Simopone emeryi

Bolton, Barry & Fisher, Brian L., 2012, Taxonomy of the cerapachyine ant genera Simopone Forel, Vicinopone gen. n. and Tanipone gen. n. (Hymenoptera: Formicidae) 3283, Zootaxa 3283 (1), pp. 1-101 : 13-14

Characters of emeryi species group (workers)

1 Palp formula 6,4 ( conradti , dux , grandis , latiscapa , marleyi , nonnihil , persculpta , rex , sicaria , silens , trita ).

2 Mandibles sculptured, even if only feebly so.

3 With head in profile the parafrontal ridge fails to reach the anterior margin of the eye (i.e. it is confined to the area immediately behind the clypeus), or may be absent.

4 Mesopleuron without an impressed transverse sulcus that divides it into anepisternum and katepisternum.

5 Propodeal spiracle is roughly circular to distinctly elliptical.

6 Pygidium with a distinct cuticular apical fork of two short, stout teeth.

7 Generally relatively large species, worker HW 0.74–2.18.

It is interesting to speculate on the function of the pygidial fork. Its function could be to brace the apex of the abdomen against the cuticle of a victim immediately prior to stinging, and thus prevent the apex from sliding over the surface. Or it may act as a guide and brace for the sting when it is in use. From its position immediately above the sting it may serve to prevent lateral movement or slippage of the sting during insertion.