Formica irritabilis

Smith, F., 1858, Catalogue of the hymenopterous insects in the collection of the British Museum. Part VI. Formicidae., London: British Museum : 25

85. FORMICA IRRITABILIS . B.M.

Worker. Length 4 lines,-Head, thorax, and scale of the abdomen, ferruginous, the legs rufo-fuscous; abdomen nearly black; the scape black, with the extreme base and apex as well as the flagellum ferruginous, the latter more or less fuscous above; the vertex has sometimes a fuscous stain; the mandibles nigro-piceous, their apex ferruginous. Thorax compressed behind, much narrower than the head, both thinly sprinkled with erect reddish hairs; the legs nigro-fuscous, with the base and apex of the joints, and sometimes with the coxae and apical joints of the tarsi, ferruginous. Abdomen: the scale oblong-ovate, pointed above; the apical margins of the segments with a thin fringe of reddish-yellow hairs.

Hab. Borneo (Sarawak).