickweed
These are just a few of the "grass companions" that do well in my region, the Mid Atlantic. Other areas might use some of the same along with other “companions” based on regional conditions.
A simple practice that can be helpful to pollinators in your lawn is to allow some bare spots in dry and sunny places that can be used for nesting by bees and some insect eating wasps. Some leaf litter, especially on or near flower beds, can provide shelter for fritillary caterpillars and hummingbird moth caterpillars and a few other wintering moths and butterflies.

Lawn for pollinators, part II
Lawn for pollinators, part III

What is good for the birds is good for the bees

2010-03-05T07:22:00.000-08:00

Let us say that you want to help pollinators by creating a habitat in your garden that is beneficial to them. If you are a nature lover and have been trying to attract birds to your yard, chances are that you have already been helping the pollinators without knowing it.
At the top of the list of what you can do for both birds and pollinators are two things: grow native plants and avoid pesticides. By native plants we mean not just native to North America, but to the particular region where you are located.
Plants and animals of each region have been adapting to each other for eons. Local plants usually provide the best food and shelter for the local wildlife. More specifically, wild flowers provide the right cues and produce the right food for pollinators, e. g.: scent, kind and amount of nectar and pollen, right colors and shape. Many times, cultivars and non-native plants lack one or the other of these features and are worthless to native pollinators. Of course, this is not always the case; many species of bees visit the flowers of introduced fruit trees and butterflies find the non native butterfly bushes to their liking; but these are the exceptions, rather than the rule.
Dead trees or snags or dead branches provide housing for pollinators, they are also good for birds. A brush pile, some leaf litter, keeping dried up tall grasses all winter, also turning some of your lawn into a meadow, a variety of flowering and berry producing shrubs and trees are, once again, good for both kinds of creatures providing food or shelter or both.
I would add to this list small lawn "weeds", all those little broad leaved plants that some people consider unsightly, are helpful to pollinators and are actually beneficial to your lawn, for instance, enriching the soil in the case of clover. So, if we could change our vision of what is esthetically pleasing we would be benefiting our precious wildlife.
Finally, a few bare spots in the lawn are not a bad thing; some pollinators nest in the ground, building pencil thick tunnels and storing pollen and nectar at the bottom of such tunnels. Mulch, gravel or a very thick lawn may prevent them from finding the right spot. Is it too much to ask to allow a few bare spots in the farther areas of a yard where they are out of sight?

Our friend the elephant mosquito

2010-02-25T17:46:00.000-08:00

Male elephant mosquito sipping nectar of goldenrod flowers. Notice the elaborate antennae

Elephant mosquitoes have a well deserved name; they are giants among mosquitoes. Their wing span reaches almost half an inch. They have a formidably long proboscis; you would think that they may have a vicious bite. Not so, the good news is that they do not feed on blood like many of their relatives; instead they are often found on flowers, drinking nectar with their long tongues in a poor imitation of butterflies. Just like butterflies they carry pollen from flower to flower, so we should welcome them in our gardens.

The delicate long tongue stretches and bends almost like that of a butterfly. Video

The scales that cover their bodies are somewhat iridescent and their legs are thin and long, even more so than many mosquitoes. The males have long, feathery antennae of an intricate shape; better to detect the vibrations, the buzz emitted by females.
Not only are they pollinators but they also have a remarkable virtue. They lay their eggs in water, not in large bodies of water but in holes such as old tires or tree holes; the very same places where the larvae of many species of mosquitoes grow and prosper. The nice thing about elephant mosquitoes is that they feed on the larvae of their relatives. So, the adults are well behaved and don't hurt us, instead they pollinate flowers, and their larvae provide another service to us by feeding on the pests that give us so much discomfort or even transmit diseases. So, let us celebrate our friend the elephant mosquito.

Bumblebees and Turtleheads

2010-02-05T16:02:00.000-08:00

Some flowers are easy to pollinate, wide open, with free access to pollen and nectar; an insect with no skills and no elaborate equipment can collect food without difficulty. Other flowers make things interesting; their pollinators have to figure out how to enter them and how to reach the hidden rewards. It is great fun observing the labors of some bumblebees visiting one of these "difficult" flowers.

Last summer my friend's garden was brimming with turtleheads and the turtleheads were brimming with visitors, not a great variety (I only saw bumblebees) but a large number. This flower deserves its name, it looks like the head of a turtle, with powerful jaws and a large cavity inside, where the nectar is hidden and where the important parts of the flower lay, the male parts which carry pollen and the female parts, which receive the pollen and produce the seeds.

Young flowers, like the one above are not quite ready for visitors and clench their jaws tightly. This bumblebee tried in vain to enter the blossom and never got more than its head inside so it gave up the effort and tried a different one.

The next flower must have been just right, the entrance was slightly open, and this time it entered without difficulty and spent several seconds out of sight collecting whatever reward it could find, perhaps just pollen or nectar, more likely both.

The fun started when it tried to leave the same way it came. It kept backing up but, no matter how hard it tried, it just couldn't get out tail first; so it went deeper inside to make a U turn; out it came, head first and briskly flew away.

It promptly learned the way in and the way out and when it entered other flowers it turned around without hesitation and emerged head first. Interestingly, in some cases it entered the right side of the mouth and left through the left. Not all flowers were so hard to exit; some, maybe older ones had loosened their jaws a little further, the mouth stood agape and bees came and went with no difficulty and no need to turn around.
You can see it all in a video.

It makes you wonder why bumblebees persist on visiting difficult flowers and why flowers make things difficult for their pollinators.
From the point of view of the flower, it must be advantageous to select its clientele, allowing only those with the right equipment (e. g. a long tongue, powerful muscles, the correct size) and with enough intelligence and memory to figure out what to do. In this way they ensure that their pollen gets carried to other flowers of the same species and doesn't get wasted on different flowers. To satisfy the demands of such a clientele the flower has to offer the right incentives. So, such flowers are likely to yield large amounts of nectar, richer pollen or both.
Thus, the reasons for a bumblebee to visit such flowers become obvious; it is worth the extra effort if the recompense is far superior to the one offered by plain, easily accessible flowers.

