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Dump Fly

Common names: Black Dump Fly, Dump Fly

Scientific name: Order Diptera, family Muscidae, Hydrotaea aenescens


Size: Same size as the common house fly, 1/8" to 1/4".

Identification: The adult fly is a shiny black fly similar to the housefly. These beneficial flies do not bother animals or people. They have little movement or flight, unlike house flies.

Biology and life cycle: Females lay an average of 170 eggs over a seven- to ten-day period. Eggs hatch in eighteen to twenty-four hours. There are three larval stages and a pupal stage, which changes into an adult fly. Adults mate after about five days; two days later, the females start laying eggs. The egg-to-adult period is about fourteen days or shorter.

Habitat: Like dark locations and stay close to the ground. Love manure pits.

Feeding habits: The larvae (or maggots) are predators of the larvae of house flies and other flies.

Economic importance: Control of house flies resulting from animal manures.

Natural control: None needed.

Organic control: None needed.

Insight: According to Dr. J. A. Hogsette of the USDA-Agricultural Research Service and the University of Florida, its former name was Ophyra aenescens. It is native to the United States as well as Central and South America. Black fly larvae don't need to feed on other fly larvae to live. They can develop naturally on the nutrients from the manure.

Notes:  Dump flies can kill up to twenty house fly larvae a day--a rare example of an animal killing more than it can eat. Dump flies do not feed or rest on animals or humans. Black dump flies have been used successfully in poultry and swine houses, according to Dr. Hogsette. The larvae seem to prefer manures that are comparatively low in fibrous materials. They do not develop well in manures of cattle, horses, sheep, or goats. That apparently means they prefer poultry, dog, and cat manure.

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