As part of investigating nestmate discrimination, I decided to test if Comanche can distinguish other ant species. So I ran behavioral trials between the Comanche harvester ant (Pogonomyrmex comanche) and the Barbatus harvester ant (or harvester ants or big red ants, Pogonomyrmex barbatus) and: !
Comanche are pansies — mostly they did nothing, either in arenas with P. barbatus or when P. barbatus was introduced to their nest mound near the entrance. In fact, P. barbatus sometimes entered the nest seemingly without harm since they also returned to the external nest.
Out of 19 arena encounters, there were 4 with any aggression and only one of these had an extended grabbing encounter. Barbatus was always the aggressor.
Out of 14 on the nest encounters, 2 showed some aggression by Comanche, mostly a kind of harassment. Mostly, Barbatus just left the mound though twice barbatus entered the nest. Once Barbatus showed great difficulty maneuvering over the sandy mound.
All trials were recorded with a camcorder so I am still analyzing them.