Camponotus

Genus Camponotus Mayr, 1861

Camponotus Mayr, 1861:35.

Type-species: Formica ligniperda Latreille, 1802.

This is a world wide genus with a large number of species reaching their greatest abundance in the tropics. The form of the alitrunk and head varies considerably. Although attempts have been made to differentiate species groups, it has not been possible to make clearcut distinctions in all cases to justify the use of subgeneric names. Despite the variety of form, the attachment of the antennal scape some distance from the clypeal border is a constant feature that immediately distinguishes the genus from Formica and Lasius. The antennae are 12 segmented in the female and worker, 13 in the male; segments 2 to 5 are marginally longer than those following. Maxillary palps 6 segmented, labial palps 4 segmented. Frontal carinae are sinuate broadening behind the antennal insertions. Ocelli are absent in the worker, small but distinct in the female and male. Wings with one discoidal cell, cubital cell absent. Male external genitalia small.

In North Europe the 4 Fennoscandian species all mine in dead wood but only C. herculeanus occasionally mines in live trees. This and C. ligniperda are among the largest ants found in Europe with major workers up to 12 or 14 mm long and females up to 18 mm long.

Keys to species of Camponotus

Workers

1 Front clypeal border incised in middle (Fig. 114)............... 29. fallax (Nylander)

Front clypeal border entire............................................................................ 2

2 (1) Colour uniformly black; pubescence thick; projecting hairs profuse over whole body including gaster (Fig. 118)........................................... 30. vagus (Scopoli)

Colour in part reddish; pubescence thin; hairs on gaster sparse mainly restricted to tergite borders............................................................................ 3

3 (2) Gaster shining with pubescence short, sparse often absent over medial areas of first and second gaster tergite. Basal face of first tergite and sometimes whole tergite reddish; alitrunk bright yellowish red to dark red 32. ligniperda (Latreille)

Gaster somewhat dull with long pubescence evenly distributed over dorsal surface; basis of first gaster tergite often with a small reddish patch behind scale; alitrunk dull red, sometimes reddish black............ 31. herculeanus (Linne)

Queens

1 Front clypeal border incised in middle; size smaller: head width 2.0-2.2mm 29. fallax (Nylander)

Front clypeal border entire; size larger head width over 3 mm.........................

2 (1) Colour uniformly black with thick pubescence and numerous standing hairs on gaster................................................................................ 30. vagus (Scopoli)

Bicoloured with at least propodeum reddish................................................... 3

3 (2) General appearance shining, pubescence short sparse or absent over medial area of first gaster tergite (Fig. 122). Punctuation on frons shallow 32. ligniperda (Latreille)

General appearance somewhat dull, gaster pubescence long and evenly distributed over surface (Fig. 123). Punctuation on frons deep 31. herculeanus (Linne)

Males

Front border of clypeus with shallow emargination........... 29. fallax (Nylander)

Front border of clypeus convex...................................................................... 2

2 (1) Long hairs abundant over dorsum of head and gaster; dorsal crest of petiole sharply angled at sides enclosing wide and deep emargination (Fig. 115) 30. vagus (Scopoli)

Head and dorsal surface of gaster with sparse hairs; petiole with shallow emargination and sides of dorsal crest more rounded (Fig. 121)................................ 3

3 (2) From above, gaster fringed at the sides with scattered projecting hairs; pubescence long (0.075-0.125 mm)..................................31. herculeanus (Linne)

From above, first two gaster tergites usually without hairs; pubescence sparse and short (0.05 mm)..................................................... 32. ligniperda (Latreille)