Education Center

Yes, the species included in Fly Predators do all reproduce. However, like in other predator/prey cycles, nature balances itself to always have an abundance of prey to sustain the predators that are there. Because of this, when not actively forced to stay above natural levels, populations quickly balance themselves out again. Our program is considered Augmentative Biological Control, because we are adding to naturally existing populations. Whether the Fly Predators are raised in the insectary or in the wild, they are all capable of reproduction; however, when fly populations start to drop, the parasitoids will begin actively leaving some fly pupae to ensure the next generation of their own offspring won’t starve. It’s one of the ways nature keeps everything in balance. Nature happy fly control doesn’t quite match up with human happy fly control though, so we use the augmentative releases to force the predator population to remain high, even as fly numbers begin to drop.

Fly Predators are tiny parasitic insects that kill nuisance flies before they become adults.

Fly Predators in nature live between 2 and 5 weeks depending on season, temperature, food availability, and humidity. The average life span is generally 3-4 weeks.

Do I need to leave manure behind for Fly Predators when cleaning?

Fly Predators are effective primarily against house flies (Musca domestica) and stable flies (Stomoxys calcitrans).

Fly Predators look similar to a small ant or gnat.

When fly populations start to drop, Fly Predators will begin actively leaving some fly pupae to ensure the next generation of their own offspring won’t starve. It’s one of the ways nature keeps everything in balance. Nature happy fly control doesn’t quite match up with human happy fly control though, so we use the augmentative releases to force the predator population to remain high, even as fly numbers begin to drop. Also, female Fly Predators only produce about 100 eggs in their lifetime compared to over 1,000 produced by female flies. Because of this, regular releases of Fly Predators are necessary to keep up with the faster production of pest flies.

Fly Predators are made up of a mix of 3 species of parasitic insects in the family Pteromalidae. These include Muscidifurax zaraptor, Muscidifurax raptorellus, and Spalangia endius (occasionally exchanged for Spalangia cameroni). By sending you a mix of these species, we ensure the widest range of coverage for fly control on your farm. How so? Muscidifurax species like to search along the surface of fly breeding habitats, do better in cooler temperatures, and are very efficient against house flies. Spalangia species have been found to seek out fly pupae at deeper depths, do better in warmer temperatures, and are more efficient against biting stable flies.

After a female Fly Predator emerges from the host pupa as an adult, she will quickly mate and begin searching for developing flies. When she locates an unparasitized fly pupa, she will eat some of them and lay eggs in others. The eggs hatch inside the host pupa and feed on the fly (killing it in the process) as they grow. How fast the Fly Predators develop depends heavily on temperature. At temperatures above 90°F, development from egg to adult will take a minimum of 14 days. At 70°F this extends to a minimum of 30 days to develop from egg to adult. As winter approaches and temperatures drop, some developing Fly Predators will enter a state called diapause that is similar to hibernation. While in diapause, development halts until temperatures begin to rise again, at which time the developing Fly Predators will complete their development.

No, Fly Predators are very host specific, meaning there are only a small number of fly species they can kill, and they are unable to kill any aquatic or semi-aquatic fly species such as mosquitoes, midges, horse flies, and deer flies.

Generally, stalls are cleaned often enough to prevent fly development in the stalls. We often see adult flies in stalls, as they like to come in out of the elements and are drawn to the opportunities to feed themselves. Fly breeding more often takes place outdoors in areas where we cannot clean as well and where decaying organic material will be around long enough to support development. However, if stalls are lined with heavy mats that cannot easily be cleaned under, you may want to add a small pinch of Fly Predators to a corner of the stall when distributing.