Summary details for Porrhomma microphthalmum (O.P.-Cambridge, 1871)

Distribution

The species is widespread in central and south-eastern England but more scattered elsewhere in England. Apart from scattered records in the south-west, it is absent from much of the west, extending as far north as central eastern Scotland. The species is widespread in north-western and central Europe, but only doubtfully reported for Ireland (Van Helsdingen 1996).

Habitat and ecology

A common spider of agricultural fields (Thornhill 1983) and sparsely vegetated grasslands, such as mudflats and saline grasslands (Meijer 1977). P. microphthalmum is partly subterranean, living between cracks in the soil. However, it may on occasion, be found higher up in vegetation, for example on shrubs. The spider is a frequent aeronaut, which may explain its apparent wide habitat niche as individuals may have been collected on higher vegetation during a ballooning attempt. A Swiss study found that there were two peaks in aeronautic dispersal: the first between July and mid-August and the second between the end of September and mid-December (Blandenier & Fürst 1998). In Britain, Thornhill (1983) found females between January and September and males between March and November. Our data show a peak of adult males in late spring and early summer and females from early to mid-summer, with adults of both sexes occasionally found throughout the year.

Status

The spider is common in the south-east, rare in the north and west. Original author of profile: J.R. Bell Text based on Harvey, P.R., Nellist, D.R. & Telfer, M.G. (eds) 2002. Provisional atlas of British spiders (Arachnida, Araneae), Volumes 1 & 2. Huntingdon: Biological Records Centre.