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Friday, February 24, 2006

A Few Stupid ?s about a Bug

Too bad I still don't know the species of this assassin bug (assumed to be genus Zelus, though), but nameless as they are, they have kept the predatory fires burning through the winter. There are more and more of them out hunting as spring progresses. This one is waiting for a meal on a cassia artemisioides bush. Zelus are general predators, so they will prey on a variety of insects. But surprisingly few insects visit this cassia even when it's in full bloom. Honeybees, a typical meal for an assassin bug, don't. I recently saw some female carpenter bees eagerly feeding on the cassia flowers; but these big black bees are many times the size of the would-be assassin. Pretty as this bug's home seems to me, is it actually kind of a Zelus blighted district, with a bugs' equivalent of failing schools and boarded-up shops?

So what makes a particular general predator bug take up residence where he does? If he hatched from an egg laid on that plant, and spent his hungry nymph-hood there one could imagine that a fondness, or at least familiarity would develop in the wee brain of the bug for the old home neighborhood. Then as long as enough prey presents itself the nymph and even the suddenly mobile adult would not be stimulated to leave the old home shrub. But, do strains of assassin bugs develop with special skills to better exploit the resources that visit the cassia? If an assassin bug from the queen anne's lace clan (if there is such a thing) was plucked from his umbelliferous perch and placed on a pea-like cassia, would he eat as well as a member of the native cassia clan (if there is such a thing)? Do general predator bugs have prey-specific abilities or attributes that tend to concentrate in a local population over generations, or do they have a toolkit of skills that are called on as needed by each individual bug, depending upon the environment or prey? Or are assassin bugs simply driven by instinct to wait; then pounce at whatever happens by; and starve in the waiting or die in the pouncing on prey too large or succeed in getting it right by chance?

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