Among animal constructions, spider’s orb webs represent regular geometrical architecture models. Their construction is the result of successive, simple and reproducible behavioural patterns, often considered as stereotyped. It has recently been shown that spider’s building behaviours vary, which can alter web regularity. The final capture spiral results from the laying of successive threads between two radii, here termed ‘spiral units’. We defined a theoretical normal web, as a web in which each turn of the final spiral should be parallel to the preceding one. Weaving of the spiral units sometimes leads to anomalies in the orb web. Anomalies were identified and analysed in the orb-weaving spider Zygiella x-notata (Clerck, 1757). From video recordings of web construction, we noted the displacements of the legs and of the abdomen of the spider. We compared the frequency of displacements, and their duration, between the construction of spiral units that produce a normal turn and ones that produce an anomalous turn. The position of the legs on the web’s threads was also analysed. Results showed that anomalies were not the consequences of a modification in activity but more likely the result of the position on the radii of the fourth leg. These results suggest that spiders use local information to build the final capture spiral.

Spiders leave draglines, faeces and other secretions behind when traveling through their microhabitat. The presence of these secretions may unintentionally inform other animals, prey as well as predators, about a recent and possible current predation risk or food availability. For a wolf spider, other spiders including smaller conspecifics, form a substantial part of their prey, and larger wolf spiders, again including conspecifics, are potential predators. We tested two hypotheses: that large wolf spiders may locate patches of potential spider prey through the presence of silk threads and/or other secretions; and that prey spiders may use secretions from large wolf spiders to avoid patches with high predation risk. We used large (subadult or adult) Pardosa saltans to provide predator cues and mixed dwarf spiders or small (juvenile) P. saltans to provide prey cues. Subadult wolf spiders were significantly attracted to litter contaminated by dwarf spiders or small conspecifics after 6 hours but no longer after 24 hours. In contrast, neither dwarf spiders nor small P. saltans showed significant avoidance of substrate contaminated by adult P. saltans. However, small P. saltans showed different activity patterns on the two substrates. The results indicate that wolf spiders are able to increase the efficiency of foraging by searching preferentially in patches with the presence of intraguild prey. The lack of a clear patch selection response of the prey in spite of a modified activity pattern may possibly be associated with the vertical stratification of the beech litter habitat: the reduced volume of spaces in the deeper layers could make downward rather than horizontal movement a fast and safe tactic against a large predator that cannot enter these spaces.

The maintenance of polymorphism within populations may be the consequence of several elements of species life history such as use of space, activity rhythms, predation, parasitism and reproduction. The present study focuses on the latter aspect using an orb weaving spider, Agalenatea redii, which presents five different morphs of the opisthosoma pattern in the adult stage. Over the course of four years, from 2008 to 2011, adult spiders (males, females and pairs) were observed at different sites. In 2011, we also conducted a six-week survey of a single population, observing the number of spiders of each morph and the morph of paired spiders. We collected field data on the spatial and temporal distribution of spiders based on their sex and morph. Using a distance analysis, we compared the field distribution with a simulated one in which pairs were associated at random. The results showed that although there were changes over time and space in the proportions of females of the different morphs, as well as in the proportion of the pair associations, pairing according to morphs probably occurs at random.

The spider fauna of buildings and other urban habitats (city parks, green areas of industrial enterprises, and housing estates) of Chernivtsi city was surveyed. In the period 2002-2011, 212 species belonging to 26 families were recorded. Previous studies found a total of 173 species of spiders belonging to 26 families from the territories which are now included in the city limits of Chernivtsi. Currently, the total spider species list for Chernivtsi includes 260 species of 30 families, of which 125 species (21 families) were recorded both by earlier researchers and by ourselves. The most important reasons for changes in urban spider assemblages are as follows: species habitat change, introduction of alien species, and description of new species unknown in the late 19th – early 20th centuries.

A total of 107 spider species from 15 families were recorded in the herbaceous vegetation of the steppe ecosystems of Ukraine and the Central Chernozem region of Russia. Araneidae, Thomisidae, Salticidae and Theridiidae were the most species-rich. The species composition depended on the steppe type; adjacent forest habitats influenced steppe fauna in the forest-steppe and northern part of the steppe natural zone. The number of generalist, forest and wetland dwelling species in the steppe vegetation showed a tendency to decrease towards the south. Dominance of herb-dwelling spiders was specific to each steppe type; no single species was found to predominate in all the steppe habitats.

A female specimen of the cribellate spider species Badumna longinqua (L. Koch, 1867) was found in a 'do-it-yourself-store' in Berlin. The species is of Australian origin and has been introduced into New Zealand, Japan, Uruguay and California. This is the first record of a representative of the family Desidae from Europe. B. longinqua lives in and around houses and is apparently capable of establishing itself in Europe.

The pseudoscorpion Dendrochernes cyrneus (L. Koch, 1873) is recorded for the first time in Brandenburg (Germany). The specimen was found in the ancient park of Sanssouci under the bark of a branch of a beech tree. The suitability of D. cyrneus as an indicator species for old-growth woodlands is discussed.

This paper presents new data, characteristic features, standard body measurements and illustrations of the rare European linyphiid spider Glyphesis taoplesius Wunderlich, 1969; which is recorded here for the first time in Slovakia. The species was found with high abundance in pitfall traps exposed in a floodplain forest near a water reservoir in the lowland Podunajská rovina.

book review: Jörg Wunderlich (Ed.) (2011): Extant and fossil spiders (Araneae). Heutige und fossile Spinnen.

Reply to the book review by Y. Marusik on „Jörg Wunderlich (Ed.) (2011): Extant and fossil spiders (Araneae). Heutige und fossile Spinnen“

obituary, bibliography, Franz Ressl

Trogulus banaticus Avram, 1971 is characterised and recorded as new for Slovenia. This species was previously mistaken for T. coriziformis C. L. Koch, 1839 and T. graecus Dahl, 1903 which were later rejected from the Slovenian fauna. T. banaticus is compared with the similar, and partly sympatric, T. tingiformis C. L. Koch, 1847 with which it has often been confused. A table of distinguishing characters for both species is provided, and the ecology of T. banaticus and its general distribution are discussed.

First records of the synanthropic spiders Steatoda grossa for Saxony as well as Nesticodes rufipes and Uloborus plumipes for Mecklenburg-Western Pomerania (Araneae, Theridiidae, Uloboridae)

The pseudoscorpions Chthonius (Chthonius) carinthiacus Beier, 1951 and Chthonius (Ephippiochthonius) tuberculatus Hadži, 1937, are recorded for the first time from Slovakia. An illustrated description of these species is provided based on their morphological and morphometric characters. The descriptions of the species offer an update on the variability of their morphological and morphometric characters.

The epigeic spider fauna in a partially abandoned quarry in Bad Deutsch-Altenburg/ Donau (Austria: Lower Austria) was examined. Six study sites at different stages of abandonment were sampled using pitfall traps in a period from 27 March to 29 October 2006. In total, 79 species were caught comprising 845 adult individuals from 18 families. Twenty-eight species were classified as Red list taxa according to the Red lists of the Czech Republic and/or Slovakia. The poorly-known spider species Thanatus pictus L. Koch, 1881 and Xysticus embriki Kolosváry, 1935 are presented in more detail. Comparison of the six spider assemblages in the quarry with 16 geographically adjacent spider assemblages in the area of the “Parndorfer Platte” shows a clear succession within the ruderal study sites. These begin with the most recent to the oldest site, and continue to well-managed dry grasslands, further developing to scrub grasslands and hedges, and eventually to natural forests in the region.

congress report

congress report

European Spider of the Year 2012