Summary details for Micaria subopaca Westring, 1861

Distribution

The species is almost confined to the south of England. It has also been found in Stirlingshire, and in Glasgow and Liverpool, but in view of the distance from its main centre of population in the south, there must be some doubt as to whether these northern records represent well-established populations or are chance importations. It is widespread in northern and central Europe.

Habitat and ecology

M. subopaca occurs mainly on trunks of pine trees, but has also been found at the base of oak trees and on railings. It is an ant-mimic, often found in company with ants, running on pine trunks in sunshine. Both sexes are adult from May to October.

Status

The spider can be fairly numerous on pine trees in a number of places in the south of England, but records indicate an apparent decline. The isolated northern records may represent temporary colonies formed by accidental introductions, and it remains to be seen whether they will persist and whether other northern populations will be found.

Threats

Threats include the loss of old trees in sunny situations and the loss of heathland to development or seral succession.

Management and conservation

Old trees in sunny situations should be retained and seral succession prevented from shading existing trunks. Text based on Dawson, I.K., Harvey, P.R., Merrett, P. & Russell-Smith, A.R. (in prep.).