Friday, January 13, 2006
Forms of flight in a tiny universe
I was recently moaning about the lack of syrphid flies buzzing around. It takes a lot of energy to fly when you're an insect so it follows in midwinter these flies either aren't around (they're over-wintering as pupae) or they don't have the energy to move their flight muscles. It's been warmer this week, though, and I saw this one pretty syrphid.
The ability to fly gives insects command of the sky and a great ability to disperse, exploit resources, and flee from their enemies. Only adult insects have wings: that and sexual maturity being the rewards of surviving immaturity. Survival involves eating enough and at times fleeing to keep from being eaten. But fleeing, when you are a fattening caterpillar focused on food, is a paradox.
A tactic used by looper caterpillars is spinning down, aka bungee jumping. This looper dangling off the strawflower escaped my notice until I was reviewing the syrphid fly photos. I guess her predator was fooled too. For all I know, I was the perceived predator blundering around with my fool camera pointed at that pesky flying thing.
Here's an article well worth reading about the mechanics of the looper caterpillar climbing back up the silk bungee cord after the danger of being eaten has passed.