Levels of parasitism of Xenos myrapetrus (Stresiptera, Stylopidae) and its seasonal changes in the swarm-founding wasp, Polybia paulista (Hymenoptera, Vespidae)

Abstract

ABSTRACTSocial insects face strong selection from parasites because the conditions of group living often favor the transmission of infection among nestmates. Yet, we lacked detailed information on the effect of parasite infection in the host species. Workers of Polybia species, Neotropical swarm-founding wasps, are commonly infected by strepsipteron, possibly Xenos myrapetrus (Trois). Previous studies showed in two Polybia species that workers infected by the strepsiptera were smaller than uninfected workers. However, the effect of seasonality on infection rates throughout a year or between wet and dry seasons has not been examined. We compared rates of strepsiptera infection in workers of Polybia paulista between wet and dry seasons or among months. Infection rates by the strepsiptera in workers are generally low throughout a year, but different between the seasons. However, there is no particular tendency on seasonal differences of workers infected by the strepsiptera. Population dynamics of the parasites and temperature variation can have effects on the differences.