Arctoseiinae Evans 1963

Subfamily Arctoseiinae Evans, 1963

We propose a subdivision of the subfamily Arctoseiinae Evans, 1963 into three tribes, Arctoseiini Evans, 1963 (numbering about 60 species), Zerconopsini tribe n. (about 25 species), and monobasic Maxiniini tribe n.

The strongly evident relationship of Iphidonopsis, Zerconopsis, and Xenoseius is based on apomorphic attributes (dorsoproximal setae ad -2 and pd -2 of tarsi II to IV elongated, curved, somewhat whip-like; hypostomal setae hp -1 and to some extent hp -3, as well as the internal palp trochanter seta elongated, whip-like) and on a plesiomorphic attribute (genu III with eight setae, including pv -1). Besides, females of these genera possess an often expansive ventrianal shield usually bearing one to six pairs of opisthogastric setae in addition to the circumanal setae (female Iphidonopsis exceptional, having a large anal shield bearing only the circumanal setae) along with one or two pairs of free metapodal platelets. All these characteristics argue for the deriving of a tribe Zerconopsini tribe n. Segregation of the tribe Arctoseiini Evans, 1963 (including Arctoseius and Iphidozercon) is supported by such apomorphic attributes as reduced ventral sclerotisation (epigynal shield slender, anal shield bearing only three circumanal setae, sternal shield sometimes separated from endocoxal sclerites) and genu III with seven setae, lacking pv -1. Recognition of the monobasic Maxiniini tribe n. is strongly based apomorphically on a narrowed deutosternum, a highly expanded ventrianal shield incorporating metapodal platelets and bearing setae JV 1, along with the absence of setae ZV 1 in both sexes.

Although the single known species of Maxiniini seems to be free-living in soil litter throughout all its broad range (Lindquist & Makarova, 2012), numerous members of the two other tribes display some clear tendencies in their ecological specialisation associated phoretically with winged dipterans, namely an inclination to fungal substrata in Zerconopsini and to different wet habitats enriched by nematoceran juveniles (eggs, early stage larvae) in Arctoseiini.