Revision of the genus Erythracarus Berlese (Acarina : Anystidae : Erythracarinae)

The mite genus Erythracarus is revised and redefined and the new pyrrholeuc us species group is described. The type species of Erythracarus is establis hed as E. ruricola and the previous designation of Trombidium parietinum as the type is thus declared invalid. Bechsteinia and Chabrieria are newly sy nonymized with Erythracarus. Nine new species are described: Erythracarus a mnicolus n. sp., E. avius n. sp., E. barbarus n. sp., E. ciliatus n. sp., E . decoris n. sp., E. elegans n. sp., E. flavipes n. sp., E. katherinae n. s p. and E. nasutus n. sp. The species E. parietinus, E. pyrrholeucus, E. fes tinus and E. grahami are redescribed and identification keys to known speci es and instars of Erythracarus are presented. E. cluozzai is made a junior synonym of Tarsolarkus articulosus, Bechsteinia solarii and Erythraeus spin atus are made junior synonyms of Erythracarus parietinus, while Bechsteinia californica, B. schneideri and Tarsotomus terminalis are all made junior s ynonyms of E. pyrrholeucus. E. simku is found to be a nomen nudum. E. pyrrh oleucus is recorded for the first time from Australia, Iran and the Ukraine and E. parietinus for the first time from the western United States. The o nly record of E. parietinus from Australia is shown to be based on a miside ntification. Observations on reproductive behaviour are made for five Eryth racarus species. Al of these reproduce sexually by means of stalked spermat ophores, the shape of which is species specific. Spermatophores are often d eposited on top of one another, possibly indicating sperm competition. Male s of one species, E. pyrrholeucus, are unknown and this species is thus lik ely to be thelytokous. Some Erythracarus species are oviparous. E. ciliatus and E. parietinus are ovoviviparous or viviparous. Prelarvae that were stu died were immotile except for those of E. ciliatus, which were able to move their legs. Immotility is a derived character state in Erythracarus and po ssibly an adaptation to more protected habitats.