Bumble bees, the pandas of the insect world

List of articles

A Night in the Life of a Working Mother

2010-02-03T11:46:00.000-08:00

It is spring but you wouldn’t know it judging by the temperature. Here in such northern latitudes, Ellesmere Island to be more precise, winters are long and brutal; spring and summer last no longer than a sigh. So, this morning the air is crisp, and I would call it bitter, as I am not used to this weather. The frost covered grass crunches under your foot with each step you take. However, there are flowers all around. A carpet of small flowers is growing hastily so that the plants can complete their cycle before winter arrives. But, why are there so many flowers? Who visits them and pollinates them? Certainly not honeybees. They can’t endure this climate. Bumblebees! that is who. They are hardy and well prepared for such harsh climate.
Let us look at one in particular, Ms. Bombus, a plump and fuzzy little lady that has been very busy for the past few weeks. She has found an abandoned vole’s nest; has redecorated it inside making it suitable for her coming family. She has prepared several enormous wax pots full of nectar or pollen. They are enormous compared to her size; to us they are nothing but thimblefuls. Then she has laid six little eggs that, by now, have turned into squirmy, hungry babies that she feeds several times a day, alternating with trips in search of more food.
Tonight, she is very concerned. She doesn’t need to watch the weather report on television in order to know that a cold snap is coming, colder than usual, that is. Bumblebees that live in other regions can wait to start a family until the weather is balmier but she doesn’t have that luxury. The growing season is too short so she had to speed things up despite the risk involved. The coming cold could kill her precious babies.
Fortunately she is well prepared to take care of them. She is covered with a thick and fluffy fur all over most of her body. On her belly she has a bare patch that reminds us of the brooding patch that many birds have when they are raising a family. So, just like a mother bird she lays spread eagled on top of her brood and thanks to her thick fur coat she is able to keep them warm for a while. Soon this is not enough because the temperature keeps dropping, so she begins to vibrate her strongest muscles, the flying muscles of her chest. This time she isn’t flying, just generating heat that is transmitted to the babies beneath her. She keeps shivering this way hour after hour, as long as needed. This effort uses up lots of energy and makes her very hungry. With great foresight she had placed her nursery and herself just on front of one of the wax pots brimming with honey, an excellent fuel, and she periodically drinks from it. The night goes on, grueling and relentless, until finally the sun begins to shine and to warm up the fields. Only then can Ms. Bombus relax and rest, still covering her precious family a little longer. Later on, when it is warm enough, she moves away from the babies and with one final tender look at her wiggly and happy gang she heads for the front door. Bleary eyed and sore muscled, she faces her day job, a full day of gathering badly needed provisions for her brood and for herself.

Bumble bee life cycle

List of articles

Floral Emissaries

2010-01-03T08:03:00.000-08:00

The raising sun turns the meadow into multicolored blankets of sparkling dewdrops. One flower stretches its petals lazily; it is still too early. She sets the table with a scented tablecloth, arranges bowls brimming with nectar; the anthers full of pollen have burst open exposing their golden dusty treasure and she wonders: Will the visitors come? Sadly, the weather turns bitter and windy and the sun finally refuses altogether to come from behind the clouds; wrong weather for winged visitors.

The next morning the wind is gone; the sun begins to warm the land and melt the dew drops so our flower feels her hopes rise. She is not alone; many others show their charms letting their aroma float in the breeze with the same hope of attracting guests. Better this way, so the callers can carry love messages between them.

The sun keeps climbing and finally a buzzing sound announces the arrival of one of the anxiously awaited visitors. A shiny metallic green bee stops briefly at a nearby blossom and then comes to her. Wisely, she has painted darker lines that point the way to the hidden nectar; thus the guest has no trouble finding it and drinks it avidly and briefly. The cunning flower has prepared just enough nectar to attract a visitor, but not so much that the bee would become satiated and return home without further visits. The guest brushes accidentally against the anthers and some pollen sticks to its hairy body. This is no accident; the flower has placed things just right where she wants them; now her pollen will travel to other flowers.

A parade of winged travelers follows on the next few days. Not all of them are shiny bees, there are others: fuzzy bumblebees, flower flies, a few flashy butterflies and moths and even a beetle.

Finally the pollen is all gone and the anthers begin to wilt. But the flower isn’t done yet because deep inside the ovary, at the very heart of the blossom, sit the future seeds. Now the ovary begins to bulge and its tip at the end of a little tube, the stigma, glistens with a sticky substance meant to receive the pollen from other flowers, the love messages brought unwittingly by the visitors. So the flower keeps inviting guests with its nectar and hoping that they come loaded with other pollens and ready to leave some of their cargo behind. Pretty soon the grains that were left on the stigma will begin to make their way toward the carefully sheltered future seeds. Only now is the flower satisfied of a mission accomplished and only now she allows the colors to fade and the scent to disappear; the petals shrivel and will soon fall to the ground.

Only the ovary remains with its seeds and with all the promises of generations to come. Later on it will become a juicy berry that will attract another kind of visitors, hungry birds and other small animals; they will carry the seeds, adventurous explorers, to farther meadows, to a new life away from the mother plant. But, that is another story.

For the Love of Flowers

2010-01-02T17:30:00.000-08:00

Andrena, the bee, was sleeping her long slumber, comfortably inside her underground refuge, when something began to arouse her. She had been born the previous spring inside this cozy underground cell and she had grown well nourished by the mixture of flower’s nectar and pollen that her provident mother had stored. Later on, like the sleeping beauty, she had fallen into a deep trance for many months. But now it was spring and the soil was beginning to warm up. Did the warmth wake her up? Or was it some mysterious internal calendar? Suddenly that cozy cell that had been her nursery, her castle, her realm, her whole universe through the hot months of summer and cold ones of winter had become an intolerable prison. She had to get out.

