Hypoponera dulcis

dulcis group

Species with the following combination of characters in the worker caste.

1 Metanotal groove present and strongly developed across dorsum of mesosoma; always a strongly defined deep groove that conspicuously interrupts the surface.

2 Mesonotal-mesopleural suture present.

3 Petiole node squamiform.

4 Eyes present, small but always distinct.

5 Maximum width of first gastral tergite in dorsal view is equal to or slightly less than the width of the second tergite at its midlength.

6 Cinctus of second gastral tergite smooth, without cross-ribs at its base.

7 Anterior clypeal margin lacks a median indentation or notch.

Only a single species of this group, dulcis, occurs in sub-Saharan Africa, where it is extremely common and very widespread; in fact it is the most common and most abundant Afrotropical Hypoponera species. A scan of the rest of the world’s fauna indicates that there are abundant species in the Oriental, Malesian, Austral and Neotropical regions that apparently belong in the same group as dulcis. Given the abundance of this group elsewhere and the presence of only a single species in the Afrotropical region, the possibility that dulcis may represent an ancient but very successful invasion from outside the region must be considered.