Gastronotal Setae Research Articles

Differentiation of external morphology of Oribatulidae (Acari: Oribatida) in light of the ontogeny of three species

In this paper the differentiation of external morphology and ontogeny of Oribatulidae were investigated, on the basis ofPhauloppia lucorum (C. L. Koch, 1841), Lucoppia burrowsi (Michael, 1890), and Oribatula tibialis (Nicolet, 1855),which ontogeny is described and illustrated here for the first time. The juveniles of these species have smooth cuticle, aclavate sensillus with barbed head, and similar formulae of coxisternal, genital and aggenital setae, but differ mainly inbody size, formulae of gastronotal setae, number of setal excentrosclerites on the gastronotum, and shape of some setae.The number of setal excentrosclerites and presence of seta h 3 in larva differ the juveniles of Ph. lucorum and L. burrowsifrom those of O. tibialis, and seem to have generic value, and are also associated with the number of notogastral setae inadults (14 pairs in two former species, 13 pairs in latter species). The juveniles of O. tibialis lack excentrosclerite at setalm, comparing to those of Ph. lucorum and L. burrowsi, and this morphological character is shared with ScheloribatesBerlese, 1908 and Liebstadia Oudemans, 1906 from the family Scheloribatidae. The larva of O. tibialis lacks seta h 3 , sim-ilarly as that of Scheloribates, while the larvae of Ph. lucorum, L. burrowsi, and Liebstadia have this seta. Presence ofsetal pair c 3 in adult of Zygoribatula cf. frisiae (Oudemans, 1900) is recorded here for the first time, which indicates the order of loss of setae of c-series in Oribatulidae according to Grandjean (1951, 1958, 1968).

The ontogeny of morphological traits in three European species of Cosmochthonius Berlese, 1910 (Acari: Oribatida: Cosmochthoniidae)

The morphology of juvenile stages and ontogeny of Cosmochthonius reticulatus Grandjean, 1947, C. foliatus Subías, 1982, and C. ugamaensis Gordeeva, 1980 are described and illustrated for the first time, and compared to the adults. Juveniles of these species differ mainly by the number of cilia on hypertrophied setae of e- and f-series, the shape of seta h 1 in the larva, and the shape of posterior gastronotal setae in nymphs. Cosmochthonius reticulatus has the fewest cilia on these setae, while the larva of C. ugamaensis and the nymphs and adult of C. foliatus have the most. In all species the number of cilia increases during ontogeny, more so in C. foliatus than in C. ugamaensis and C. reticulatus. Adults of these species differ mainly by the pattern of cerotegument and cuticle, best seen in SEM micrographs. Apparent in light microscopy the pygidium of C. reticulatus is reticulate, that of C. foliatus has rounded foveae, while that of C. ugamaensis has small circles and semicircles. The cuticle of the latter species is covered with thin, granular cerotegument, while that of the other species has thick, netlike cerotegument; C. foliatus also has a cerotegumental collar. Adults of all species differ also by the shape of posterior notogastral setae, and the location of some genital setae.

Differentiation of external morphology of Damaeidae (Acari: Oribatida) in light of the ontogeny of three species

Morphology of juvenile stages and ontogeny of Damaeus onustus C. L. Koch, 1844, Damaeus clavipes (Hermann, 1804) and Kunstidamaeus tecticola (Michael, 1888) was investigated. The juveniles of these species differ mainly in body shape and size, and shape of some setae on the gastronotum and legs. The nymphs of all species lose centrodorsal setae of the d-series, and carry the exuviae of previous instars, but D. onustus carries also compact humus mass adhering to exuviae, D. clavipes a lot of loose debris, while K. tecticola usually only exuviae. The kind of camouflage is partly determined by the shape of gastronotal setae; in D. onustus these setae are curved ventrally, in D. clavipes are raised, while in K. tecticola are raised, and strongly curved medial. The nymphs of these species, as the nymphs of all other known Damaeidae, have gastronotal cornicle, which connects the exuviae of previous instars to the gastronotum. The cornicle of particular species differs in shape and location on the gastronotum; in some species is located anteromedial to setae la, in the other between setae lm, and in the other yet between setae lp or h 3 . The adults of these species differ mainly in body size, presence and shape of cuticular apophyses on the body, length of some setae on the prodorsum and notogaster, and the number of setae on legs, including dorsal seta d on genua I–III and tibiae I–IV.

Ontogenetic studies of three species of Gymnodamaeidae (Acari: Oribatida) with a focus on regressions of hysterosomal setae

Ontogeny of loss of gastronotal setae in Arthrodamaeus reticulatus (Berlese, 1910), Gymnodamaeus bicostatus (C.L. Koch, 1836) and Jacotella neonominata Subías, 2004 was investigated. From the larval setation, the protonymph of these species loses three pairs of d-series and two pairs of l-series; these losses continue through subsequent nymphal stages and adult. Between tritonymph and adult, setae of h-series are subject to loss; A. reticulatus loses none, G. bicostatus loses one pair (h 3) and J. neonominata loses two pairs (h 2 and h 3). The nymphs of these species bear the gastronotic exuviae of previous instars, but they differ in the appearance of the exuviae, the manner of their connection with the gastronotum, and the shape of setae c 3 and lp, which in some species helps secure the exuviae to the body. Other aspects of ontogeny of these species are described and illustrated for the first time, and morphological characters that distinguish Arthrodamaeus, Gymnodamaeus and Jacotella are discussed.

