Strongylognathus testaceus (Schenck, 1852)

Description and notes

Strongylognathus testaceus is a very rare ant parasitic on Tetramorium caespitum (Linnaeus). It is thought to be a degenerate slave-maker. Workers are yellowish brown, have pronounced occipital emargination and toothless sickle shaped mandibles.


Very local in Devon, Dorset, and S. Hants.

In Europe present from the Pyrenees to Western Siberia and Sweden to North Italy.

Status (in Britain only)

This species is listed by Shirt (1987) and Falk (1991) as Rare (RDB3).


Only found where there are large populations of Tetramorium caespitum.

Flight period

July to early August.

Foraging behaviour

They may occasionally raid neighboring nests of the host species to get more slave pupae.

Nesting biology

This species occurs only in the nests of its host, Tetramorium caespitum. The queen enters a Tetramorium nest and does not kill the host queen. Queens of both species survive in the nest together but production of host sexuals is inhibited. Tetramorium workers continue to be produced and greatly out-number the Strongylognathus workers by around 100:1.

Author of profile

M G Fox

Year profile last updated