An Upside Down Butterfly

Our beautiful sourwood trees (named for the sour oxalic acid in the leaves) are in bloom and they have a myriad of tiny white bell-shaped flowers that hang down. If these flowers remind you of blueberries, you are correct since both are in the heath family. Sourwood is generally pollinated by bees which are attracted to the very sweet nectar, which is made into one of the world’s premium honeys by European honeybees.

In our yard I noticed that the red spotted purple butterflies figured out a way to share in the rich nectar supplied by these tiny white flowers. They hang upside down, which is an awkward position for them, but it seems to work. So a behavioral trick allows these “upsy daisy” butterflies to steal some nectar meant for bees. It shows how the co-evolution of flowers and their designated insect pollinators can be disrupted by a trick. It also illustrates that butterflies are capable of learning how to extract nectar from a variety of flowers for which their body structure is not well adapted.

Bill Dunson

About Bill Dunson

Bill Dunson, born in rural Georgia, skipped 12th grade and went directly to Yale. Bill subsequent-ly received a PhD in Zoology from the University of Michigan, studying softshell turtles. Bill is Professor Emeritus of Pennsylvania State University thanks to a career spent entirely at that institution, teaching and doing research on the physio-logical ecology and ecotoxiciology of reptiles, amphibians and fish. Always curious about nature, Bill has dedicated his life to learning and sharing his knowledge with others. He has served on many advisory boards here in Southwest Florida to preserve the water that gives life to our region.

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