Moved by this urge she began digging her way out. Her legs, never used before, were powerful enough to start loosening the earth that blocked her way to the outside world. With an unerring sense she moved toward the surface, perhaps following some ancestral memory of that world.
The task was arduous but she was young and strong and determined to find her way. It took her several hours and when her head finally emerged at the surface all her senses were bombarded by an accumulation of new sensations: light, colors, smells . . . She tried her wings for the first time and suddenly she found herself airborne. She marveled at her capacity for flying, zigzagging, rising and falling, making sudden turns. The surrounding world, immense and full of sunshine and strange sights, and her just discovered faculties were intoxicating. She kept coming and going taking notice of this unfamiliar land of her birth and its landmarks. She didn’t seem to get tired; there was so much to see. A hungry bird tried to catch her and missed, not because of her skill, but by sheer luck. She would learn to be cautious later on.
That morning she learned that she belonged to a small village of bees that, like her, were emerging from their prolonged sleep and getting drunk on light and air and new experiences. Their wings reflected the rays of the sun. Sometimes, if you walk on a meadow at the right time, you can see them against the sky like constantly moving dots of light.

A dogwood blossom makes a convenient waiting room for a group of boy bees spending the night together in wait for the girls

There were some males among them; some had emerged the previous day and now, past their first exhilaration they were moved by another urge that kept getting stronger by the minute. The scent of the females acted like a magnet and several, full of eagerness, approached and surrounded our little bee. She resisted their advances, not for lack of desire, which she was beginning to discover, but because she wanted only the best suitor. That would be her legacy to her children: the best father that she could find. One male prevailed over the others and joined with her. Now, in delirious ecstasy, both of them, linked by love, rose in the air and flew to a nearby branch where they could enjoy their time together in seclusion.
After their romance and carrying inside herself the sperm of the male, Andrena became all mother. Only one motivation would dictate her actions from now on: to ensure the best for her future children. She was passing on her mother’s heritage even though she would never know neither her mother nor her children.
She started the search for a nest site. What better place than the one her mother had chosen the previous year? It was a patch of soil, warm and with plenty of sunshine, safe from floods and not chocked by vegetation. She landed and started walking in circles looking for the best spot, but somebody else, perhaps her own sister, had already started setting housekeeping there. An angry buzz let her known that she was not welcome nearby. No problem, there were several similar spots not far from this one and she had no trouble finding a good one.
Andrena began digging the hard soil, just like her mother had done a year ago. It was harder than digging up from her cell; the soil was compacted and she had to use all the energy of her young jaws and legs. She kept working full of determination until she realized that she was getting hungry and thirsty.
She flew away from her nest searching for food. A delicious aroma told her that she had found what she was looking for. There were many flowers in the meadow, she landed on an open blossom, found its nectar guided by the scent and drank it thirstily. Andrena went from flower to flower until satiated, then returned to her task.
Back to work she went digging deeper and deeper. Evening came and she needed to rest. What better place than the tunnel she had dug? It was safe there and protected from the night chill. Andrena slept comfortably. The next morning, when her muscles were warm enough, Andrena resumed her work until something told her that she had arrived at the right place; then she started digging a side cavity, this one was a chamber like the one that had sheltered her through her infancy and long sleep.

A mother Andrena gathering food for her babies; her feathery legs make good baskets for the pollen

Now she needed to prepare the chamber for her offspring. That meant many trips to the meadow full of flowers. There she loaded rich pollen in the baskets on her legs and nectar, which she carried in her crop. It took her many trips to have enough for her purpose and another day passed by. She kneaded the pollen and nectar into a thick paste and made it into a tidy ball that nearly filled the whole cell. Satisfied, Andrena laid an egg on top of this loaf and sealed the chamber with some soil.
Once again she kept digging another branch of the tunnel, making a new chamber, gathering food, laying a new egg and so on. The days flew by. Sometimes she couldn’t go to work because the weather was foul so she hunkered down, feeling safe in the darkness of her tunnel. One day our little bee escaped a sudden death without knowing it. When she approached a blossom she noticed something different but didn’t give it much importance. Fortunately for her, another bee beat her to this flower. Somewhat annoyed Andrena flew to another one without noticing that a crab spider had caught the other bee in her clutches and paralyzed her with her poison.
All that coming and going wore out her thin wings. They began to fray at the edges and so the day came when, after gathering her usual load of supplies in the meadow, she tried to take off but the extra weight and her aging body and worn out wings prevented her from doing so. She tried again and again but the wind kept slamming her against the ground. So finally, with a sigh and without regrets she surrendered to her fate, knowing that her mission was complete, the new generation was well provided and would repeat the story next spring.
Thus ended one little life made of flowers and sunshine, of dark tunnels and security.

The pure magnificent green bee

2010-01-01T13:09:00.000-08:00

A female Augochlora pura gathering pollen on her leg baskets

Among the many metallic green bees that you see in the summer there is a particularly beautiful one, Augochlora pura. It doesn't have a common name but its scientific one means "pure magnificent green" and it is a very fitting one.
You may have seen this little jewel diligently visiting flowers to gather food for her family. You would be surprised to find out where she takes her load of pollen and nectar. If you could follow her, which isn't easy, you would see her arrive at an old fallen log and disappear inside a crack of the loose bark. That is where she has started building a home for her babies, in the space between the bark and the log. She builds chambers using her own saliva, some wax from her abdominal glands and loose debris, abundant in such places. Later on, she kneads the cargo that she brings from flowers into tiny loaves that look like golden tiles with which she paves the inside walls of the chamber. When there is enough food to feed one baby all the way to adulthood she deposits just one egg and seals the cell; afterward she starts building another one and so on.

