Summary details for Porrhomma convexum (Westring, 1851)

Distribution

P. convexum is widespread but scattered in much of England and Wales, but widely scattered elsewhere. A Palaearctic species widespread in north-western and central Europe.

Habitat and ecology

Typically this spider is found within damp mines and caves where it constructs a small web within recesses in the rock. P. convexum can also be found in damp culverts, cellars, beneath rock piles, amongst thick undergrowth and within sewage filter beds (Crocker & Daws 1996; Locket & Millidge 1953; Bristowe 1958). Adults may be found throughout the year. Single egg-sacs are affixed to the rock surface and have been noted in November.

Status

The species may have suffered long-term decline throughout its range, but may be frequent where it does occur. Some older records may have been misidentified.

Threats

Given the apparent broad range of subterranean habitats utilised by this species, it is difficult to understand the reason for its apparent recent decline.

Management and conservation

Further research is needed to determine the micro-habitat requirements and ecology of this species. Until this is undertaken, destruction or disturbance of the subterranean habitats where it occurs, natural and man-made, should be prevented. Text based on Dawson, I.K., Harvey, P.R., Merrett, P. & Russell-Smith, A.R. (in prep.).