Key to the members of the Lasius alienus group of Europe and Asia Minor

The Lasius alienus group within the European species of the subgenus Lasius s.str. is characterized by no or very few setae on dorsal plane of the scape (differing from the Lasius niger and Lasius emarginatus species groups) and by the masticatory margin of mandibles showing ≥ 8 teeth (differing from the Lasius brunneus group). The data in the key refer to nest sample means.

1a Sparsely haired: nSt 0–1.3, nOcc <8.0, nGu 0–2.5, nHT 0–1. Propodeal dome in medium-sized specimens more conic. Scape shorter: SL/CL 0.921 ±0.019. Body concolorous dark brown.............................................. alienus

1b Less sparsely haired: nSt 1.8–8.0, nOcc 5.2–18.0, nGu 0.9–4.8, nHT 0–8. Propodeal dome in medium-sized specimens more hemispheric.......................................................................................... 2 2a Pubescence on head and mesosoma more dilute, nest means of sqPDCL> 3.82. Terminal (6th) segment of maxillary palps