Tomasz Marquardt

Ovoviviparity in Macrocheles glaber (Müller) (Acari: Macrochelidae), with notes on parental care and egg cannibalism

In Macrocheles glaber (Müller), oviposition can involve either oviparity or egg production followed by immediate hatching of the larva, a process that may be called ovoviviparity. We observed three phases in the process of ovoviviparity: preoviposition behaviour, oviposition followed by holding the egg under the gnathosoma and hatching of the larva assisted by the female. Two factors appear to favour the occurrence of ovoviviparity in this species: poor feeding and poor substrate quality. We witnessed egg cannibalism four times in two of the four females that we observed. We discuss the consequences of variable oviposition strategy, parental care and egg cannibalism in M. glaber in the context of maximization of reproductive success.

Continuous recording of soil mite behaviour using an Internet Protocol video system

Behavioural studies on tiny animals require methods that are relatively inexpensive, can be easily monitored and provide high-quality data. Recently, digital tools such as Internet Protocol (IP) cameras and video surveillance systems have become less expensive, creating new possibilities for behavioural studies. The best system of observation from the researcher’s point of view works continuously without human assistance and records behavioural data for further multiple analyses. Here we describe the system used for studies on mesostigmatid soil mites in Department of Zoology, Kazimierz Wielki University in Bydgoszcz.

Contribution to the diversity of soil mites (Acari, Gamasida) in southern Croatia (Dalmatia), with some ecological and zoogeographical notes

Contribution to the diversity of soil mites (Acari, Gamasida) in southern Croatia (Dalmatia), with some ecological and zoogeographical notes The species diversity of soil gamasid mites (Acari) in southern Croatia (Dalmatia) was studied in August 2002. In the Krka National Park, Brač Island, and near the town of Makarska, 320 samples were collected from various microhabitats: soil, grass and moss ground cover, wet moss, needle litter, moss covering tree trunks, and decaying wood). Altogether, 2097 mites of 56 gamasid species were recorded. Dominant species were: Polyaspis patavinus (Brač Island), Zercon fageticola (Makarska), and Cheiroseius serratus (Krka National Park). Analyses of ecological preferences and zoogeographic distribution were made for Polyaspis patavinus, Cheiroseius serratus, Zercon fageticola, Z. berlesei, Z. athiasi, Asca nova and A. aphidioides.

Mating behaviour of Trichouropoda ovalis (Acari: Mesostigmata: Uropodina: Trematuridae) with notes on phylogeny of reproductive biology in the Parasitiformes

Reproductive biology of mites is diverse and of phylogenetic importance. Here, we describe the mating phases of Trichouropoda ovalis (C.L. Koch, 1839) and discuss them in the context of known mating sequences of Parasitiformes. Mites were observed using IP (internet protocol) video camera. We identified six phases of mating in T. ovalis. In T. ovalis we found that: (1) mating initiation, formation of spermatophore, and transfer using male’s chelicerae, were similar to that described for other Parasitiformes; (2) similar to most of the parasitiform mites, specimens assumed venter-to-venter position during mating. Then their bodies were repositioned and ventral sides were set up at an angle to provide sufficient space for growing of the spermatophore, as found only in one uropodine species so far; (3) time of spermatophore formation was considerably shorter than in other uropodine taxa, but similar to some of other parasitiform mites studied up to now; (4) time of spermatophore transfer and semen uptake time (sperm pumping) were shorter, compared to other Uropodina studied till now; and (5) semen uptake mechanism differed from other uropodine taxa because of use of ventral side pressing of both mating specimens, while other Uropodina use epigynial movements or palps/chelicerae during sperm pumping. The use of unspecialized chelicerae during spermatophore transfer in Uropodina was confirmed, which suggests that this behaviour is a plesiomorphic character of Parasitiformes.

Diversity of soil mite communities (Acari) within habitats seasonally flooded by the Vistula River (Ostromecko, Poland)

Abstract The research was carried out in three types of habitats located in the seasonally flooded area of the Vistula River within Wielka Kępa Ostromecka Reserve: Salicetum albo-fragilis, Fraxino-Alnetum and Populetum albae. In the soil of Salicetum albo-fragilis Veigaia nemorensis and Trichouropoda ovalis were abundant, while Fraxino-Alnetum was dominated by Rhodacarellus silesiacus, and Populetum albae was overwhelmed by Rhodacarellus silesiacus and Dinychus inermis. Only between the Mesostigmata communities populating Fraxino-Alnetum and Populetum albae there were no statistically significant differences recorded in the distribution of abundance. The most similar, from the qualitative, quantitative and qualitative-quantitative point of view were Mesostigmata communities inhabiting Fraxino- Alnetum and Populetum albae. The numerous occurrence of Rhodacarellus silesiacus population in the soil of Fraxino-Alnetum and Populetum albae is most probably the result of succession changes within those habitats, and the species itself can be seen as an indicator of those habitats undergoing the process of a riparian forest transforming into an oak-hornbeam forest vegetation type.

