By Mary Shane

For The Vidette

In the summer, I find clusters of flies in our garage, flying and flying and flying. They never land. I call them “garage flies,” but my curiosity got the best of me not long ago, so I Googled information about them. As I learned while writing this article, they are called “lesser house flies,” and are a member of the scientific order Dipetera (which means “two wings”).

There are two other flies I have wondered about as well. One is the fly that buzzes nonstop—the one I always chase down because I can’t stand the noise. The third is the fly that bites me in the garden when I am weeding, leaving large itchy welts.

Here’s a brief rundown of these three critters:

Lesser house fly — It is the male of this species that flies endlessly around my garage. The females are less active and tend to stay near their breeding areas. They are indeed a “lesser” fly: about two-thirds the size of a house fly. Their circular flight is often around a down-hanging object such as a ceiling light. They rest at night either on tree branches or, inside, on walls or lamps. The lesser house fly is more reluctant to enter homes, liking instead to congregate in entryways, patios and — yes — garages.

The lesser house fly spends less time resting than does the house fly, and they seldom land on human foods. Hence, they are not as likely to transmit disease. They are, however, prolific breeders, particularly in chicken coops.

Horse fly/deer fly — These two pests are similar, though the horse fly is about 1 inch long, and the deer fly is close to a half-inch long. Horse flies are mostly dark brown or black and look shiny. It is the deer fly that bites me in the garden; it is the smaller of the two.

Only the female deer fly feeds on blood, biting a cross-shaped incision into skin. While feeding, an anticoagulant is injected into the wound, increasing blood flow. The males feed on pollen and nectar. This fly is found in woodlands and wetlands, where eggs are laid on leaves above a watery surface. A few days after hatching, the larvae travel to the water to begin feeding.

Both deer and horse flies are capable of transmitting Tularemia to humans through their bite. About 200 cases are documented each year across the United States, though not all from these flies. Handling infected rabbits and tick bites can also cause this disease.

House fly — This bad boy/bad girl is the pest that I track down with a swatter whenever it is buzzing through the house. The noise comes from house flies rubbing their wings together during flight, about 190 times per second. These non-biting flies are well worth smacking because they can carry viruses, bacteria and parasites. House flies live for about two weeks. Females lay up 100 eggs at a time, or about 500 eggs through their short lifetime. From egg to adult fly takes about 10 days.

I learned while writing this article that some entomologists distinguish in their spelling between true flies and flies that are not a member of the Diptera order. The names of the true flies are written in two words, like you see here in this article, while other “flies” are spelled as one word: butterflies and dragonflies, for example.

Mary Shane, a Master Gardener since 1998, lives in the Val Vista neighborhood west of Montesano.