Niche partitioning among diverse Pseudacteon parasitoids of fire ants

Sunday, November 10, 2013: 2:05 PM
Meeting Room 8 C (Austin Convention Center)
PJ. Folgarait , Laboratorio de hormigas, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina
Any sound biological control program should be based on solid basic information. The Pseudacteon –Solenopsis system has been intensively studied during the last 15 years in order to gather essential information for evaluating the use of these exotic parasitoids to control fire ants in the US.  Fire ant´s Pseudacteon communities vary in their richness but could have up to 13 species in their native habitats. The assembly rules involved in their coexistence are driven by characteristics that allow niche partitioning, given their potential overlap according to their geographical range distribution.  The main dimensions of their niche that allow exploiting the same resource are related to as how fire ant parasitoids use their host since the mentioned flies constitute a guild. Different Pseudacteon species use a particular host size range, locate the host at specific microhabitats, have different circardian and circanual rhythms, have different oviposition strategies and competitive abilities, and most probably particular physiological capacities to withstand differing weather conditions. Besides, different Pseudacteon species have particular sex ratios depending on  if there is sexual size dimorphism based on host sizes and also they have different developmental periods; both characteristics that help coexistence of multiple species.  All these traits plus their level of aggression and success of oviposition, and easiness of rearing, allow selection of a complementary group of species to introduce in the US as potential biological control agents of fire ants.