Pollinators: flower

Showing posts with label flower. Show all posts

Sunday, April 24, 2016

The flower reinvented

Dichromena latifolia or Rhynchospora latifolia, identified by Andrew Greller.

Sedges and grasses are wind pollinated and have no showy flowers. It is interesting that Narrow-Leaf White-topped Sedge evolved to attract pollinators and created a sort of flower for this purpose. The apparent petals are not the same as those of a real flower but modified leaves called bracts.

See: Plant Profiles. White Top Sedge

List of articles
Beginners Guide to Pollinators and Other Flower Visitors

© Beatriz Moisset. 2016

Wednesday, March 18, 2015

Mass Appeal and Pollination

Some of the many visitors to goldenrod. © Beatriz Moisset

Many flowers are not particularly selective; they welcome all kinds of visitors. They are wide open, easily accessible, thus many insects can reach the nectar and/or pollen regardless of whether their tongues are long or short. Such flowers provide a convenient standing platform to save their visitors the inconvenience of hovering over them. Their structure is simple so the pollinators don’t need to figure out how to open them in order to reach their rewards. Goldenrod is a fine example.

Monarch butterfly on goldenrod. © Beatriz Moisset

I have spent countless happy hours observing goldenrods and photographing their numerous visitors. The one most common in my area is the Canada goldenrod. Several hundreds of species visit their flowers. Bear in mind that not all flower visitors qualify as pollinators. Some are not efficient at carrying pollen, or sit in one place for a long time and never make it to another plant. Such is the case of ambush bugs, whose only concern is to snare hapless pollinators to make a meal out of them. If you are interested on photographing and identifying pollinators this is a good place to start.

Metallic green bee. © Beatriz Moisset

This plant blooms in the fall. It often gets blamed for allergies, but the real culprit is another plant that grows close by, sometimes intermingled with goldenrods, ragweed. Its flowers are inconspicuous because its pollen gets carried by the wind, not by officious pollinators. This is how it gets into our nostrils and causes our suffering. The much maligned goldenrods have larger, heavier and stickier grains of pollen that cannot get airborne and that require help from visitors.

Two states, Kentucky and Nebraska, have the goldenrod as their state flower. It is not clear which species of goldenrod Kentucky picked, but it is likely the Canada goldenrod (Solidago altissima). Nebraska’s choice is clearer, the giant goldenrod (Solidago gigantea). South Carolina, not satisfied with a state flower, also has a state wildflower. It is the Canada goldenrod. It is worth mentioning that Delaware has a state herb, the anise-scented or sweet goldenrod (Solidago odora).

Bumble bee on sunflower. © Beatriz Moisset

Coreopsis. © Beatriz Moisset

Two other state flowers also have mass appeal. Like goldenrod, they are members of the daisy or aster family, easy to access by different kinds of visitors. They are Kansas’ sunflower (Helianthus annuus) and Maryland’s Black-eyed Susan (Rudbeckia hirta). It is worth mentioning here that two states, Florida and Mississippi, chose the tickseed (Coreopsis spp.) as a state wildflower in addition to their official state flowers, the orange blossom and the magnolia, respectively.

Kentucky: Goldenrod

Nebraska: Goldenrod

South Carolina (wildflower): Goldenrod

Delaware (herb): Goldenrod

Kansas: Sunflower

Maryland: Black-eyed Susan

Florida (wildflower): Coreopsis

Mississippi (wildflower): Coreopsis

The indiscriminate pollination strategy represented by all these flowers has advantages and also disadvantages. They suffer no shortage of pollinators. If one species is doing poorly one year, as it often happens in the insect world, there are plenty more to fill in the deficiency. However, sometimes too much of a good thing can be bad. Some of these non-specialized pollinators may be visiting a variety of flowers instead of being faithful to just one species so they end up carrying the wrong kind of pollen in such cases.

Blossoms with such mass appeal give me the opportunity to introduce the reader to the main groups of pollinators. They are all well represented on these mass appeal flowers.

