Exoskeleton
In the course of my wanderings in the woods, fields and wetlands I encounter many natural objects that cause me to ask, what is that thing? Indeed these little puzzles provide a never ending source of wonder about the natural world and lead to searches in books and on the web to find answers. See how well you do in identifying these objects that I found this week.
Item A is a photo of a hole dug under a rock with some debris outside that appears to be remnants of a wasp nest. I interpret this to be the results of a skunk digging up a yellow jacket nest and eating the larvae. Skunks are famous for this and I can only marvel at their ability to survive the stings, although perhaps since they do this at night the ferocious yellow jackets are less terrible than they might be. I have come to have a new appreciation for the role of skunks in locating subterranean insect prey and their ability to keep the native yellow jackets in check. Unfortunately we now have exotic yellow jackets that build aerial nests.
Item B is a small pile of mud pellets built around a tube. This one seems to have been stepped on by a deer. These are always near water and are the upper end of the burrow of a crayfish. They are bioindicators of wetlands since the crustacean must have water at the bottom of the burrow to keep its gills wet.
Item C is an insect, but what sort? It appears to be a bumblebee, but look at the shape of the eyes, the feet, and a tiny whitish blob below the point where the single pair of wings meets the body (a haltere- found in flies as a sense organ to stabilize flight). So this is not a bee but an asilid fly that mimics a bee for protection against bird predation. The precision of this mimicry is absolutely amazing. When I noticed this very large fly sitting on a leaf next to the trail, I immediately thought that it must be a bumblebee, and it even buzzed loudly when it flew. Yet on closer inspection of the photograph it is clearly a fly. This illustrates how intently birds must examine potential prey, and how their choices of what to eat over eons has shaped the structure of the bugs that lived to breed.
Item D is obviously a large and very strange insect attracted to a porch light, but now sitting on my hand. This dobsonfly (in this case a male with very large jaws) is the adult stage of an aquatic larvae called a hellgrammite, well known to bass fishermen as a feisty but excellent bait. The life cycle of this species (a long lived aquatic larvae with a short and non-feeding adult phase) is interesting and cause for reflection since the only purpose of the adults is for sexual reproduction.
Item E is a side view of a spider that is trying to make itself inconspicuous while sitting on a leaf. In this case the spider’s yellow/orange color gave it away but this nursery web spider is usually brownish and blends well with the surroundings. It is a good mother and carefully tends a brood of spiderlings in a web constructed in vegetation. So we can see that the life of a small spider is strongly influenced by its need to escape visually oriented predators- likely birds.
Item F is clearly the head of a turtle, and in this case a box turtle. This turtle has “crazy red eyes” indicating that it is a male and I took this view while briefly interrupting its intense courtship of a female. It was biting at the head of the female while attempting to mount and mate with her. This is not an easy process for turtles due to their shell design and the male has only a small advantage with a slightly concave lower shell or plastron. As Ogden Nash has written: ” The turtle lives ‘twixt plated decks, Which practically conceal its sex, I think it clever of the turtle, In such a fix to be so fertile.”
What would life be without natural mysteries, and the fun of solving them?
Bill Dunson, Englewood, FL & Galax, VA
wdunson@comcast.net