Pre-ovipositional and ovipositional behaviour of Lasioseius ometes (Oudemans) and Hypoaspis kargi Costa (Acari: Dermanyssiae: Ascidae, Laelapidae) with notes on egg protection strategies in Mesostigmata

ABSTRACT Egg deposition by the soil mites Lasioseius ometes (Oudemans, 1903) and Hypoaspis kargi Costa, 1968 was observed using continuous video-monitoring. The process in both species was found to consist of four distinct phases. In Phase 1, both species engage in pre-ovipositional activity prior to the egg being extruded from the genital opening. In L. ometes, the female often selects a substrate depression for egg laying and examines the depression carefully with the gnathosoma and legs I before oviposition. In H. kargi, egg deposition sites are chosen without regard for substrate depressions. Phase 1 lasted approximately 3 minutes for both species. Phase 2 involved egg extrusion and holding of the egg beneath the gnathosoma. Phase 2 lasted approximately 20 times longer in L. ometes (5 minutes) than in H. kargi. Alteration of the egg surface in the form of thorn-like outgrowths was recorded in L. ometes. Egg deposition occurs in Phase 3, and in L. ometes the egg is generally placed at the deposition site using the chelicerae. Hypoaspis kargi also uses the chelicerae for egg manipulation, but also adjusts orientation of the egg with legs I. The sticky nature of egg surface in H. kargi may provide a means for the female to effectively cover the exposed egg with a protective layer of soil particles. Egg deposition in both species occurred in less than 90 seconds. Phase 4 involves egg covering, but behaviour of the female during this last phase differs markedly between the two species. In L. ometes, the female tends to remain close to the egg, whereas in H. kargi the female moves away from the egg to search for substrate particles appropriate for its covering. The average time for Phase 4 in H. kargi was approximately four times longer (80+ minutes) than in L. ometes.

Morphological ontogeny of Protoribates dentatus (Acari, Oribatida, Haplozetidae)

Abstract The morphological ontogeny of Protoribates dentatus (Berlese, 1883) is described and illustrated. The juveniles of P. dentatus are elongated, oval in cross section, and their prodorsal, gastronotal setae and most setae on the legs are thin, smooth or with short barbs, which is typical of xylophages. Typical for this group is also a posterior position of the anal opening and relatively thick leg segments and claws, especially on leg I. The larva of P. dentatus has 11 pairs of gastronotal setae, including h2; and setae c2, la and lm are with excentrosclerites. The nymphs have 15 pairs of setae, of which c2 l- and h-series are with excentrosclerites. The adult of this species has a long seta ad1 (which is short in most congeners) and the number of claws varies on all leg tarsi.

Morphological ontogeny of Minunthozetes pseudofusiger (Acari, Oribatida, Punctoribatidae) and comments on Minunthozetes Hull

Abstract The morphological ontogeny of Minunthozetes pseudofusiger (Schweizer, 1922) is described and illustrated. The juveniles of this species have a humeral organ and a gastronotal shield which bears four pairs of setae in the larva (dm, dp, lp, h1) and 10 pairs in the nymphs (d-, l-, h-series, p1). The larva has 12 pairs of gastronotal setae, including h3, whereas the nymphs have 15 pairs. Setae of c-series are inserted on unsclerotized integument in all juveniles. Solenidion ω2 on tarsus I is longer than ω1 and situated anteriorly to ω1 in the nymphs and adult stage, as in most species of Melanozetes Hull, 1916.

Morphological ontogeny of Heptacarus hirsutus (Acari, Oribatida, Lohmanniidae), with comments on Heptacarus Piffl

Abstract The morphological ontogeny of Heptacarus hirsutus Wallwork, 1964 is described and illustrated. All instars of this species have two pairs of exobothridial setae, which is characteristic for the lower Oribatida. They have strong chelicerae, anal opening in a posteroventral position, and thick legs I and II, features which are typical for xylophagous mites. The larva has 34 gastronotal setae, including inguinal h4, a striking feature of the lower Oribatida, this stage has also a long, cudgel-shaped Claparèdes organ. In the next instars of H. hirsutus, a strong hypertrichy occurs on the posterior part of the hysterosoma, and the number of setae increases in the protonymph, deutonymph, tritonymph and adult to about 60, 75, 95 and 115 setae, respectively. In the deutonymph, tritonymph and adult of H. hirsutus, the ano-adanal plate is incompletely fussed.

Morphological ontogeny of Diapterobates altaicus (Acari: Oribatida: Ceratozetidae), with comments on Diapterobates Grandjean

Abstract The morphological ontogeny of Diapterobates altaicus Bayartogtokh, 2010 is described and illustrated. The juveniles of this species are unpigmented, except for a dark sclerite around a gland opening on the hysterosoma. In the larva, most gastronotal setae are of medium size, except for longer c3, dp, lm, lp and h1, whereas in the tritonymph, all gastronotal setae are long, especially c3, dp, lp, h-series and p1. In all juvenile stages, a humeral organ is present. The adult of D. altaicus has setae bv″ and v″ on femur I clearly shorter than seta d.