Life Cycle of Flesh Flies

Flesh fly mating occurs most commonly in spring. Flesh fly eggs remain inside a female’s abdomen until they hatch, at which point females deposit larvae into manure or decomposing flesh. Each flesh fly species prefers different bodies, with varying decomposition stages. Regardless, each egg-laying site is carefully selected to ensure an abundance of food for the larvae.

A single female can produce hundreds of eggs during her lifetime, and more than 25 larvae may hatch at one time. Depending upon the species, eggs may hatch within 24 hours and the entire life cycle of the flesh fly may be complete within one to three weeks.

Larvae are yellow in color, with pointed heads. They thrive in decaying meat, manure and garbage. Some flesh flies prefer to breed inside dead rodents and birds found in attics, crevices and wall voids. However, the larval stage of the flesh fly may prove beneficial to humans, as larvae feed on other pests. Flesh fly larvae feed for approximately four days.

After feeding, larvae of flesh flies pupate. While some pupae remain dormant for several weeks, most species emerge as adults within 12 to 15 days. These adults measure 10 to 14 mm in length and are gray in color, with dark black or brown stripes along the thorax.