What is a fly?
Flies are insects of the order ‘Diptera’ and have a single pair of wings. Of the many types of flies, the three most encountered by American Pest are:
Blow Fly or Bottle Fly
Adults are about 1/8-5/8 of an inch (4-16 mm) long, the size of a house fly, or slightly larger. Mature larvae are about 3/8-7/8 of an inch (9-22 mm) long. They have sponging mouthparts; antennae are feathery, at least on the bottom two thirds. Larvae are eyeless, legless, tapered from large, rounded rear segment to head, which is a pair of dark hooks. Adults are partly or wholly metallic blue, green, or dull brassy, sometimes black. Larvae are pale yellow to white.
Small fruit fly and vinegar fly adults are about 1/8 of an inch (3-4 mm) long, including wings. Adult small fruit flies have antenna with a feathery bristle; wings with thickened front margins, intersected in two places. Mature larvae are about 1/4-3/8 of an inch (7-8 mm) long, eyeless, legless and tapered from large rounded rear to the pair of dark mouth hooks at the “head” end. Adults are dull tan to brownish yellow or brownish black; eyes usually bright red. Larvae are nearly white, except mouth hooks which are black and the tips of the abdominal breathing pores which are yellowish.
House fly adult is about 1/8-1/4 of an inch (4-7.5 mm) long, female larger than male. Mature larva is about 1/4-3/8 of an inch long (7-10mm). Adult face has 2 velvety strips, silver above and gold below; thorax has 4 narrow stripes; no pale spot behind head or rear tip of thorax; sides of abdomen usually pale; sponging mouth parts. Larva is eyeless, legless, tapered from rear to head, which is a pair of dark hooks. Adult is dull gray. Larva is cream colored and greasy looking.
Adult cluster flies, which are a little larger than common house flies range in size from 3/8th to 1/2 an inch long. They are black with short, yellow hairs on their thorax and wings that overlap while resting. The eggs and larvae of cluster flies are very rarely seen as they are deposited into the soil near earthworm burrows. The larvae then feed on the earthworms.
Cluster flies are considered a nuisance pest as they survive the winter by hibernating inside wall voids and attics inside our homes and other buildings. They enter through cracks in the foundation, attic vents, gaps in exterior siding and other small openings in the fall when the temperatures begin to drop. They are primarily dormant over the winter, but may emerge on warm, sunny winter days when some of the flies may become active.
Drain flies, also known as moth flies, range from 1/5th to 1/6th of an inch in length. They are dark or grayish in color and under hand-held magnification drain flies are seen to have a fuzzy, hair-like covered body with large, horizontal wings. Drain flies make poor fliers. They have a short, frenzied flight path and are only able to cover a few feet at best. Drain flies lay their eggs in the moist, organic matter that accumulates inside of drains, in overflow pipes and garbage disposals. The larvae are approximately 3/8th of an inch long, legless and wormlike. Although drain flies do not bite, they may become a nuisance as their populations grow.