obituary, Herbert Casemir, aftermath

request

anniversary, Peter Weygoldt

editorial

Balkan populations of Rafalskia olympica (Kulczyński, 1903) are distinguished as separate subspecies Rafalskia olympica bulgarica Staręga, 1963 nov. stat.. Certain novel details of the R. olympica female body structure are presented. It is stated that Metaplatybunus drenskii Šilhavý, 1965 in not a synonym of R. olympica.

We collected spider communities of oak trees in a Bavarian forest (Germany) by insecticidal knockdown fogging and investigated how communities changed on trees where predacious Formica polyctena ants were dominant. Spider communities of 'ant-trees' harboured significantly more spiders, mostly juveniles, and were different in familial- and species composition. In particular, Clubionidae, Salticidae, Araneidae and Linyphiidae were sampled in higher abundances from trees with ants. In contrast, lower numbers of Theridiidae (mostly Enoplognatha ovata) and Anyphaenidae were collected. Within Linyphiidae, which dominated all communities in terms of individuals and species numbers, Linyphia triangularis (only juveniles) was found in much higher numbers on oak trees with ants.

The peat bog in Dubravica is of spread interest due to ist overgrowing by the process of natural succession, causing the habitat to become dryer and shadier. The dominance structure and phenology of wolf spiders on the Dubravica bog was studied. The spiders were collected during the period 09.04.-9.10.1995, using 20 pitfall traps. Altogether 10 lycosid species were found among 723 adult individuals. For six more abundant species phenology graphs are presented. Three species are found to be eudominant: Pardosa lugubris, Trochosa spinipalpis and Hygrolycosa rubrofasciata. The lycosids habitat preferences and dominance structure according the habitat condition and species occurences on some other European bogs are discussed. 55,2 % caught specimens are hygrophilous species, and only 7,6 % are photophilous. The lycosid fauna and dominance structure does reflect the habitat condition. As overgrowing is not fully progressed yet, the lycosid fauna of this bog is still relatively bog-characteristic.

In 1996 and 1997, spiders were collected by means of tree eclectors on standing dead tree trunks in floodplain forests in South Moravia (Czech Republic). Trunk communities on two sites differing in their exposure to floods were studied. In 1997, one of the sites was struck by a severe summer flood. Of 1714 individuals collected, 924 adults and 50 juveniles were identified to species. 82 species of 17 families were found. The dominant families both in terms of individuals and species were Linyphiidae and Theridiidae. 41 of the present species are considered obligate to facultative arboricolous ones. 13 species were new finds for the study area (extended Pálava Biosphere Reserve). Tmarus stellio was the first record for the Czech Republic, Midia midas the first one for Moravia. More species and individuals were collected on the flood-exposed site, particularly in 1997 with a peak at the time of the summer inundation (Oedothorax retusus made up for 97 % of adults during this period). A number of rare species was found and some comments regarding their distribution in the Czech Repubic, range and habitat are made.

It is described, how an adult female of Scotophaeus scutulatus killed an also adult female of Tegenaria atrica in the web of the latter species. According to published and unpublished data, a web-invading behaviour is known in 4 gnaphosid species (Poecilochroa senilis, Poechilochroa pugnax, Scotophaeus blackwalli, Taieria erebus), an araneophagic behaviour is also known in 4 species (Drassodes lapidosus, Poecilochroa senilis (auspex), Scotophaeus scutulatus, Taieria erebus). the question, wether these behaviour patterns are typical for soil-dwelling gnaphosids, remains open until further observations and investigations.

book review: Harvey, Peter R., David R. Nellist & Mark G. Telfer (eds.): Provisional Atlas of British Spiders (Arachnida, Araneae), Volumes 1 & 2.

congress report

The spider fauna of the epigeic and the shrub stratum of a thermophilic wood edge in Bavaria (Germany)

Remarks on the rediscovery of two "lost" species and on one first record of a spider species in Brandenburg

An anomaly of chaetotaxy of pedipalpal chela in Neobisium carcinoides (Arachnida: Pseudoscorpiones)

It has been widely accepted that the biology of Drapetisca socialis includes a pronounced stratum change of this species from the forest soil into the crowns of beech trees. On old pine trees, however, D. socialis never exceeded its activity range to heights greater than 10 metres. These results lead to an re-examination of existing results, and to a review of several studies on tree-dwelling spiders. A synopsis of all data revealed that D. socialis changes stratum along stems of trees into greater heights in forests, but only very seldom, and then obviously only by chance, reaches high tree crowns. Earlier results of a stratum change into the crowns of old beech are only assumptions. The requirement for studies including samples from the bottom to the top of trees is proposed.

In contrast to social spider webs aggregative spider webs are defined as incidental and non-functional. Three new records of large (3-10 meter) aggregative spider webs in Germany are presented. In one case (cut fir tree) 11 spider species were recorded from the same web. Two main reasons for the occurence of large aggregative webs are hypothesized: 1. Optimal (weather) conditions for ballooning behaviour may cause a mass occurrence of spiders, which are able to cover vegetation structures with their draglines. 2. Disturbances in the spider habitat (e.g. cutting trees) may cause a movement of spiders to higher (then absent) strata, which may cover also vegetation with huge webs. In both cases spiders may aggregate on the surface of vegetation structures and webs are more dense at their higher points. A parasocial aggregation cannot be excluded, but according to the new observations this seems to be unlikely.

Specimens of T. vulgaris were recently introduced in Germany with cricket boxes from southern United States. The species has been sent within Germany with post packages to different pet dealers. These samples represent probably the first confirmed records of T. vulgaris for Germany. Further observation could show, whether the populations are stabile in synanthropic habitats, especially inside bulidings. Female genitalia are illustrated. One structure is recognized as a glandular part of the spermathecae. Terminology of female genitalia is given in comparison of terms used in the past by different authors.

Spider of the year 2001 and 2002: Argiope bruennichi and Pisaura mirabilis