Mickey Mouse Bugs

(This column was first published in the December 13, 1999 Buffalo News.)

    Mickey Mouse invaded our house once again.

    For the second year in a row we were briefly inundated with little insects less than a quarter inch long with wings that they held roof-like over their bodies to make them look exactly like Mickey Mouse ears.

    They first appeared in our basement. Doris is convinced that they entered through our drier exhaust. Soon they migrated to our kitchen and bathroom sinks, then spread out until we began to find a few of them crawling around floors, walls and windows. When they fly, they flutter rather moth-like following seemingly random flight plans.

    These little critters do not react quickly like houseflies so it was easy for me to edge a piece of white paper under one to pick it up and examine it more closely. Immediately apparent was how extremely hairy it was. It looked as though it was wearing a fur coat.

    My attention captured, I got out our old family microscope to see what it looked like under magnification. Wow! Hairy is hardly the word for this insect. Not only are its wings covered with hairs, but so too are its body, its legs and even its antennae. Just about its only hairless parts are its eyes.

    Those antennae I found especially interesting. They look like little shish kebabs each with a dozen tiny apples skewered along it. And each of those apple-like balls has its own dozen hairs sticking out from its sides like miniature hors d'oeuvre toothpicks.

    These little insects are not moths, as Doris and I had first expected from both their appearance and their erratic flight; instead they are flies. But given that resemblance they are called, quite reasonably, moth flies. They are also called drain flies because, indoors, they spend the egg and larval stages of their lives in the accumulated moist organic material that collects in drain traps, garbage disposals and other plumbing fixtures.

    These insects, although bothersome, are harmless and, thank goodness, they represented only a temporary nuisance. We rid ourselves of them both years by first applying a strong drain cleanser to our drains and then, the next day, pouring boiling water down them. That apparently prevents the next generation from developing. It helps too that the further decline in temperature ends the additional recruitment of colonizers from outside.

    An English entomologist has studied the important role these flies play in the sewage beds of Leeds. He found that their larvae attach themselves to gravel in the beds and assist the decomposition process by feeding on algae, fungi and their associated bacteria. When he flushed out these moth fly larvae by increasing the water flow to dislodge them from the pebbles, the sewage drains soon clogged up with organic material.

    He also determined that the larvae controlled their own population and that of associated insects and worms, becoming carnivorous -- and even cannibalistic -- when their numbers increased beyond carrying capacity.

    A positive feature of living in our colder climate -- this is only one of those pluses -- is the absence here of the biting sand flies of our southern states and the tropics that are closely related to moth flies. (Those sand flies are different, however, from the mayflies and caddisflies that bloom along our lakes and rivers and are often locally referred to by that name.) Some of those southern species cause severe asthma attacks and several tropical species spread leishmaniasis, a severe and chronic ulcerating skin disease.

    It is clearly far better to put up with a few days of Mickey Mouse bugs.-- Gerry Rising