Formica cunicularia Latreille, 1798

Description and notes

This species was taxonomically confused as a variety of Formica fusca L. or as a synonym of F. rufibarbis until revised by Yarrow (1954). Formica cunicularia includes two variety names of F. fusca: vars. glebaria and rubescens given to workers which are not entirely black as is typical of F. fusca, but which have some red on the sides of the head (glebaria) or with reddish legs and thorax as well (rubescens). They are clearly not as shiny black when compared with F. fusca and are distinguished from F. rufibarbis by having not more than two (usually none) prothoracic hairs.


Southern England, becoming rare north of latitude 52°. Channel Islands.

Status (in Britain only)

This species is not regarded as being scarce or threatened.


Prey is collected, but many flying insects are brought in and these are presumably found already dead. Flowers (especially Apiaceae) and extrafloral nectaries are visited. Donisthorpe (1927) records a subterranean aphid with this species, but foraging is typically above ground.

Habitat and nest sites

Shade intolerant (see Pontin 1996) and most abundant on coastal sites. Also on heaths and downland with no clear preference for soil type, but south-facing slopes or small mounds are preferred. Plants with aphid populations above ground are valuable, otherwise vegetation type is not critical provided bare ground or stones are available to nest under. In moderately tall grass, earthen mounds are constructed for solaria and nests can be moved easily if warmer sites are available. Nest distribution is usually away from heavy grazing.

Reproductive behaviour

Sexuals are present in nests during July and often August, frequently only one sex in a nest. This is typical of Formica and some other genera and may be an adaptation for cross-mating. I have no records of mating in F. cunicularia, but it is likely to be similar to that of F. rufibarbis, where females ‘call’ males and mating occurs near the tops of plant stems when the temperature rises at around 10.00 hours.

Author of profile

J Pontin.

Year profile last updated