Morphological ontogeny of Oribatella similesuperbula (Acari: Oribatida: Oribatellidae).

Morphological ontogeny of Oribatella similesuperbula Weigmann, 2001 based on specimens from Romania, is described and illustrated. The nymphs of this species are apopheredermous, i.e. they carry the exuvial scalps of previous instars away from the dorsal integument, using modified setal pair da. The prodorsal and most gastronotal setae of juveniles are long and barbed, except for medium sized h2 and minute h3 in the larva, and medium sized c1, p2 and p3 in the nymphs. The larva has 12 pairs of gastronotal setae, the nymphs have 15 pairs. In all juveniles, a humeral organ is present.

Morphological ontogeny of Perlohmannia nasuta (Acari, Oribatida, Perlohmanniidae), with comments on Perlohmannia Berlese.

The morphological ontogeny of Perlohmannia nasuta Schuster, 1958 is described and illustrated. The adult of this species is the most similar to that of P. dissimilis (Hewitt, 1908), but differs from it by having alveolar seta exp (versus setiform in P. dissimilis), which is unique in Perlohmannia Berlese, 1916. It also has more spines on the bothridial seta and shorter seta c1 than has P. dissimilis. The juveniles of P. nasuta have the prodorsal seta exp alveolar, 78 anterior spines on the bothridial seta, and seta e2 longer than f2. Clapardes organ of larva is long and cudgel-shaped. This species differs clearly from P. dissimilis in the ontogeny of leg setae. In both species, hypertrichy occurs on tarsi, especially on tarsus I, but P. nasuta has more setae on tarsus I of deutonymph, tritonymph and adult than has P. dissimilis.

Morphological ontogeny of Zachvatkinibates latilamellatus (Acari: Oribatida: Punctoribatidae), and comments on Zachvatkinibates Shaldybina.

The morphological ontogeny of Zachvatkinibates latilamellatus Bayartogtokh Aoki, 1998 is described and illustrated. The juveniles of this species are light brown, with several pairs of small, sclerotized depressions on the gastronotum, which are unique in Zachvatkinibates Shaldybina, 1973. The larva has 12 pairs of gastronotal setae, including h3, all are inserted on unsclerotized integument; nymphs have 15 pairs, of which c-series is inserted on individual sclerites, d-, l-, h-series and p1 are on sclerotized integument, and p2 and p3 on unsclerotized integument. In all juveniles, a porose humeral organ is present.

Morphological ontogeny of Liebstadia mongolica (Acari: Oribatida: Scheloribatidae), with comments on Liebstadia Oudemans.

The morphological ontogeny of Liebstadia mongolica Bayartogtokh, 2001 is described and illustrated. The juveniles of this species are elongated and unpigmented. The larva has 12 pairs of gastronotal setae, and three of them are with excentrosclerites (c2, la, lp), the nymphs have 15 pairs, and five of them are with excentrosclerites (c2, la, lp, h2, h3). In all instars, solenidion ω1 on tarsus I is curved laterally, and is shorter than ω2.

Morphological ontogeny of Oribatella hungarica (Acari: Oribatida: Oribatellidae).

The morphological ontogeny of Oribatella hungarica Balogh, 1943 is described and illustrated. The nymphs of this species are apopheredermous, i.e. they carry the exuvial scalps of previous instars away from the dorsal integument, using modified setal pair da. The larva has 12 pairs of gastronotal setae, most of them have long barbs, except for c3 with short barbs and minute h3, whereas the nymphs have 13 pairs with short barbs (dm and dp are lacking). In the tritonymph, leg seta d on all femora and genu IV, l" on femora I and II and pair l on genua and tibiae I and II, l' on femur III and genua and tibiae III and IV, and ft on tarsi II-IV are thicker than other setae on these segments. In all juveniles, a humeral organ is present. In the adult, epimeral seta 4c and leg seta l" on genua and tibiae I and II, and l' on genu III and genu and tibia IV are thickened.