A dead log, home to a few metallic green bees

An unhappy mother whose nest has been disturbed when I lifted a chunk of bark. You can see the ripped open cell, where the larva lays surrounded by a nice supply of "bee loaves" made of pollen and nectar

The babies grow on such rich food and emerge in the fall. By then the mother is approaching the end, her wings are torn and frazzled. The bees of the new generation, on the other hand, have a youthful look, with glossy wings and nicely coated by delicate hairs; these are the ones you are likely to see in October and November.

Young females getting ready to hibernate in late fall, November

The young bees mate promptly. This is the end of it for the males who die shortly afterward. But the recently mated females visit some of the abundant fall flowers stocking up on food to see them through the long winter and get busy finding cracks under wood to spend the cold month in safety. By the end of November you are not likely to see any more activity from these handsome bees; but rest assured that they will emerge from their seclusion next spring when the sun warms up the land and when blooms are ready and waiting for them.

POLLINATORS. Robbers and thieves

2009-12-28T13:09:00.000-08:00

Some flowers allow only specialized pollinators. They place their nectar out of the reach of most visitors and only those with a long enough tongue can reach it. Such is the case of the bee balm or monarda; a flower visited by hummingbird moths and bumblebees.

A hummingbird moth unfurls its long tongue and sticks it inside the equally long throat of a bee balm flower.
The tongue of a bumblebee isn't as long as that of moths or butterflies, but by burying itself into the flower this visitor can reach the store of nectar without difficulty.

These visitors approach the flower the "legitimate" way, meaning that they touch the pollen carrying parts and also the female parts of the flower by entering it this way. When they do so they carry pollen from some flowers to others and accomplish pollination. Everybody benefits; the insects get nourishment and the flowers are pollinated.

However this flower's strategy may backfire when clever and lazy flower visitors take a shortcut and steal the nectar. One very common robber is the carpenter bee; with its powerful jaws it can easily slash through a flower's tissues. Here a female carpenter bee is opening the throat of a bee balm flower. When this bee goes directly to the nectar bypassing the sexual parts of the flower it doesn't pick up or carry pollen. As a consequence, it doesn't help the flower at all.

A carpenter bee stealing some nectar

DECEITFUL FLOWERS. Lady slipper

2009-12-16T13:10:00.000-08:00

In most cases the relationship between flowers and their pollinators is a wonderful partnership in which everybody wins; but there are exceptions. In some cases, insects exploit flowers and take their offerings without returning the favor and in other cases it is the flowers that exploit their visitors.
Many orchids use a wide range of deceptions; some, such as the lady slippers, engage in a rather innocuous deceit that only causes the insect a minor inconvenience. This flower has a very peculiar shape, with the lower petal expanded into a bag. The purpose of this bag is to act as a temporary trap.

The drawings show a flower cut through the middle to illustrate what happens.
It is not known exactly what the attractant is, but it is powerful enough that several kinds of bees come to the flower seduced by its appeal.
The bee perches on the edge of the sac and often loses its footing and falls inside; once there it struggles to get out but the inside is slippery and the curled lip of the bag makes it hard to get out. Fortunately for the bee there is a escape route.
Toward the back of the flower there is a ladder made of hairs that leads to a tunnel. There is a sort of skylight at the end of it to guide the disoriented bee, so even though the passage is narrow the bee strives tenaciously headed toward the light. In doing so it rubs its body against the pollen sacs, called pollinia, which get glued to its back.
Once outside the bee flies away; its little brain can remember the unhappy experience long enough to travel some distance from the plant that it has just visited. But most likely, it will repeat this adventure when it finds another lady slipper some time later. At this point it will leave behind the pollinia that it has been carrying inadvertently, performing pollination of the lady slipper and getting no reward for its labor.

HUMMINGBIRD MOTHS. Where do they go in winter?

2009-12-06T06:06:00.001-08:00

Not all moths fly at night; some choose to do it during the day. One of them is the hummingbird moth, so called because it looks and flies and even hums like a diminutive version of a hummingbird when hovering in front of flowers. Just like their feathered namesakes hummingbird moths love long throated flowers, such as bee balm or horse mint. But unlike them, they don’t migrate south when the cold weather arrives. They resort to a different strategy to survive the harsh weather and lack of food.

Like all moths and butterflies they have a complex life cycle with dramatic transformations, called metamorphosis. The distinctive stages are called egg, larva or caterpillar, pupa and adult or imago. The one you are most familiar with is the adult, that colorful flying marvel; the other stages are wingless and prefer to remain out of sight and out of danger. The larva’s job is to eat almost non-stop and to grow; the pupa goes through a resting period and later through a tremendous remodeling job where all the parts are transformed to turn into the active, winged creature which we see during the summer. The flying adult’s whole purpose is to find a mate and to start the next generation; for that they need nourishment, nectar, which they find in flowers.

It is in the resting state of pupa that they choose to spend the winter. After the caterpillar reaches full size feeding on any of its favorite plants, such as hawthorn, black cherry or wild rose, it drops to the ground. There it spins a loose cocoon that lies partially buried under the leaf litter. Leaf litter is very important to this species; it provides some protection against the winter weather and against predators. When birds or squirrels go through leaf litter, scattering it here and there, they may very well be looking for one of these nutritious morsels.

If the pupa survives these attacks, it will complete its metamorphosis and emerge as a winged adult next spring, when nectar-laden flowers are blooming again.

POLLINATORS IN WINTER. Fritillaries

2009-11-30T10:43:00.001-08:00

Where do pollinators go in winter? When all the flowers that pollinators feed on are gone and when the cold grips the land, what do the pollinators do? They have to find refuges and hanker down until the next season. There are many different strategies at their disposal, many sheltered places, many options as to spend the winter months as eggs, larvae, pupae or adult. But they all make themselves invisible for several months of the year, hoping that no predator or parasite gets to them and hoping that the next season be bountiful and take care of their needs.
Here is just one example of a wintering pollinator, a pretty butterfly that you may see flitting around the garden during summer months: a fritillary butterfly.

