- Color: black blowfly – dark metallic green; green bottle flies – metallic blue-green; and bluebottle flies – metallic blue. Larvae (maggots) – cream-colored
- Size: 1/4 inch for the black blowfly to more than 1/2 inch for the bluebottle flies; mature larvae (maggots) are 3/8 to 7/8 inch long.
- Sponging mouthparts.
- Larvae (maggots) are legless, eyeless, and taper from the larger round rear segment to the pointed head which consists of a pair of mouth hooks.
- Larvae have large spiracles on the posterior plate.
Green, Blue Blow, and Bottle Fly Habits:
- Females lay from 540 to 2,373 eggs in their lifetime.
- Eggs are laid in batches of 100 to 180 on meat, fish or carrion; blowflies are also attracted to animal manure, garbage, and rotting vegetable matter.
- The larva and the pupa are the overwintering stages.
- Development time (egg to adult): as short as 10 days but typically 15 to 20 days.
- Blowflies can be found developing inside the decaying bodies of rodents and other dead animals within attics, wall voids, and chimneys.
- Some species are strong fliers.
- They are attracted to bright light.
Damage Caused by Green, Blue Blow, and Bottle Flies:
- Blowflies seldom are a significant problem within structures but can be quite annoying because of their persistent buzzing.
- The major health concern associated with blowflies is their ability to carry disease-causing organisms on their bodies.
- Fly specks (small black fecal deposits).
- Larvae leaving the breeding medium in order to pupate.
- Decaying organic matter or dead animal.
- Areas where adults rest and congregate at night.
How to Control and Kill Green, Blue Blow, and Bottle Flies:
- Sanitation, or source-reduction, is the most important step in blowfly control because larval breeding sites are eliminated.
- Trash cans should be cleaned at least weekly in order in order to disrupt the developmental cycle.
- In areas such as stables, barns, pet kennels, and poultry houses, animal feces must be spread out in order to dry and be disposed of weekly.
- Insect-proof garbage containers, self-closing doors, screening, and caulking to exclude flies should be used.
- Electric fly traps, sticky traps and other devices should be used to reduce adult fly populations indoors and out.