Morphological ontogeny of Ctenobelba brevipilosa (Acari: Oribatida: Ctenobelbidae).

The morphological ontogeny of Ctenobelba brevipilosa Mahunka, 1964 is described and illustrated for the first time; this species was investigated since its description mainly in ecological aspect. The adult instar is of medium size, with setiform bothridial seta, bearing 11-17 anterior branches, and with short notogastral setae. Seta d is absent from genua I-III and all tibia. The bothridial seta of juveniles is setiform and barbed, and prodorsal and gastronotal setae are short, except of medium sized ro. Nymphs are quadrideficient and eupheredermous, i.e. they carry the exuvial scalps of previous instars. Anal valves of protonymph and deutonymph have two pairs of alveolar setae, which is rare in Brachypylina. In the juvenile instars, seta d on all genua and tibiae is present.

Morphological ontogeny of Punctoribates astrachanicus (Acari: Oribatida: Punctoribatidae), and comments on Punctoribates Berlese.

The morphological ontogeny of Punctoribates astrachanicus Shaldybina, 1973 is described and illustrated. This species was rarely investigated since its description, including its ecological and biological aspects. The adult has fusiform bothridial seta, straight anterior tectum of notogaster, four pairs of saccules, and notogastral setae mostly alveolar, except for short p-series. Tarsus I has a short dorsal projection. Juveniles of this species are light brown, with short and thin prodorsal seta ex, and relatively large humeral organ. The gastronotal setae of larva are of medium size and pointed, in nymphs they are short.

Morphological ontogeny, ecology and some biological parameters of Achipteria nitens (Acari: Oribatida: Achipteriidae).

The morphological ontogeny of Achipteria nitens (Nicolet, 1855) from Crimea peninsula is redescribed and illustrated, and ecology and some biological parameters of this species are investigated. The larva of this species has short, thick and barbed setae in and of c-series, and anterior part of prodorsum reticulate, whereas the nymphs have most gastronotal setae of medium size and barbed, except for shorter c3, and shorter, thick and smooth p2 and p3. A key to the larva and nymphs of eight species of Achipteria Berlese, 1885 is provided.

Oviposition behaviour of the soil mite Veigaia cerva (Acari: Veigaiidae).

We observed the oviposition behaviour of the soil mite Veigaia cerva (Kramer) (Acari: Veigaiidae) using continuous video-monitoring. Five phases could be recognized. Phase I involved inspection of the substrate. In phase II the female rhythmically moved her gnathosoma and first pair of legs. After an inactive phase III, the soma was raised (IV), and the egg was laid (V). In the actual egg laying three sub-phases could be distinguished: internal egg movement, placing the egg in front of the gnathosoma, and depositing the egg using the chelicerae. The palps and first pair of legs were used to position the egg between the chelicerae. The whole process took on average 333 ± 22 s.

Oviposition behaviour of the soil mite Pergamasus brevicornis (Acari: Parasitidae).

We observed the oviposition behaviour of the soil mite Pergamasus brevicornis Berlese (Acari: Parasitidae) using continuous video-monitoring. Oviposition consisted of six sequential phases. The first phase (I) involved inspection of the substrate. In the second phase (II) there were rhythmic movements of the first pair of legs and slight reciprocating movements of the body. The third (III) was a resting phase. In the fourth phase (IV) the gnathosoma was lowered and the body was raised. In the next phase (V) there were two sub-phases. During the first (Va), the female held the egg below the gnathosoma. In the second sub-phase (Vb), the gnathosoma moved up holding the egg, which was then placed on the substrate. The last phase (VI) involved intense 'cleaning' movements of the chelicerae and palps. During Va a protective external eggshell structure is gradually formed, involving a phase where the egg shell is sticky. After moving the egg to the substrate, the female freed her palps and chelicerae from the sticky egg shell and cleaned her gnathosomal appendages. Phases II-V took on average 207 ± 69 s.