Differentiation of external morphology of Oribatella Banks, 1895 (Acari: Oribatida: Oribatellidae), in light of the ontogeny of three species

Abstract

Differentiation of external morphology of Oribatella Banks, 1895 was investigated, in light of the ontogeny of O. quadricornuta (Michael, 1880), O. superbula (Berlese,1904) and O. calcarata (CL Koch, 1835) studied here for the first time, and that of the other species from the literature. The pattern of gastronotal setae in larvae is similar, except for lack of seta h 3 in O. nortoni Behan-Pelletier, 2011, while that of nymphs and adults is differentiated. The nymphs of most species have 15 pairs of gastronotal setae, but those of O. metzi Behan-Pelletier, 2011 and most nymphs of O. calcarata have 13 pairs. The nymphs of most species carry the exuvial scalps of previous instars on apical parts of gastronotal setae da, while setae dm and dp, located under these scalps, are subjected to translocation, reduction in size or loss. In O. berlesei (Michael, 1898), O. nortoni, O. quadricornuta and O. sexdentata Berlese, 1916 pair dp takes a more lateral position, compared with the larvae, in O. superbula and O. canadensis Behan-Pelletier and Eamer, 2010 it is reduced in size (in the latter species pair dm is also reduced), while O. metzi loses setae dm and dp. In contrast, the nymphs of O. calcarata do not carry the scalps, and usually lose setae c 1 and dm. The adults of all species lose setae c 1 , c 3 and d-series, compared with the tritonymph, and only 10 pairs of notogastral setae remain (c 2 , l-, h-and p-series), but O. quadricornuta and O. calcarata rarely retain seta c 3 unilaterally, which indicates the order of setal loss in Oribatella according to Shaldybina (1972). IntroductionThe adults of Oribatella Banks, 1895 are easy to recognize by their long, wide lamellae, which cover the main part of the prodorsum, and are connected together in medial and posterior parts. The area between lamellar cusps is deeply incised, with strong lamellar seta in the middle, and the length of cusps is species specific. Interlamellar setae are long and usually strong, and often protrude beyond the rostrum, while the shape of the sensillus depends on species and can be clavate, fusiform or setiform. The notogaster is almost hemispherical, with four pairs of porose areas and usually 10 pairs of notogastral setae, which are inserted on the lateral and posterior parts of the notogaster, and most are curved outwards and ventrally, as in O. quadricornuta (Michael, 1880), O. superbula (Berlese,1904) and O. calcarata (CL Koch, 1835) investigated here.

Morphology, distribution and certain population parameters of the Arctic miteOribatella arctica(Acari: Oribatida: Oribatellidae)

“…The ontogeny of this species is similar to that of O. quadricornuta, which was investigated by Seniczak and Seniczak (2013), so the comparison of the morphology and illustrations are limited to the body regions that show substantial differences, including the dorsal aspect of the larva and tritonymph, anal region of the larva and anogenital region of the tritonymph. The presence and shape of setal pair dp vary in nymphs and therefore illustrations of the gastronotum of protonymph and deutonymph in dorsal aspect are presented.…”

“…There are four pairs of porose areas, or saccules, on the notogaster. The species differ from one another mainly by the shape of the lamella and lamellar cusps, presence of translamella, shape of the sensillus, shape of the rostrum, length of most notogastral setae, location of setae lp, h 2 and h 3 , body size, number of claws on legs, and shape of epimeral seta 4c (Bernini 1974a(Bernini , 1974b(Bernini , 1977(Bernini , 1978Bernini and Avanzati 1983;Behan-Pelletier and Paoletti 1993;Weigmann 2006;Shtanchaeva and Subías 2009;Behan-Pelletier and Eamer 2010;Bayartogtokh 2010;Behan-Pelletier 2011;Behan-Pelletier and Walter 2012;Seniczak and Seniczak 2013;Walter et al 2013). Oribatella comprises 94 species and two subspecies (Subías 2014).…”

“…(5) Oribatella sexdentata Berlese, 1916: Chistyakov (1984b described and illustrated the morphological ontogeny. (6) Oribatella superbula (Berlese, 1904): Seniczak and Seniczak (2013) described and illustrated the morphological ontogeny. The morphological ontogeny of some species of Oribatella is incomplete.…”

“…(3) Oribatella canadensis Behan-Pelletier & Eamer, 2010: Behan-Pelletier and Eamer (2010) described and illustrated the morphological ontogeny. (4) Oribatella quadricornuta (Michael, 1880): Michael (1880aMichael ( , 1880bMichael ( , 1884 described and illustrated the morphology of a nymph and Seniczak and Seniczak (2013) described and illustrated the morphological ontogeny. (5) Oribatella sexdentata Berlese, 1916: Chistyakov (1984b described and illustrated the morphological ontogeny.…”

“…(2) Oribatella calcarata (C. L. Koch, 1835): Grandjean (1953a) and Norton and Behan-Pelletier (2009) investigated some parts of the body of juveniles of this species in a wide phylogeny context and Seniczak and Seniczak (2013) described and illustrated the morphological ontogeny. (3) Oribatella canadensis Behan-Pelletier & Eamer, 2010: Behan-Pelletier and Eamer (2010) described and illustrated the morphological ontogeny.…”