Adult fritillaries are colorful butterflies of orange and black patterns, often mistaken for monarchs. Their long tongues enable them to reach for nectar hidden in long throated flowers such as horse mints, however they are not about to pass out a good opportunity to drink nectar from more accessible blossoms. You may start seeing them as early as May; by October they will be mostly gone or will look rather worn out, missing wing scales or even a piece of wing where a hungry bird took a stab and missed the body.
In late summer and early fall the females start looking for places to lay their eggs. Their babies feed exclusively on violets, so they need to find these plants and lay their eggs nearby. But by this time of the year violets are drying up or they are all but gone; only the roots remain under ground in many cases. This does not deter the egg laying females; either they have a formidable sense of smell that enables them to detect the roots of violets, or, in some cases, they just take a chance scattering their eggs on the leaf litter in shady places that are most likely to grow violets. In this case, some eggs will be lost, but there will be plenty left which will find their target.

The eggs are no bigger than a period at the end of this sentence; the caterpillar that emerges from it shortly afterward is about the size of a comma. Packaged inside this tiny body is all the genetic information needed to make all the colors and the beauty that will visit your garden fluttering from flower to flower during the warm months. There is no food for this baby during the winter months. So what is there to do? It promptly buries itself in the leaf litter seeking safety from the many small predators and parasites that hunt it in that dark and mysterious world that is the soil of your garden. There, it has nothing to do for several long, cold months; so it goes to sleep.

Probably many, perhaps most won’t make it through the winter; but the mother had laid so many eggs that there will still be plenty to keep the species going. By the end of winter it will be aroused, by some unknown cues. By then, violet plants are beginning to grow. Long before they start blooming, this caterpillar goes to work, feeding and growing for a couple of months. It will eventually emerge as a fully grown butterfly.

More on fritillaries life cycle in:
Pollinators welcome blog
Pollinator of the month

Only friends welcome here

2009-11-17T16:10:00.000-08:00

The wildflower Beardtongue or Penstemon gets its name from the hairy area that runs along the floor of its "mouth" looking like a bearded tongue. It is one of those flowers designed just for bumblebees. The size fits them like a glove; the length of its throat, where nectar is stored, is just right for the length of a bumblebee's tongue and the sexual parts of the flower are arranged so they rub the pollen against the back of the visiting bees so they carry it to the next flower.

But when it comes to other insect visitors they are not so welcoming. The outside of the flower is coated by glandular hairs, with shiny droplets of a gooey fluid at their tips. They feel sticky to the touch and, to a small insect, they are a death trap from which they can't disentangle themselves. I assume that they do it for protection although I can't imagine what protection they need from midges and the like.

Here you have one performing both functions at the same time, a welcoming host and a killer all at once.

THE BIRDS AND THE BEES. The True Story

2009-11-12T09:11:00.000-08:00

When October comes along we stock up on bird seed for the winter and try to make the right choices; some cheap brands are no good. A visit to the Cornell University Ornithology lab website would help us know what is best. Here we learn that some of the most common seeds are: sunflower, safflower, millet, cracked corn, peanut hearts, flax, sorghum and rape seed.

A house finch eating sunflower seed
Sunflower tops the list of preferred bird food because it is nutritious and rich in oils, badly needed by winter birds to generate the energy that keeps them warm. Some types of millets and flax are regarded as fillers and the Cornell lab doesn’t recommend them.

Woodpecker feasting on peanuts
The visitors to your bird feeder are wild animals that can survive on their own without your handouts. They are resourceful and can find wild foods through the winter; in fact many of them simply have no access to birdfeeders. They eat wild seeds similar to the ones you provide and berries of many sorts. If you are a birdwatcher you know that a good way to spot finches and other small birds in winter is to look at shrubs, preferably the ones laden with berries.

Let us examine these foods from a different angle. It is said that thirty percent of all the food that humans eat comes to them courtesy of pollinators primarily bees, what about bird food?

Long-horned bee pollinating a sunflower
Millet, corn and sorghum are cereals; the plants that produce them are wind pollinated. All the other bird seeds are from flowering plants that require the services of pollinators to produce seed. We are familiar with the flashy sunflowers and may have seen bees visiting them. Safflower is a type of thistle, also a blooming plant. Peanuts are members of the pea family with complicated flowers that require skilled pollinators to trip them and get to the pollen; these plants sometimes dispense with pollinators and simply fertilize themselves, but they produce more seed when pollinators are present. Rape is mustard, also dependent on pollinators. Finally, berries are dependent on pollinators.
So this is the true story of the birds and the bees.

Bees in the garden

2009-11-05T06:56:00.000-08:00

A bee house for mason bees. These bees are solitary, meaning that each one tends to her own brood, about six to eight babies, and all each one needs is a hole the size of a pencil in a block of wood. They do not live in large hives with thousands of workers like honey bees. You can get fancy and create a handsome bee house like the one my son in law did for me.

Watching the comings and goings of your little tenants can be almost as much fun as watching birds at your bird house, and there is no reason to fear their stings. Unlike honey bees they are very gentle; I have let them climb on my hand without problems. They emerge in early spring and are busy through April and May and, perhaps early June. You won't see more activity until next year. You can see the video.

This one emerged from its long winter sleep shortly before Easter, so I call it my Easter bunny bee.

Let us provide a habitat for some of the numerous helpers to our gardens, pollinators, a few tips provided by:
Urban Bee Gardens
Selecting Plants for Pollinators

You may also want to build nest boxes for those bees that make their homes in cavities.
There are instructions in several websites:
National Wildlife Federation
Audubon. Bring on the Bees.

Or you may choose to buy a bee house from one of the several companies that make them, such as:
Northwest Nature Shop
Mason Bee Homes
Knox Cellars
(I am not endorsing any one, just saving you some leg work or mouse work).

List of articles

OF BEES AND HONEY. What is honey for?

