This species displays strong sexual dimorphism: The male is black and shiny with a narrow abdomen that often has two white spots, and with a body length (excluding legs) of around 5 mm; The female is slightly larger with a much plumper, slivery abdomen bearing a leaf-shaped black mark.

Microlinyphia impigra is similar but females have thinner dark cardiac mark. Males usually lack the abdominal white patches seen on M. pusilla.

This species spins a horizontal sheet web in low vegetation in a wide range of habitats including heathland, but is perhaps commonest in grassland.

Both sexes are mature in spring and summer, with a peak from early to mid-summer, individuals occasionally persisting into the autumn.

The species is widespread in much of Britain.

Fairly frequent in Leicestershire and Rutland.

4036 British records to Jan 2013