Morphology of Juvenile Stages ofMetabelba glabrisetaMahunka, 1982 andDamaeus auritusKoch, 1835 (Acari: Oribatida: Damaeidae)

Abstract

The morphology of juvenile stages of the oribatid mites Metabelba glabriseta Mahunka, 1982 and Damaeus auritus Koch, 1835 (Damaeidae) is described and illustrated. The juveniles of Metabelba glabriseta are characterized by: cuticle smooth, with rare folds and also with slightly developed reticulate ornamentation dorso-laterally; cerotegument of body with conical or strongly oblong granules, that of some body setae cloud-like; rostral and lamellar setae of approximately identical length, with hardly developed barbs; sensilli with long flagellate tips, smooth; gastronotic region rounded posteriorly; almost all gastronotic setae with small flagellate tips, barbed, setae lp longest in larva, setae c1, c2, h1 longest in nymphs; cornicle k of nymphs long, slightly curled, distally slightly swollen and longitudinally split; all legs of juveniles shorter than body; setae d and v” on trochanter III appear in adult; famulus emergent. The juveniles of Damaeus auritus are characterized by: cuticle smooth, with rare folds; cerotegument of body with spherical granules, body setae without cerotegument; prodorsal setae barbed, setae ex and larval setae in short, strong, sensilli thickened, but with thin, bent tips; gastronotic region truncate (in larva) or rounded (in nymphs) posteriorly; some gastronotic setae vane-like; cornicle k of nymphs short, strong, conical; all legs (except II in nymphs) of juveniles longer than body. Famulus sunken. Juveniles are compared among the known species of Metabelba and Damaeus, and also among the genera Metabelba, Damaeus and Epidamaeus.