2009-10-10T07:24:00.000-07:00

Solitary bee, halictid or sweat bee, gathering food for her babies

In the beginning there were wasps, no bees at all. Wasps trapped bugs and used them to feed their babies who grew strong and healthy thanks to such rich protein food. Many adult wasps also visited flowers and fed on nectar, a rich octane fuel that gave them enough energy to do all that flying needed in their hunting for prey.
Once upon a time some little wasps discovered that the pollen that they had accidentally picked up and carried back home on their furry coat turned out to be very nutritious (also rich in proteins) so they switched to pollen and gave up chasing after bugs. One advantage of pollen is that it doesn’t run away nor fight back. They became hairier and developed baskets to carry pollen home, thus a new creature was born, different enough from wasps to belong in a different category: a vegetarian wasp, the mother of all bees.
Notice that I haven't mentioned honey yet. That came later. In those days all bees were solitary and short lived. The adults usually died at the end of the season. Only the next generation lived through the winter, feeding on its pollen reserves and sleeping quietly in a safe and secluded place, and in some cases covered by some sort of cocoon or cell.

Honey bee collecting pollen and nectar for the colony or hive, to feed her sisters and queen and store reserves for the winter

Finally some bees developed societies that lasted several years and had queens and workers and drones and members of the next generation, all living together in a large colony. In order to survive the winter they needed to store supplies, mostly nectar (to keep burning fuel through the winter and stay warm) and also some pollen. But the nectar is very watery and would take a lot of room so they developed techniques to reduce its water content; mostly they spit it out in a big bubble and swallow it back again and again until it becomes concentrated through evaporation and can be stored in cells. Yes, that is what honey is; maybe you lost your appetite for it. But, wait, it gets worse, sometimes when there is a shortage of nectar bees collect secretions from aphids and use those to make honey.
So, only social bees make any significant amount of honey and it is mostly for adult consumption. The domestic bee and a few relatives from Asia belong to this category and also several kinds of stingless bees from Central America and tropical South America. Bumblebees are also social. They live for a few months and make some honey but not much.
Interestingly there are a few kinds of paper wasps from Central and South America that are also colonial and that may live longer than a year. They also make honey, but this is very unusual for a wasp
Oh, yes, there are also some ants that make honey and have a very peculiar way of storing it. Some individuals, called "repletes" eat enormous amounts of honey until their bellies are perhaps ten times larger than normal. They hang from the ceilings of some chambers inside the anthill and serve as "honey pots" always ready to vomit and pass some of this material to their nest mates. I understand that the natives don’t hesitate to eat this sweet treat when they find it.

A Busy Pollinator and a Relaxed One

2009-10-08T14:23:00.000-07:00

An industrious little bee gathering food for her babies and pollinating flowers along the way. It methodically collects pollen without missing any and then promptly flies to the next flower.

The bee is very industrious and visits many flowers in a very short time. The flower fly, on the other hand, takes its precious time gobbling up pollen, so it visits fewer flowers overall.

BUMBLEBEES. Are Some Bumblebees Going the Way of the Dodo?

2009-09-28T10:49:00.000-07:00

Who doesn't like a bumblebee? With their plump, fuzzy bodies and striking black and yellow or black and white stripes they easily capture people's hearts, especially when they are seen buzzing around from flower to flower.

What most people don't know is that some species of bumblebees are in decline. We have heard about the plight of its relative, the domestic honey bee; but haven't paid much attention to the situation of this wild cousin. Why should we care? It isn't just because bumblebees are charismatic, but also, and more importantly, because they play key roles in certain ecosystems. So far, we know of only a few species that are showing a reduction in numbers, both in North America and in Europe. It isn't as if all the species of bumblebees were going extinct overnight; fortunately some species are doing well, even in unexpected places such as suburban gardens. But, perhaps we should start paying attention to what is happening now rather than when it is too late. Besides, it is possible that many other species of wild bees are suffering similar declines in their numbers and we have no way to estimate what is happening because we know so little about them.

Here are some of the things that bumblebees do: they pollinate 15% of our food crops, worth about 3 billion dollars; they also pollinate countless wild flowers. Wildflowers are important not just for their beauty, but also for the seeds and berries that they produce. They become food for many species of wildlife, from birds and small rodents to large animals such as bears. Birds don't know what percentage of their food crops are pollinated by bumblebees, but it is possible that for some species is closer to 90% than to 15%. If we are not worried about our own food, we should worry about all the many species of birds and other wildlife that may be suffering because of a reduction on the numbers of wild bumblebees.

Goldfinches and many others owe their food to hard working pollinators such as bumblebees.

The Life of a Flower

2009-09-26T18:40:00.000-07:00

Let us take a simple flower, the simplest you can think of, the one you drew when in Kindergarten. A yellow circle surrounded by petals. It looks like a daisy or a sunflower or an aster or a number of flowers with petals arranged like sun rays and a circle or disk at the center. Well, there is a surprise here; such a flower is far from simple. It has a very complex structure, in fact it isn't just a flower but a whole bunch of tiny flowers. Look at the little parts that comprise that yellow center. What a surprise! Each one looks like a tiny flower all by itself: five petals and a center with little things inside that resemble the center of many other flowers that you have observed at various times. Well, that is exactly what they are. Each one is a flower, called a floret; they are all clustered together.

Each floret contains all the parts of a flower, petals, anthers, stigma.

You may wonder about the petals that surround this cluster of flowers. Here is the answer: there are two kinds of flowers in this interesting bouquet; only the ones that make the outside rim have petals, the large petals that we see. They are called ray flowers while the ones in the center are called disk flowers. It would be nice if all technical jargon were as obvious as this.
In a newly opened sunflower or helenium, the disk flowers are just like little knobs. The next day the outer line of disk flowers has opened and you can see the sex parts, the pollen and seed producing parts, sticking out. Afterward, each day or so a new row of flowers open. The old ones begin to wilt; they look open and a little dry. Eventually one smaller circle after another opens and passes its prime.
Now let us observe the pollinators that come and visit the flower. They go directly to the freshly opened florets. They have nothing to do with the unopened ones, nor with the wilted ones. They find pollen and nectar only there and they know it. All this goes according to the plans of the flower; this works just right to ensure pollination.

