Nuptial Flight in two Ponerine Ants,Pachycondyla Impressa and P. Fauveli,Overlooking Machu Picchu,Peru

We report on a simultaneous nuptial flight of ants of two sympatric ponerine species, Pachycondyla impressa and P. fauveli, on the top of Huayna Picchu (2700 m), Peru. After flying in and landing on the flat, hare rocks of the summit, the conspecific sexuals approached, antennated and mated without any previous female calling behaviour. During one hour of observation, the number of approximately 30 ♂ ♂ and ♀ ♀ Pachycondyla impressa and 70–86 of P. fauveli on the site remained constant because of individuals continuously arriving and leaving. Although nuptial flight seems to be the most common type of mating system in ants, this is one of the very few reports on the occurrence of this behaviour in ponerine species.