The Earliest Pollinators: Beetles and Flies

Magnolia © Beatriz Moisset

 By the time the first flowering plants appeared on Earth there weren’t any bees or butterflies. Those superb pollinators would take millions of years to evolve from wasps and moths respectively. So, who would be attracted to flowers? Who would carry pollen?

Other insects, although not adapted to sipping nectar and storing pollen in little baskets, liked to visit flowering plants to eat the pollen. Sometimes, they also devoured the flowers themselves. Beetles and flies were among the earliest pollinators. These two groups of insects visit the flowers of magnolia and water lilies to this day. In general, flowers pollinated by beetles are cup-shaped to allow these insects to stay for some time. They are strongly scented by fruity or rotten smell. The petals may be tough and leathery, helping them to put up with the abuse; many of them are greenish or creamy white.

Tumbling flower beetles on magnolia © Beatriz Moisset

The state flower of Louisiana and of Mississippi is the Magnolia (Magnolia grandiflora) which is an example of some of the oldest flowering plants; it presents all the qualities listed above and it is pollinated by beetles that use the flowers as a singles bar. They stay for hours eating, drinking, mating and making a mess of the place. When they arrive, usually only the female part of the flower is mature enough, so if they carry pollen from other flowers they get cross-pollinated, but by the time the beetles leave, the stamens or male parts have become ripe. The visitors get easily dusted with it and ready to carry it to the next awaiting singles bar. Beetles and flies find a coating of nectar covering the petals that they can slurp as they go along.

Dance fly on Magnolia © Beatriz Moisset

It is worth mentioning here the tulip tree (Liriodendron tulipifera) because it is the state tree of Indiana, Kentucky and Tennessee. The state flowers of Indiana and Tennessee are not native; they are the peony and iris, respectively, so I like to think of the tulip tree blossom as the honorary state flower of these two states. The tulip tree is a relative of magnolias, equally ancient; its flower bears some resemblance to magnolias. It is also pollinated by beetles, although bees and other insects also contribute to its pollination.

Another ancient flower, the California poppy (Eschscholzia californica), California’s state flower is also pollinated by beetles in some instances. These are more numerous than bees in arid areas. Several species of bees, including honey bees also pollinate these flowers.

California poppy © Audrey. Flickr

State flowers that illustrate the earliest pollinators:
Louisiana: Magnolia

Mississippi: Magnolia

California: California Poppy

Once plants came up with this novel solution to their fertilization process, there was no stopping them. Evolution accelerated and an ever growing variety of flowering plants emerged from the older lineages. In turn, more insects evolved to take advantage of this resource. This is how some carnivorous wasps went vegetarian. They became what we now know as bees. Pollen and nectar supplied all their needs.

Also some moths developed a taste for nectar during their adult life. Unlike most moths, they were diurnal and often sported fancy colors. In other words, they evolved into butterflies. Being frequent flower visitors they became pollinators. This is not to say that wasps and moths, the predecessors of bees and butterflies don’t pollinate. In fact some of them are valuable and are highly specialized ones.

The following posts deal with these pollinators and their flowers.  We will start with the ones who invite a wide assortment of guests. They have mass appeal and several state flowers illustrate this nicely.

Pollinators of Official State Flowers 
Mass Appeal and Pollination

List of articles
Beginners Guide to Pollinators and Other Flower Visitors

© Beatriz Moisset. 2015

Pine Barrens, Plants and their Pollinators

Pine tree shedding pollen

The Pine Barrens of New Jersey is well worth a visit. The Pinelands Preservation Alliance is dedicated to preserve this unique treasure. Let us take a look at some of the pollinators of its plant community.

The 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 employ the services of pollinators invest some of their energy in producing flowers that attract and recompense the visitors. This investment is compensated by the reduced need to produce large amounts of pollen. Flowers have an array of different techniques to accomplish this. 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 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 orchid known as 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 find 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 of orchids; but shortly afterward, it will be quite willing to repeat the experience because its little brain will have forgotten all about it.

Magnolias and Beetle Pollination
Lady slipper

Beginners Guide to Pollinators and Other Flower Visitors

List of articles

© Beatriz Moisset. 2012

Magnolias and Beetle Pollination

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 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 blooms are past their prime and are not receptive for pollination. So it is the beetles that carry the lion's share of the responsibility for perpetuating these plants.

Beginners Guide to Pollinators and Other Flower Visitors

List of articles

© Beatriz Moisset. 2012