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

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.

Morphology of Juvenile Stages ofPedrocortesella africanaPletzen, 1963 andAleurodamaeus africanusMahunka, 1984 (Acari: Oribatida)

Abstract. The morphology of juvenile stages of the oribatid mites Pedrocortesella africana Pletzen, 1963 and Aleurodamaeus africanus Mahunka, 1984 is described and illustrated. The juveniles of Pedrocortesella africana are characterized by: cuticle with reticular ornamentation and folds; body with microgranular cerotegument; prodorsal setae leaf-shaped, sensilli petiolate, tuberculate blades with a rounded distal margin; gastronotic region flat; larva and nymphs with nine pairs of leaf-shaped gastronotic setae; scalps folded, larval scalp with seven pairs of setae, nymphal scalps with six pairs of setae; leg famulus sunken. The juveniles of Aleurodamaeus africanus are characterized by: cuticle smooth; body with filamentous cerotegument and with very not numerous granules; prodorsal setae setiform (except short interlamellar setae in nymphs); gastronotic region convex in lateral aspect; larva and nymphs with 12 of setiform gastronotic setae; scalps with reticular ornamentation, larval scalp with nine pairs...

Differentiation of body form of Gustavioidea (Acari: Oribatida) in the light of ontogeny of three species

Differentiation of body form of Gustavioidea in the light of ontogeny of Dorycranosus curtipilis (Liacaridae), Ceratoppia sphaerica and Ceratoppia quadridentata (Peloppiidae) was investigated, and morphology of juveniles of these species was described and illustrated for the first time. The juveniles of D. curtipilis differ distinctly from those of Ceratoppia species mainly by stronger chelicerae, more elongated body, and convex gastronotum, oval cross section, small and clavate sensillus, and rather thin, and pliable setae. The protonymphs of all these species lose gastronotal setae of d-series, and these setae are absent in subsequent nymphs and adult. The adult loses further notogastral setae, such that 11 pairs remain in D. curtipilis, but only two pairs in Ceratoppia species. Diagnoses of these species are enriched with morphological characters of juveniles, and the morphology of Ceratoppia bipilis is briefly compared, as are aspects of Gustavia fusifer (Gustaviidae).

Morphology of Juvenile Stages of <I>Epidamaeus kamaensis</I> (Sellnick, 1925) and <I>Porobelba spinosa</I> (Sellnick, 1920) (Acari: Oribatida: Damaeidae)

Detailed morphological descriptions of juvenile stages of two oribatid species from the family Damaeidae: Epidamaeus kamaensis (Sellnick, 1925) and Porobelba spinosa (Sellnick, 1920) are presented. Juvenile stages of E. kamaensis and earlier known immatures of Epidamaeus (E. puritanicus, E. longisetus) differ by minor differences in setal structure and measurements. Juvenile stages of Epidamaeus and Damaeus differ by the following characters: shape of exuvial attachment cornicle in nymphs, correlation of the length and structure of gastronotal setae, the larval body posterior, form of sensilli, and leg setation. Juvenile stages of these two genera are identical in genital, aggenital, anal, adanal, gastronotal and epimeral setation, structure of famulus, and structure of cerotegument. Moreover, in the present paper new data about immatures of Porobelba spinosa. It is the first record of all juvenile stages of Porobelba, that is why a comparison of ontogeny development of this genus and other damaeid mites is premature.

Setal variability of Hydrozetes lemnae and H. thienemanni (Acari: Oribatida: Hydrozetidae)

Setal variability and the other morphological characters of juvenile stages and adult of Hydrozetes lemnae (Coggi, 1897) and H. thienemanni Strenzke, 1943 were investigated. In the juveniles of both species the length and shape of some setae vary, especially in the gastronotic region, more so in H. lemnae, which is parthenogenetic and reproduces by thelytoky, than in H. thienemanni, which is dioecious. The former species usually has more thick setae in the anterior and medial regions of the gastronotum, especially in the larva, compared to the latter. In the juveniles of H. lemnae the prodorsal setae le and in are longer, and in the nymphs the gastronotal setae of the l-series are usually longer than in H. thienemanni. These species differ distinctly by the number of long setae in the posterior part of the nymphs; in H. lemnae three pairs of long setae occur, while in H. thienemanni only two pairs; the respective juvenile stages of H. lemnae are also smaller than those of H. thienemanni. In the adults the number of c-series setae varies, as seta c1 is lost, and in some individuals also seta c3, and only seta c2 remains.

Morphology of Three European Species of the GenusPunctobibatesBerlese, 1908 (Acari: Oribatida: Mycobatidae)

Abstract. Juvenile stages of Punctoribates punctum (C. L. Koch, 1839) and P. hexagonus Berlese, 1908 are redescribed, those of P. sellnicki Willmann, 1928 are described for the first time, and both juveniles and adults of all species are illustrated. The juvenile stages of these species are similar in body shape and the number of setae on the prodorsum, gastronotum and anal, anogenital and epimeral regions, but differ in the shape and length of some prodorsal and gastronotal setae. Keys to the larvae and nymphs of these species are prepared.