May 15, 2012. Found this in a bush in my yard this evening. The gold and copper glistened in the setting sun with shimmering undertones of sparkling green.
Blow flies and bottle flies are medium sized, robust flies approximately 1/5 inch in length easily identified by their metallic appearance. Coloration varies mostly from blue, green and gold to shiny black.
Biology and Behavior:
Blow/bottle flies will lay their eggs on animal carcasses and manure as well as decaying vegetables, grass clippings and leaves.
Eggs are laid on a suitable decaying organic material and larvae hatch out and burrow beneath the surface where they feed.
After a few days feeding, larvae emerge and crawl a short distance away from the breeding source and burrow into the soil to pupate. Adults emerge several days later.
The entire blow/bottle fly life cycle can take from 10 days to three weeks depending on environmental conditions.
Forensic entomologists track these environmental conditions and compare to larval development from maggot specimens collected from bodies to help determine time of death. A single mouse carcass can produce over 100 adult flies.
The presence of blow/bottle fly adults and larvae inside of structures is usually related to the presence of a carcass, such as a rodent or bird that died inside a wall void, attic or crawlspace.
Pet feces, piles of moist grass clippings and leaves and poorly maintained garbage cans are all good sources of blow/bottle flies in a residential setting.
Removing the breeding source is the best long term control. However, some carcasses are difficult or unfeasible to locate. In such cases, relief may be attained by vacuum removal and crack and crevice dust applications to reduce numbers of emerging larvae.
Baits, insect light traps and residual applications to resting sites help eliminate adult populations.