One interesting thing is to look at the older flowers that have completed their cycle. The ray petals stay fresh and bright for a few days longer although that flower is no good to pollinators any more and it doesn't need visitors either; right now it is busy growing the seeds that will mature later on.
You may wonder why it continues to look attractive to pollinators. The reason is that a large clump of flowers is more likely to attract pollinators that are passing by than a smaller clump, with many dry blossoms in between. It is like you going shopping; a mall where many stores are closed or vacant is likely to drive you away rather than attract you. Once there, you aim for the store that interests you. Pollinators do the same; they notice the larger displays of flowers than the smaller ones, with the certainty that they will find some food there.

Helenium. The flower on the left is a young one, only a few florets opened. The one at right is older, most florets are past their prime.

Such flowers are skilled engineers, and good marketers. They know their clients and how to satisfy their demands, and they get good returns. Other flowers are arranged differently; they use different attractants; their timing varies; but they all know how to maintain a successful partnership with their pollinators.

The clients, on the other hand, know how to use this resource. You can see a bee visiting methodically all the florets and probing them with its long articulated tongue in this video

List of articles

BUGS IN THE GARDEN. Hornworm: Friend or Foe? Friend and Foe

2009-09-20T17:34:00.000-07:00

Do you grow tomato plants? Who is your worst enemy in that case? Probably the tomato hornworm or the tobacco hornworm. Those fat green caterpillars with a funny looking horn at the rear end, red in the case of tobacco hornworms, blue in tomato hornworms. Besides that minor difference they look very similar; they both attack your precious plants with gusto and grow healthy and vigorous in such a diet. They also feed on tobacco, potato, peppers and other plants of the Nightshade family.

The moths that emerge from those caterpillars after they are done growing and after a period of rest called pupation are called hawk moths or sphinx moths. They are very beautiful, mostly brown and white with orange markings on the sides of their bodies, five in the tomato hornworm and six in the tobacco one; once again not a big difference.

Naturally you hate the worms, fear to find and infestation of them in your garden and would like to exterminate them forever. Fortunately, Nature has provided a few enemies of hornworms that help you in your battle for control but you are very likely not to know them and even accidentally eliminate your little helpers in an effort to combat the worms. So, it is important to know both.

Occasionally you find a hornworm all covered with white little oval things that you might mistake for eggs. Those are not eggs at all; they are your friends. It is fascinating to learn how they got there, although I must warn you: be prepared for some gore.

There is a tiny wasp, so small that if you drop a handful of them on a white piece of paper they look like the marks you could make with a regular pen, no bigger than some scribbles. This wasp lays its eggs inside the body of a caterpillar. The poor thing feels the prick and goes back to eating and growing for a while, without knowing that it is doomed. Eventually it becomes lethargic and later catatonic. It stops moving but continues to cling to the stem of one of your tomato plants.

In the interim the wasp’s eggs have turned into minute grubs that start doing a lot of eating and growing of their own at the expense of the caterpillar. When they are fully grown, something out of the movie “Alien” takes place. Remember a scene, early in the movie? An astronaut, that had suffered an encounter with the alien creature, seems fully recovered. Then, all of the sudden, he screams and writhes in pain. A blood covered hideous creature, a parasite, the alien in question, bursts out of his chest and scurries away. They must have gotten the idea from the parasitic wasp.

The full grown grubs emerge from the body of the caterpillar after making little holes. They cling to the body for safety, and spin cocoons around themselves. By then the caterpillar is too far gone to care. The wasp’s larvae need a period of repose inside their cocoons to turn into winged adults. They emerge in a few days ready to go and infest another caterpillar. I told you that it wasn’t pretty!

But it works to your benefit. Be thankful to the wasps that keep the population of hornworms down and prevent serious damage to your tomato plants. Hold the pesticides! You don’t want to kill these friends of yours along with your enemies.

There is still another twist to this story. As I said, the unwanted pest that devours your plants turns into a handsome moth. The transformation is so complete that people even end up calling it by a different name; in the case of the tobacco hornworm it becomes the Carolina sphinx moth. It flies at night visiting flowers such as morning glories, sweet potatoes, Nicotiana, etc. in search of nectar. It hovers on front of them, unfurls its long tongue and drinks deeply. In doing so it pollinates them. It has gone from foe to friend, from tomato destroyer to pollinator. We have to think twice about our desire to eliminate the hornworm entirely. Perhaps Nature works best by keeping a delicate balance by means of parasites.

THE WEB OF LIFE. The Bear, the Waxwing and the Bee

2009-09-17T13:06:00.000-07:00

You may be wondering what bears, waxwings and bees have in common. We'll get to that later.

Let us start with a black bear, the formidable resident of forests and broad spaces. An encounter with one of them can be an unforgettable experience. It is surprising to realize that an animal built up with such powerful claws and jaws is seldom a hunter; in fact perhaps only 10 or 15 percent of its diet consists of animal matter and a good part of that is carrion or insects. So, what does a bear eat? With great versatility it finds a wide range of plant food in the course of the year. In early spring, fresh out of hibernation it may find skunk cabbage to its liking as well as sprouts from plants in the pea family, horsetails and sedges. Later in the season it will find the growing cow parsnips and dandelions, as well as flowers of several kinds. It may supplement this vegetarian diet with some animal protein, from caterpillars to the occasional newborn elk; but still about 80 percent of the summer diet is vegetable. In the fall, it is the time to feast on berries; blueberries, raspberries and everything in between. It can devour enormous quantities of this food because it needs to fatten for the long winter ahead. It is hard to believe that such diet can become many pounds of fat in the short period of a couple of months.

