Systematic status of Oribatula Berlese, 1895 (Acari: Oribatida: Oribatulidae) in the light of the ontogeny of three species

Abstract

The systematic status of Oribatula Berlese, 1895 in light of the ontogeny of Oribatula interrupta (Willmann, 1939), Oribatula propinqua (Oudemans, 1900), Oribatula exarata (Berlese, 1916), and the literature was investigated. Oribatula and Zygoribatula Berlese, 1917 are distinguished as separate genera or subgenera mainly by the absence or presence of translamella in adults, respectively, but the shape of the translamella varies in O. interrupta, Oribatula colemani (Franklin, Norton & Crossley, 2008), and other species, which presents problems with their classification and puts into question the importance of translamella as a generic or subgeneric character. The morphology of juveniles of the species investigated here also does not support the importance of translamella; these juveniles have similar body shape and excentrosclerites at gastronotal setae c 2, la, lp, and h 1 in the larva and c 2, la, lp, h-series, and p 1 in the nymphs, but differ mainly by the pattern of cuticle of gastronotum, length of certain setae, and number of setae of p-series in nymphs, which are species specific. Their adults differ mainly by the shape of translamella, number of setae of p-series, and pattern of integument on the notogaster, which are also species specific. In the light of these investigations, Zygoribatula should be considered a junior synonym of Oribatula.