Andrenidae bee © Beatriz Moisset

Bumble bee. © Beatriz Moisset

Let us start by getting acquainted with bees. More than 80 species have been seen on goldenrods. Some of them deserve mention. Bumble bees are larger than other bees, plump, dark with yellow or white stripes, and hairy. Metallic green bees are small and gorgeously colored. They may escape notice if one isn’t very observant; but it is easy to become captivated by their shiny aspect. Mason bees and leaf-cutting bees carry pollen on their underbelly, unlike most other bees that carry it on their hind legs. Most of them are dark, nearly black and about the size of honey bees or slightly smaller.

Wasp. © Beatriz Moisset

Wasps are related to bees and sometimes people confuse them. Most wasps are less hairy than bees and have narrow waists. They raise their young on a diet of insects or spiders, instead of pollen and nectar as bees do. Adult wasps need nectar to fuel their flight. Thus, they are frequent flower visitors and accomplish some pollination.

Syrphid fly. © Beatriz Moisset

Many types of flies, including mosquitoes and gnats visit flowers to feed on their nectar. Some are good pollinators. The Syrphid flies, also called flower flies, are among the most assiduous flower visitors. Most of them mimic bees or wasps and are frequently mistaken for them. However, they don’t sting and there is no reason to fear them.

Buckeye butterfly on goldenrod. © Beatriz Moisset

Pyrausta moth on sunflower. © Beatriz Moisset

Yellow collared scape moth on goldenrod. © Beatriz Moisset

Butterflies, skippers and moths have extremely long tongues that they can use like drinking straws when sipping nectar. They favor long necked flowers and carry pollen from one to another.

Polished lady beetle on sunflower. © Beatriz Moisset

Soldier beetle on goldenrod. © Beatriz Moisset

Finally, beetles, although not well specialized for pollination, are also capable of doing so in special circumstances. We already mentioned magnolia pollination by beetles. They also visit other flowers and can do a reasonably good job in some cases.

In the following chapters we’ll see flowers that have chosen a different strategy. They are pickier or more selective. Some attract a handful of visitors; a few go to the extreme of having relationships with only one species of pollinators.

Pollinators of Official State Flowers

References

Goldenrods and Asters: Great PollinatorPlants for the Fall. Penn State Extension

List of articles
Beginners Guide to Pollinators and Other Flower Visitors

© Beatriz Moisset. 2015

Monday, February 10, 2014

Alfalfa Pollination


Large commercial alfalfa field requiring managed beehives because of its size © Vapampidis. Wikicommons

What is the most important insect-pollinated crop? Not a fruit or a vegetable but alfalfa. Yes, alfalfa, not because we consume large amounts of their sprouts, but because cattle needs this food. Thus: no alfalfa, no beef or milk.

This crop was first introduced in California during the gold rush. Alfalfa farming grew from there at a steady pace to what it is today, the third largest crop, after corn and soy bean. A few species of bumble bees and solitary bees took a look at this exotic flower, found it to their liking and proceeded to pollinate it. It wasn't a big leap; this plant's blossoms resemble those of other members of the pea or bean family. The native pollinators were familiar with bean flowers and adapted easily to the new arrival.

Alfalfa blossom. H. © Zel. Wikicommons

Peas, beans, alfalfa, clover and several other plants have butterfly-like (papilionaceous) flowers. The lower petals form an enclosure, shaped like the keel of a boat. This structure holds the sexual parts, the anthers and pistil. When an insect lands on the flower, a trigger mechanism makes it snap open or trip the flower. This is how pollination is accomplished.

Honey bees were not present in California when the earliest fields of alfalfa were cultivated. The first beehive arrived in 1853, just one solitary hive; a few others had died in transit. It took many years for the honey bee populations to build up to significant levels. This didn't matter because the wild bees did an excellent job.

New Zealand wasn't so lucky when it started growing alfalfa to feed the recently introduced cattle. The few native pollinators were stumped by the new flower. They lacked the necessary equipment and dismissed the strange blossoms. Year after year, hay grew luxuriantly, but no seeds. Alfalfa growers resorted to importing a few species of bumble bees from Europe to cut down the expenses of having to buy seed every year. Thus, industrious bumble bees saved the day in that country.

