Nesomyrmex innocens (Forel, 1913)

Figs 12B, 13A, 19

Tetramorium (Leptothorax) innocens Forel, 1913: 317 (w.), D.R. Congo.

Leptothorax innocens – Forel 1916: 425.

Nesomyrmex innocens – Bolton 2003: 272 (see also Bolton 1982: 330).

Diagnosis

The following character combination distinguishes N. innocens from the other members of the group: eyes with 7–9 ommatidia in longest row; in profile mesosomal dorsum with conspicuously impressed metanotal groove; propodeal spines short and thick, elongate-triangular and only weakly longer than their basal width; in profile petiolar node nodiform, appearing approximately as long as high; in dorsal view petiolar node laterally denticulate; subpetiolar process without a long cuticular flange running back to the postpetiolar junction; dorsum of propodeum with standing hairs; first gastral tergite with standing hairs evenly distributed throughout.

Diagnostic comments

As noted in the description of N.denticulatus, the latter, N.innocens and N. stramineus are morphologically relatively close. Nesomyrmex innocens and N. stramineus differ from N. denticulatus by generally smaller body size, smaller eyes with less ommatidia, and a subpetiolar process without a long cuticular flange running back to the postpetiolar junction. The separation of N. innocens and N. stramineus is a bit more difficult, as already mentioned by Bolton (1982). Nesomyrmex innocens has shorter and thicker propodeal spines and a lower and thicker petiolar node compared to N. stramineus . It is not clear at the moment whether or not these character states are sufficient to maintain their heterospecificity in the long term. Bolton (1982) had some doubts about this, too, and it is possible that they represent geographical varieties of the same species. However, at present, based on the scarcity of the material, especially of N. innocens, we treat them as two different species.

Biology

Based on the limited data available, N. innocens nests in the stem of trees.

Distribution and biology

This species is only known from very few specimens, collected from the D.R. Congo and Kenya.