Changes in epigeic spider community in primary succession on a brown-coal dump

A descriptive model of primary succession of spiders on a brown-coal dump is presented. Multivariate methods (cluster analysis and detrended correspondence analysis), and community indexes were applied to evaluate changes in community composition of epigeic spiders. Two different rehabilitation age stages were investigated. The cluster analysis helped to determine a case of horizontal asynchronous succession. The DCA was able to distinguish divergent trends of succession from the initial stage. Successional trends in species replacements were observed. In all aspects of succession there was found to be directional towards a "ruderal steppe" subclimax

Orchestina pavesii (Simon, 1873), an oonopid spider new to Slovakia (Araneae: Oonopidae)

Representatives of Oonopidae are tiny spiders, usually of a pale colour, with 6 oval eyes. Systematically, they belong to Dysderoidea, which include about 120 genera (CODDINGTON & LEVI 1991), but Oonopidae, alone, include 51 genera and more than 70 species (PLATNICK 1989). They are distributed all over the world, except for Antarctica, but most of the species come from the tropics. In Europe, there are 6 genera of oonopid spiders, represented by about 20 species (PLATNICK 1989). But only 6 species have been known from the Central Europe until recently (NENTWIG 1991). In Slovakia, only 2 species of oonopid spiders, Oonops domesticus Dalmas, 1916 and Triaeris stenaspis Simon, 1891, have been recorded so far (GAJDOS et al. 1999)

Spiders (Araneae) of the family Oonopidae in the Czech Republic

The oonopid spiders (Oonopidae) Tapinesthis inermis (Simon, 1882) and Triaeris stenapis Simon, 1891 are recorded for the Czech Republic for the first time. T. inermis was redetermined from misidentified material and T. stenaspis was discovered in a greenhouse

Stenochrus portoricensis new to the Czech Republic (Schizomida, Hubbardiidae)

A schizomid, Stenochrus portoricensis Chamberlin, 1922 (family Hubbardiidae), was collected in a greenhouse in Brno. This is the first discovery of a schizomid from the Czech Republic

Use of conditional prey attack strategies in two generalist ground spider species

Generalist predators have evolved a variety of behavioural adaptations in prey capture to effectively subdue different prey types. Such predators use a conditional hunting strategy. Among spiders, representatives of Gnaphosidae are known to use either venom attack (subduing prey with venom) or silk attack (subduing prey with silk). In this study, we aimed to test the hypothesis of the conditional use of prey capture strategy (venom versus silk attack) in two species, Drassodes sp. and Zelotes sp. We also measured the size of their venom glands and the number of their piriform glands in order to reveal whether behavioural adaptations are paralleled with morphological ones. As prey, we used other spiders of variable sizes as these are considered dangerous prey. We found that Drassodes used mainly silk attack, while the majority of Zelotes used venom attack. The probability of using silk attack increased with predator/prey body length ratio in Drassodes, but not in Zelotes. Then, we disabled silk use in individuals of both species. All disabled Drassodes used venom attack, but about half of individuals attempted to use silk attack first. All Zelotes used venom attack, and none attempted to use silk attack first. We found significantly larger venom glands in Drassodes than in Zelotes, while the number of piriform silk glands was similar. The behavioural adaptations are, thus, not paralleled with morphological (i.e., venom and silk gland size) ones. Our results suggest that both Drassodes and Zelotes can use both attack strategies with similar efficacy

Zoologische Staats-sammlung, Münchhausenstr. 21, 81247 Munich, Germany 3 Eben 21, 4202 Kirchschlag, Austria 4 Agricul-ture and Agri-Food Canada

Abstract Calymmochilus dispar Bouček & Andriescu (Hymenoptera, Eupelmidae) and Gelis apterus (Pontoppidan) (Hymenoptera, Ichneumonidae) are newly recorded as parasitoids of the ant-eating spider Zodarion styliferum (Simon) (Araneae, Zodariidae). The larvae of both parasitoid species fed on juvenile spiders. The final instar larva and pupa of C. dispar and the male of G. apterus are described for the first time. Both species represent new distribution records for Portugal. The biology and host associations of the parasitoids are discussed

A Parasitoid Wasp Induces Overwintering Behaviour in Its Spider Host

Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria performed species-specific manipulation of theridiid spiders, Neottiura bimaculata and Theridion varians, shortly before pupation. Parasitized N. bimaculata produced a dense web, whereas parasitized T. varians built a cupola-like structure. The larva pupated inside of either the dense web or the cupola-like structure. We discovered that unparasitized N. bimaculata produce an analogous dense web around their eggsacs and for themselves during winter, while T. varians construct an analogous ‘cupola’ only for overwintering. We induced analogous manipulation in unparasitized hosts by altering ambient conditions. We discovered that the behavior evoked by larvae in two hosts was functionally similar. The larva evoked protective behaviors that occur in unparasitized hosts only during specific life-history periods

Changes in epigeic spider community in primary succession on a brown-coal dump

A descriptive model of primary succession of spiders on a brown-coal dump is presented. Multivariate methods (cluster analysis and detrended correspondence analysis), and community indexes were applied to evaluate changes in community composition of epigeic spiders. Two different rehabilitation age stages were investigated. The cluster analysis helped to determine a case of horizontal asynchronous succession. The DCA was able to distinguish divergent trends of succession from the initial stage. Successional trends in species replacements were observed. In all aspects of succession there was found to be directional towards a "ruderal steppe" subclimax

Spiders (Araneae) of the family Oonopidae in the Czech Republic

The oonopid spiders (Oonopidae), Tapinesthis inermis (Simon, 1882) and Triaeris stenaspis Simon, 1891, are recorded for the Czech Republic for the first time. T. inermis was redetermined from misidentified material and T. stenaspis was discovered in a greenhouse

Comparison of the mean density of web in parasitised and unparasitised <i>N. bimaculata</i> spiders.

<p>Whiskers are standard errors of the mean.</p