Scotch broom, a papilionaceous flower, being tripped. © Beatriz Moisset

Honey bees detest the rough treatment alfalfa flowers subject them to and soon learn a trick of their own. They enter the flower from the side and help themselves to nectar without tripping its mechanism. Only naïve, youthful ones pollinate flowers. Despite the honey bees' poor performance, most alfalfa farmers resort to them because of the convenience in using a managed species.

In addition to the honey bee, two other species of alfalfa pollinators are managed to some extent and used commercially. They are the Japanese alfalfa leafcutter bee and the native alkali bee.

The populations of native bees have been severely reduced in the last one hundred years largely because of intensive agriculture. Restoring their numbers and putting them to work in alfalfa fields would be an arduous task but a worthy one. Some farmers find that, when they include flowering and nesting site places in their fields or orchards, the health of the crop improves and the need for pesticides diminishes. Thus, alfalfa pollination could be done entirely and more efficiently by native bees. This form of agriculture would be more sustainable than the present methods.

List of articles
Bring Back the Native Pollinators
Will We all Die if Honey Bees Disappear?
Growing Insects: Farmers Can Help to Bring Back Pollinators
Organic Farming for Bees

Beginners Guide to Pollinators and Other Flower Visitors

Sunday, January 12, 2014

Beginners Guide to Pollinators

Read the review by Kathy Keatley Garvey at the Bug Squad website, For Beginners, a Guide to Pollinators

So many flowers. So many pollinators. So many floral visitors.
On every field trip, we see something new and different.
With so much interest in pollinators, it's good to see that biologist Beatriz Moisset has written a downloadable book, "A Beginners Guide to Pollinators and other Flower Visitors." It's meant for young adults and beginners.

Beginners Guide to Pollinators and other Flower Visitors available at:

Barnes & Noble
Lulu.com

iTunes
Amazon

Friday, June 7, 2013

A Sea of Blue Flowers

When Lewis and Clark parted in their expedition across the continent in 1804, many wonders awaited them. When crossing the Mississippi they left behind many familiar things and faced others totally unknown to European settlers.

A marvelous, astonishing sight west of the Rocky Mountains was a valley that looked like a blue sea with gentle waves rippling across it. A dense carpet of blue flowers stretched for miles deceiving the eye to the point of looking like a vast lake.

The flowers, unknown to them, were the camas lilies (Camassia quamash) of the west. They look like small lilies, although they are more closely related to the agave than to other lilies. Their nutritious bulbs provided an important food to the local peoples. Despite the laborious preparation to eliminate toxic components the Nez Perce and other tribes resorted to this food through the winter pounding it into flour and baking it into bread-like cakes. Lewis and Clark were happy to supplement their dwindling supplies by purchasing camas lilies cakes from the Nez Perce.

Most of the land of the camas lilies has been taken for cultivation of crops. We can only imagine the full glory of the blooming fields of two centuries ago when looking at the scattered small plots which represent their last remnants.

One of the familiar things the expedition members left behind was the honey bee or domesticated bee. There were no domestic bees west of the Mississippi in those days, only native ones. It would take another fifty years for some enterprising folks to carry beehives from the eastern United States to California. Only one hive survived the ordeal of such a trip. Many years passed before honey bees became established and significant beekeeping operations got underway.

Camas lilies were not deprived of pollinators. They had no need for honey bees; abundant insects made their living from gathering their pollen and nectar. When the new crops and agricultural methods including monocultures took over much of the land, the honey bee became the workhorse of crop pollination.

Where did the native pollinators go after the numbers of camas lilies shrank to insignificance? Probably we'll never know. We can guess that some found pollen and nectar elsewhere and survived, although their numbers, too, must have been reduced. We acknowledge the disappearance of a way of life and of the seas of blue flowers. The pollinators of centuries ago went about their job silently and unnoticed. Thus, we cannot appreciate their absence.

One Bite out of Three

List of Articles