Key to Metapone of Africa and Madagascar

This worker key is based on: Taylor, R. W. and G. D. Alpert, G. D. 2016. The myrmicine ant genus Metapone Forel (Hymenoptera: Formicidae): a global taxonomic review with descriptions of twelve new species. Zootaxa. 4105(6):501-545.

The three known Madagascan species were reviewed by Alpert (2007), with notes on their association with termites—a subject discussed further by Hölldobler and colleagues (2002, 2002). Metapone africana from equatorial Gabon is the only known continental African Metapone species. In physiognomy, colour, sculpturation and details of the relatively unelaborated clypeal and subpetiolar structure these are apparently generalized taxa, similar to others in the Asian and Australian faunas (e.g. Metapone javana, Metapone krombeini, Metapone mathinnae, Metapone truki), and possibly somewhat archetypical in Metapone. Metapone emersoni appears slightly the more morphologically derived of the four.

1

Lateral margins of raised median portion of clypeus markedly convergent anteriorly from the level of the antennal insertions. Petiolar dorsum from above approximately twice as wide as long. Postpetiolar sternite in profile view appearing as a long, slender process (Madagascar) . . . . . Metapone emersoni

Lateral margins of raised median portion of clypeus essentially parallel, at most only slightly convergent anteriorly. Petiolar dorsum from above quadrate to transverse, maximally only about 1.4x wider than long. Postpetiolar sternite in side view extended as a much shorter process; digitate or acute in lateral view, obtusely triangular in frontal view . . . . . 2

2

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Median clypeal surface transversely flat to slightly convex; lateral borders not raised; anterior border entire, without median denticles, very slightly concave in frontal view, with a small step-like marginal excision on each side. Smaller species, HW > 0.76mm. (Angola) . . . . . Metapone africana

Median clypeal surface transversely concave, the lateral borders slightly raised, subcarinate; anterior border medially bidentate, lacking anterolateral marginal excisions. Larger species, HW < 0.90mm. (Madagascar) . . . . . 3

3

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Petiolar node from above approximately as wide as long; postpetiolar sternum in side view bluntly rounded . . . . . Metapone vincimus

Petiole from above approximately 1.4 times as wide as long; postpetiolar sternum in side view forming a low acute point . . . . . Metapone madagascarica