Macrochelidae is a family of mites in the order Mesostigmata.

Description

Adult females of Macrochelidae have: an undivided dorsal shield bearing at least 28 pairs of setae, a sternal shield with three pairs of setae, a genital shield with one pair of setae and with a pair of conspicuous accessory sclerites beneath lateral margins, usually a ventrianal shield with 1–5 pairs of setae in addition to circumanal setae, peritreme usually looped around stigma, and movable cheliceral digit usually with a well-developed arthrodial brush at the base. Adult males are similar but with a holoventral shield or separate sternigenital and ventrianal shields.

Reproduction

Macrochelidae reproduce sexually and some can also reproduce asexually. Species of Geholaspis and Macrocheles can perform thelytoky, the production of female offspring from unfertilised eggs. Species of Glyptholaspis, Holostaspella and Macrocheles can perform arrhenotoky, the production of male offspring from unfertilised eggs.

Ecology

Mites of this family are predators. The majority of species are coprophilous, meaning they live in animal dung and feed on the prey available there (oligochaete worms, nematodes, arthropod eggs and larvae). Dung offers high prey availability and shelter from the weather, but it is a temporary resource. Melicharids therefore attach to insects (e.g. scarab beetles or flies) to be carried to fresh dung deposits; this is known as phoresis. Adult females tend to be the ones that engage in phoresis, though males and nymphs can do it as well.

Some macrochelids are believed to be facultatively parasitic on their hosts, rather than phoretic. An example is Macrocheles muscaedomesticae on flies.

Other macrochelids occupy habitats such as forest litter, decaying plant debris, beach wrack or the nests of various animals.

Biological control

Because of their predatory nature, some macrochelids have potential as biological control agents of pest insects, such as flies and thrips. The species Macrocheles robustulus is commercially available for this purpose.

Taxonomy

Macrochelidae contains the following genera and species: