Invasive alien species in Switzerland - Schweizer ...

An inventory of alien species and their threat to biodiversity and economy in Switzerland FOEN 2006 108
have become established, and from German cities, where stable populations of
Holocnemus pluchei (Scopoli) have been found (Jäger, 1995, 2000).
Interestingly, in contrast to the expanding nature of many house-dwelling species, the
false scorpion Chelifer cancroides (L.) seems to be decreasing in abundance, although
the distribution and population sizes of this group are very poorly investigated in
Switzerland, especially in synanthropic areas. Apparently, the increased hygiene and
the changed climate in houses caused by central heating affects this species. The
considerable alteration in temperature, and changes in daily temperature and humidity,
might favour some species, especially species adapted to a warm environment, and
negatively affect others.
5.5 Greenhouse-inhabiting species
> Hasarius adansoni (Audouin) is a cosmopolitan species, which is widespread in
European greenhouses (Simon, 1901; Holzapfel, 1932; König and Pieper, 2003).
Records from Switzerland are summarized by Hänggi (2003). Information on synanthropic
spiders in general, and this species in particular, is too limited to come to any
conclusion about the status of species, e.g. whether populations are increasing.
> Uloborus plumipes Lucas is another greenhouse species, but is much more common
than the species above (Jonsson, 1993, 1998; Thaler and Knoflach, 1995). However,
misidentifications in some records arising from confusion with the congeneric
U. glomosus (Walckenaer) cannot be ruled out.
> The first record of Coleosoma floridanum Banks in Switzerland was reported by
Knoflach (1999) from the tropical greenhouse of the Old Botanical Garden at Basel.
This pantropical species is occasionally reported from greenhouses in Europe
(Hillyard, 1981; Broen et al., 1998; Knoflach, 1999). However, its status cannot be
evaluated yet.
> Eperigone eschatologica (Crosby) was first recorded in Europe from Germany and
Belgium ( see Klein et al., 1995; Bosmans and Vanuytven, 1998) but very recently it
was found in Switzerland in a private flat, most probably carried on a plant from a
German garden centre (Hänggi, unpubl.). It remains to be seen whether it will become
established in greenhouses in Switzerland.
> Heteropoda venatoria (L.), a member of the family Thomisidae (crab spiders) of
South-east Asian origin, was repeatedly reported from heated buildings, e.g. in zoos
(Jäger, 2000). Surveys and research on the spider faunas of heated buildings and
greenhouses would be a useful exercise, since this species is also able to penetrate
human skin (c.f. Zoropsis spinimana).
> Thanatus vulgaris Simon, a Mediterranean sister species of the native T. atratus
Simon, would most probably be found in Swiss greenhouses if an intensive survey
were undertaken (see Jones, 1997; Jäger, 2002).