Arachnologische Mitteilungen
HEFTÜBERSICHT
Heft 34 (2007)
Spiders (Araneae) of the family Oonopidae in the Czech Republic
Spiders (Araneae) of the family Oonopidae in the Czech Republic
introduced species; faunistics; Tapinesthis; Triaeris
Abstract
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.
Ein Beitrag zur Phänologie von Larinioides sclopetarius (Araneae: Araneidae)
A contribution towards the phenology of Larinioides sclopetarius (Clerck, 1757) (Araneae: Araneidae)
abundance; breeding; colonial spider; sex ratio
Abstract
We investigated a colony of Larinioides sclopetarius, the bridge spider, situated at a bridge-like dam in the city of Duisburg, Germany. The study ran from March until October 2004. The mean population density (all size classes) was 26.2 ind./m². The absolute maximum was found in July (71.3 ind./m²). Most of the spiderlings were found from June to October with mean densities up to 30.9 ind./m² in July, indicating that breeding of L. sclopetarius started in summer. Adult males and females occurred in spring, although the highest abundances (up to more than 3 individuals of each sex per m²) were found in summer and autumn. The adult sex ratio averaged over the study period was 1:1.2 (males:females). Some comparisons with other araneids, both solitary and social species, are drawn and discussed.
Spider (Arachnida: Araneae) distribution across the timberline in the Swiss Central Alps (Alp Flix, Grisons) and three morphologically remarkable species
Spider (Arachnida: Araneae) distribution across the timberline in the Swiss Central Alps (Alp Flix, Grisons) and three morphologically remarkable species
Diversity; dwarf-shrub heath; forest; habitat boundary; Meioneta alpica; Metopobactrus prominulus; Pelecopsis radicicola; pitfall traps
Abstract
We collected 6251 adult epigeic spiders from the dwarf-shrub heath to subalpine coniferous forest on Alp Flix (CH, canton Grisons, 1950 m) between May 2005 and May 2006 using pitfall traps. Total species richness and activity density of all species decreased from the open land to the forest, although this pattern varied according to family. The distribution of the 102 species found indicates that the small area around a single tree at the timberline provides habitats for both open land and forest spider species as well as some possible timberline specialists. Five species were new to the canton Grisons: Centromerita bicolor, Centromerita concinna, Hilaira excisa, Meioneta alpica and Tallusia experta. Three species showed remarkable morphological characteristics and were analysed in more detail. We found males of Pelecopsis radicicola without the characteristic longitudinal depression on the raised carapace. It is shown that the males of Meioneta alpica have a considerably variable lamella characteristica, which is nevertheless distinct from the sister species Meioneta ressli. Because we found intermediate forms of the head region described for Metopobactrus prominulus and M. schenkeli, respectively, M. schenkeli is considered a syn. nov. of M. prominulus. This study shows that the known distribution and taxonomic status of various spider taxa in the Central Alps are still incomplete and further work on arthropods in remote areas should be strongly encouraged.
Notes on Cesonia, a newly recorded genus for the Asian spider fauna (Araneae, Gnaphosidae)
Notes on Cesonia, a newly recorded genus for the Asian spider fauna (Araneae, Gnaphosidae)
Anatolia; Cesonia aspida; spider; Turkey
Abstract
The spider species Cesonia aspida Chatzaki, 2002, together with its genus Cesonia Simon, 1893, was found in Anatolia (Turkey) and represent new records for the Asian spider fauna. Its characteristic features, drawings of genitalia, a photograph of the general habitus and a distribution map for Eurasia are presented.
An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones)
An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones)
aggregation; alien species; behaviour; central Europe; introduced species; invasion strategies; taxonomy
Abstract
Since about the year 2000 a hitherto unidentified species of the genus Leiobunum C. L. Koch, 1839, has rapidly invaded central and western Europe. Records are known from The Netherlands (probably the country of first occurrence in Europe), Germany, Austria and Switzerland. This introduced species, until now, mainly inhabits walls of buildings and rocky environments. Adults characteristically aggregate during daytime into groups of up to 1.000 individuals. The species is described and details on its present distribution, habitat preference, phenology and behaviour are presented.