In accumulations of piled manure there is a distribution of macrochelid and uropodid mites, and Carcinops beetles, making them complimentary predators of flies.
Macrochelids are found mostly in the outermost layer of manure, in areas likely to be used by the flies for oviposition. Uropodids are found deeper in the manure.
Macrochelids prefer the egg stage, move rapidly and have well-developed olfactory senses.
Those fly eggs which escape predation by the macrochelid hatch into first-instar larvae. Being negatively phototropic, these larvae move deeper into the manure where the uropodid mites aggregate.
Group attacks and the gregarious feeding behavior of uropodids tend to contain fly larvae while they are being destroyed.
Carcinops beetles tend to be on and slightly beneath the manure surface, where they can easily find fly eggs in a similar manner to the macrochelids.
Beetles found deeper in the manure feed on the first-instar larvae. Beetles, like uropodids, tend to aggregate and engage in group feeding.
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