Lasius

Genus Lasius Fabricius, 1804 Lasius Fabricius, 1804:415. Type-species: Formica nigra Linne, 1758. The antennae are 12 segmented in the worker and female, 13 segmented in the male. The antennal insertions are situated at the posterior margin of the clypeus and segments2 to 5 are not longer than the s...

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Bibliographic Details
Main Author: Collingwood, C. A.
Format: Other/Unknown Material
Language:unknown
Published: 1979
Subjects:
Online Access:https://zenodo.org/record/6283842
https://doi.org/10.5281/zenodo.6283842
Description
Summary:Genus Lasius Fabricius, 1804 Lasius Fabricius, 1804:415. Type-species: Formica nigra Linne, 1758. The antennae are 12 segmented in the worker and female, 13 segmented in the male. The antennal insertions are situated at the posterior margin of the clypeus and segments2 to 5 are not longer than the succeeding segments. Maxillary palps are 6 segmented, labial palps 4 segmented. The head of the worker caste is somewhat cordate with a posterior emargination in some species. The clypeus is broad and rounded anteriorly. The frontal carinae are short and sub-parallel and in most species the frontal triangle is indistinctly defined. The orifice of the propodeal spiracle is circular or broadly oval situated close to the posterior propodeal border. Ocelli are minute or indistinct in the worker but distinct in the female and male. The petiole is vertical and scale-like in most species. This genus contains about 42 species with a holarctic distribution. It was extensively revised by Wilson (1955). Members of this genus are predominantly aphidicolous but also carnivorous and scavenging. There are 14 species in Europe of which IO are known to occur in Fennoscandia. Keys to species of Lasius Workers 1 Colour shining black; head large, broadly cordate with a distinct posterior emargination (Fig. 137). 37. fuliginosus (Latreille) Colour greyish or brownish black or yellow. 2 2(1) Colour yellow to brownish yellow; maximum eye length 1/4, head width or less. 3 Colour brownish or greyish black or somewhat bicoloured reddish and black; maximum eye length more than head width. 8 3 (2) Petiole nodal with dorsal crest in front view strongly convex; head emarginatc posteriorly; with genal margins rounding in towards close set mandibular insertions(Figs. 153,155). 42. carniolicus (Mayr) Petiole with thin dorsal crest, straight or emarginate in front view; back of head convex and genal margins not pronouncedly sloping in towards mandibular insertions which are wide set. 4 4 (3) Front tibiae and antennal scapes with sub-erect hairs ...