Blow Fly

Common Name: Fly – Blow flies
Latin Name: Phaenicia sericata
Common Family Name: Blow flies
Latin Family Name: Calliphoridae

Other Names: Bottle flies

Origin: Several species that are native to North America, and widely spread throughout the continent and into Latin America.

Biology: The blow flies are important decomposers of dead animals and other rotting organic material, such as decomposing plant material. They are the first insects to arrive at a newly deceased carcass and their larvae are frequently used in forensic science to determine facts about a crime scene. The maggots also have been used in “maggot therapy”, to eat dead tissue off the skin of victims of burns or wounds. Females may lay several hundred eggs on an appropriate larval food source, with development to the adult stage being completed in about one week in hot, humid conditions. The larvae leave the food and may squirm long distances to find a protected crevice in which to pupate, often falling through ceilings or across floors because of this.

Identification: In general the blow flies are shiny and metallic, with species ranging from green to bright blue to a coppery orange to almost black, and species names are assigned accordingly. The adults are from 10 to 15 mm long and robust, with compact, wide bodies. They are loud, buzzing fliers and are strongly attracted to lights. The larvae are the typical legless, white maggots of the filth flies, with the head end noticeably tapering to a point and the posterior much wider and flattened from behind. Identification to species is done based on the specific patterns of the lines of the spiracles, found at the posterior end.

Characteristics Important in Control: Control of the source of the larvae is critical, involving cleanup and proper maintenance of garbage containers, removal of dead rodents or birds, and elimination of piles of yard debris or animal feces outdoors. Adult entry to structures is prevented by good building maintenance. The use of UV light traps is highly effective in trapping adults, along with bait granules or bait strips, and possible use of residual insecticides on surfaces the adults frequent.