Megalomyrmex wettereri Brandão

Megalomyrmex wettereri Brandão, 2003: 155, figs 1–4. Holotype worker: La Selva, 10°26'N 84°01'W, 50–150 m, Heredia Prov., Costa Rica, 2 Mar 1993 (Wetterer) [MCZ] (paratypes examined). Paratype queen: km 7 of El Llano Carti Suitupo Road, Panama, 7 Jun 1998 (U. Mueller 980607–01) [MZSP] (not examined).

Megalomyrmex sp. nov.: Adams et al. 2000: 549 –554.

Measurements. Worker: HW 0.523, HL 0.588, SL 0.497, EL 0.076, ML 0.817, CI 89, SI 85 (n=1, present study, from same nest series as holotype).

Geographic range. Costa Rica, Panama.

Biology. Megalomyrmex wettereri is known from two lowland rainforest sites: Barro Colorado Island in Panama and La Selva Biological Station in Costa Rica. Observations from Barro Colorado were the subject of Adams et al. (2000). Colonies of M. wettereri were found occupying abandoned nests of Cyphomyrmex longiscapus Weber. The fungus gardens of the Cyphomyrmex Mayr were intact and the Megalomyrmex workers were observed feeding on the fungal symbiont. When lab colonies of M. wettereri were placed in contact with colonies of C. longiscapus, the M. wettereri aggressively attacked, killing the adult workers. When presented with Cyphomyrmex larvae, they stripped them of their fungal coating and fed them to their own larvae. Adams et al. concluded that M. wettereri was an "agro-predator," raiding Cyphomyrmex colonies en masse, displacing the Cyphomyrmex workers, and feeding on the remaining brood and fungi.

The holotype series was a colony collected by Jim Wetterer at La Selva. He found the colony inhabiting a nest of Trachymyrmex cornetzi (Forel) (Brandão 2003 identified the attine as T. bugnioni (Forel); I identify this common La Selva attine as T. cornetzi).