When we watch insects and birds foraging on flowers we hardly give any thought to the motives of the beautiful relationship between the pollinator and the flower. However things are not always as they seem! Animals likely have only one thing in mind when they approach a flower- what they can get from it in terms of nectar and/or pollen. Flowers on the other hand require something entirely different; they need fertilization for their eggs/seeds, and distribution of their pollen to other flowers for cross pollination. In all such relationships there is no altruism involved, only evolutionary strategies that lead some plants and animals to develop intricate co-evolutionary relationships to increase the chances of fertilization and diminish the amount of cheating.
One of my favorite past-times is to watch a particular type of flower, observe the visitors, and try and figure out who the real pollinators are likely to be. Recently I came across a patch of short phlox in a pathway in our Virginia woods and observed two insects visiting the striking flowers. A sphinx or hummingbird moth was flying quickly up and down the path visiting many of the flowers while hovering. It extended a long tongue down the very narrow, extended corolla tube to where the nectar is found. This seemed likely to be a pollinator and I have shown a photo of a representative sphinx moth from our area. Yet large bumblebees were also visiting the same flowers but had an entirely different mode of operation. They landed on the flower, causing it to bow down, grasped the corolla tube and bit through it. I could even hear the cracking noise as their jaws pierced the nectar tube. Since the bee does not generally come into contact with the stamens, it does not likely pollinate the flower. Presumably the phlox gets little or no benefit from the visits of the bees so these hymenopterans can be considered parasites.
A very different situation is found in warmer locations where cape honeysuckles are grown. This plant originated in S. Africa and has beautiful red/orange blossoms that are quite attractive to birds and insects, but the flower tube is long, curved and fairly narrow. Thus migrating orchard orioles in our Florida yard pierce the base of the flower and drink the nectar. Most honeybees do the same thing- they bite through the base of the flower. In the photo you can see a number of bite marks; I occasionally see a honeybee attempt to crawl down the corolla tube but it seems to be very difficult for them due to the curvature. In its native land this long curved flower is apparently pollinated by sunbirds, which have a bill well suited for this purpose.
One of the great delights of late spring in the southern mountains is the blooming of the flame azaleas. A plant with yellowish blossoms I observed recently was being visited only by bee flies. These strange flies hover in front of blossoms and extend a very long proboscis or tongue down into it to gather the nectar. Could this tiny, fuzzy insect be a pollinator of this spectacular flower? Possibly, since the stamens are quite long and the style and stigma are even longer, making it probable that some pollen will be picked up and transferred between flowers.
So if you are a lover of flowers and of drama, you cannot fail to be amazed by the antics of the pollinators and nectar thieves that visit your favorite flowers. If you want a quick guide to the general types of insects that you may encounter, look at “Field Guide to Insects of North America” by Eaton and Kaufman.
Bill Dunson, Englewood, FL & Galax, VA