Systematic position of Fuscozetes setiger (Acari: Oribatida: Ceratozetidae) in the light of ontogenetic studies

Abstract

The systematic position of Fuscozetes setiger (Trägårdh, 1910) n. comb. is investigated in the light of ontogenetic studies. This species is classified by most authors as Trichoribates Berlese, 1910, but this classification is not supported by the morphology of juvenile stages of this species. In all juveniles of F. setiger, a humeral organ is present, and all nymphs have a humeral sclerite, which is typical of Fuscozetes Sellnick, 1928. The larva has a pygidial sclerite, with three pairs of setae (dp, lp, h1), the nymphs have a gastronotal sclerite, with 10 pairs of setae (d-, l-, h-series and p1), and setae p2 and p3 are inserted on unsclerotized integument. The nymphs have a large humeral sclerite, bearing seta c1, while setae c2 and c3 are inserted on unsclerotized integument. The adult of F. setiger has thin seta l" on genu and tibia I and II, which is typical of Fuscozetes.