And now for cedar waxwings, those attractive birds that are so much fun to watch. They are especially interesting when they are engaging in their peculiar tradition of passing berries from one to another. Cedar waxwings eat an assortment of berries through the year. In summer, when they are raising young, they enrich their diet with insects; but berries are the main staple of their diet.

Finally, let us talk about bees. Let us make it clear that I am not referring to the domestic honeybee but to any of the numerous native bees and bumblebees that feed on pollen and nectar of wild flowers. If we want to be more specific we can choose the blueberry bee. This industrious little bee is very specialized on the pollen it chooses to feed her family. It goes almost exclusively to blueberry flowers. When doing so it carries some pollen from flower to flower and from plant to plant, providing the plant an invaluable service, pollination. Once the flowers are pollinated they can start setting seeds and developing fruits.

Now, you see the link between bees and birds such as the cedar waxwing and larger animals such as the black bear. They feed on the berries that have been pollinated by the bees or, in the case of the bear, on other plant parts that also require pollination to multiply.

Experts on pollination remind us frequently that one third of our food comes to us courtesy of pollinators; most fruits and vegetables require the services of these little go-betweens, most of them bees. What they forget to mention is the large number of other species that also depend on pollinators for a good part of their diet. The bear and the waxwing are just two examples of a very long list that intertwines the little bees with the more visible birds and mammals.

Another twist in this intricate web, the bear and the waxwing digest the berries but not the seeds. So they end up dropping them farther from the mother plant and surrounded with an amount of excellent fertilizer. So, the pollinator, in turn, also depends on the seed dispersers.

But the final, and perhaps most marvelous twist, is that the plants, so dependent on pollinators and seed dispersers are actually making use of them. They are very skilled in attracting their attention and supplying their needs, either with rich pollen and nectar or with juicy, nutritious fruits. At the same time, they make sure that not all the pollen gets eaten and that the seeds can safely go through the intestines of the berry gluttons.
Thus the web is complete: flowering plants need the pollinators and the seed dispersers; bees need the flowers and the seed dispersers and, finally, bears and birds need the plants and the pollinators. When you walk through the woods or the meadows, think about this invisible web and what it is doing to make everything possible.

Bear feeding: BearDiet

Cedar waxwing feeding: Appalachian Mountain Club: Bird of a Feather...

Metallic green bee, a good pollinator

2009-08-30T12:39:00.000-07:00

The pure golden green bee, Augochlora pura, is a singular bee, smaller than a honey bee and looking like a shiny metallic little robot bee. There are several other metallic green bees related to this, they compete in beauty and they are all good pollinators of many wild flowers.

In the spring she builds her nest under the bark of rotten logs. If you thought that dead trees or large dead branches had no use you were wrong. To this very nice pollinator they are prized real estate, just the right place to raise her family safely and well protected. She searches for the right dead tree diligently and, if your garden is one of those perfectly manicure ones, you will not have the pleasure of her and her family's company.

She builds a small chamber in the space between the loose bark and the solid wood using her own saliva and secretions. She packs it with a storage of pollen and nectar very carefully kneaded and shaped as tiny loaves. She encrusts the inner walls of the chamber with these loaves arranged like tiles. When she has enough to feed one baby from birth to maturity she lays a small egg and shuts the chamber. She surrounds it with loose debris which abounds in such places and starts the construction of other chambers. You may find a couple of rows of four or five of these cells. The mother bee dies at the end of the summer and the new generation spends the rest of the year comfortable and safe until the next spring.

FLOWER FLIES. Very Good Friends of the Gardener

2009-08-25T15:06:00.000-07:00

There are some little flies that visit flowers with great frequency. Naturally, they are called flower flies; although the British prefer the name "hover flies", which describes their behavior very accurately. They are very numerous in the garden; but if you dislike house flies you don't need to worry about flower flies; they are rather pretty. You probably didn't notice their presence thinking that they were bees, rather than flies.They are excellent impersonators of stinging insects such as bees and wasps and they probably fool hungry birds into thinking that they may get stung but these little "bees". This strategy seems to work very well for them, so they can go feeding on flowers unmolested by these winged predators.

Sphaerophoria

In their visits to flowers they accomplish some pollination. They may not be as efficient as bees, but their sheer abundance makes them important pollinators of wild flowers. But there is something else that these flies do that makes them very welcome in the garden: The larvae of some of them feed on aphids.

This is such an important task that they deserve more attention than they get from plant lovers. We don't appreciate them enough.

Partners and robbers

2009-08-24T06:51:00.000-07:00

A jewelweed blossom is worth examining carefully; it is a little marvel of engineering, with a shape perfectly adapted to its pollinator, a plump bumblebee with a very long tongue and a thirst for nectar.

The shape of the little sac fits the body of the bumblebee like a glove; the side petals open like a pair of curtains to allow its entrance; the length of its spur, full of nectar is just right for the tongue of the bumblebee. And, finally and most important to the plant, the anthers (that carry the pollen) and the stigma (which receives the pollen) are placed so that the hairy back of the bumblebee rubs against them when entering the flower. The pollen is deposited on the bee and later on it is transported to other flowers.

For pollination to take place the bee has to enter the front of the flower otherwise it would fail to touch the parts of the flower that matter.

Despite this marvelous system, some very nice pollinators can turn into robbers and cheat the flowers that they usually serve diligently. This happens when the pollinator chooses to take a shortcut and bypass the well planned scheme of the flower. Such is the case of this bumblebee. When it takes nectar by slashing the spur from the outside it doesn't come near the pollen carrying organs and doesn't perform pollination.

National Pollinator Week

2009-08-24T06:25:00.000-07:00

Pollinators are responsible for one third of the food we eat. Most fruits and vegetables have to be pollinated so that they can produce seeds. Also coffee, tea and chocolate need the services of pollinators.

We are so dependent on pollinators that we celebrate them once a year in National Pollinator Week, the last week of June.