The major predators of flies in confined-animal operations are as follows:
Beetle predators in the families Staphylinidae and Histeridae may be abundant in manure. The most common and abundant are usually histerids in the genus Carcinops, especially C. pumilio (Erichson).
These are small black beetles whose adults and larvae feed on the eggs and larvae of flies.
The adults of Carcinops pumilio may consume 13–24 house fly eggs per day, while larvae are able to consume 2–3 eggs per day. The life cycle of this beetle, from egg to adult, requires about 40 days at 25°C (77°F).
Mite predators of fly eggs and first-instar larvae are mainly species of the families Macrochelidae, Uropodidae and Parasitidae.
Typically, as manure accumulates and ages, the order of invasion by these mites is: Parasitidae – Macrochelidae – Uropodidae.
The parasitids are poorly understood, but have been observed feeding actively on fly eggs.
The life stages of the parasitids are egg, larva (6-legged), protonymph, deutonymph, and adult, with the last three stages having eight legs.
The deutonymphs are usually most obvious and abundant. They move about very rapidly in manure and can be recognized by their light yellow-brown bodies, with the dorsal aspect appearing to be divided into two parts, with darker brown dorsal shields.
The deutonymphs attach to beetles or flies which transport them to new areas.
Species of parasitic mites in the genus Poecilochirus are frequently found in livestock and poultry manure.
