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.

Be sure to visit the
DUNSON ARCHIVES
for many more facinating and educational notes and photographs from Bill.

The Tiny World of a Daisy

During my strolls through nature I often think about the different scales of events that we observe and marvel at. Sometimes these are large- perhaps looking at fall colors of a mountain or at the expansive sweep of a beach scene and ocean vistas. At other times the very small things attract our attention and wonder. This particular day there was an impressive display of daisy flowers which normally I would hardly notice since it is such a common scene. But something drew my attention to the creatures that occur on these flowers.

A remarkable variety of critters inhabit the daisy flower, perhaps as a convenient spot to sit, or to gain nectar or pollen, or to hunt for prey. One that drew my eye immediately was the brightly colored milkweed bug. This true bug (with sucking mouthparts) feeds on the poisonous milkweed, and like the monarch butterfly, gains some protection from this fact and advertises its toxicity to birds.

There were also a number of house flies on the daisy flowers. This could just be a suitable platform for them to rest or they may gain some nutrients from the flowers- I do not know. Most flies have mouthparts that suck up fluids.

A fly that is often found on flowers is the hover fly or flower fly. The one pictured is a mimic of a yellowjacket and thus is likely to gain some respect from potential predators due to its uncanny resemblance to a ferocious stinging wasp. Of course flower flies do not sting or even bite and thus the yellow and black colors are a deception. The large number of kinds of bee mimics indicates that this strategy is remarkably successful in deterring predators such as birds, which feed by sight and are susceptible to wasp stings.

However the failure of such a strategy against all predators is well illustrated by the photos of a crab spider which had captured a flower fly wasp mimic. Crab spiders have an ability to change color and match the background very well. I actually noticed the fly and began photographing it without at first seeing the spider. I then saw that the fly was dead and in the clutches of this amazing spider. Crab spiders sit in flowers and hunt without a web, grabbing their prey with their long front legs. They are remarkably strong and must have venom quite toxic to insects, as is shown here by the capture of a fly larger than the spider.

So take the opportunity on occasion to look down at the small things in nature and observe some amazing events. There is great beauty there and a complex world of predator and prey.


Bill Dunson
Englewood, FL & Galax, VA
wdunson@comcast.net

http://www.galaxgazette.com/blogs

http://lemonbayconservancy.org/wildflower.htm

Each month this page will feature one of Bill's facinating and educational nature notes.
Be sure to visit the DUNSON ARCHIVES for the ever growing collection of articles and photographs.