Lasius alienus (Foerster, 1850)

Description and notes

Lasius alienus is a small brown to dark brownish ant. The scapes and tibia have no erect hairs. Workers can be separated from the sibling species L. psammophilus Seifert by having no more than two hairs (0-2) between the propodeal spiracle and the metapleural gland.


Most records are from southern and central England with a few records from Wales and Scotland. It seems to be widely distributed in Britain but absent from Ireland, although previous confusion with L. psammophilus means that it is currently under-recorded.
There are records from Spain to Kazakhstan and in Scandinavia to 55.3°N.

Status (in Britain only)

This species is not regarded as scarce or threatened.


It prefers warm dry habitats such as chalk grasslands. On sand and gravel substrates it is usually replaced by L. psammophilus.

Flight period

July to September.

Foraging behaviour

Tends both underground and tree-dwelling aphids and feeds on their honeydew.

Nesting biology

Nests are usually in soil and under rocks.

Author of profile

M G Fox

Year profile last updated