Early life nutritional quality effects on adult memory retention in a parasitic wasp

International audienceNutritional quality during early life can affect learning ability and memory retention of animals. Here we studied the effect of resourcequality gained during larval development on the learning ability and memory retention of 2 sympatric strains of similar genetic backgroundof the parasitoid Trichogramma brassicae: one uninfected and one infected by Wolbachia. Wolbachia is a common arthropodparasite/mutualistic symbiont with a range of known effects on host fitness. Here we studied, for the first time, the interaction betweenresource quality and Wolbachia infection on memory retention and resource acquisition. Memory retention of uninfected wasps wassignificantly longer when reared on high quality hosts when compared to low quality hosts. Furthermore, uninfected wasps emergingfrom high quality hosts showed higher values of protein and triglyceride than those emerging from low quality hosts. In contrast, thememory retention for infected wasps was the same irrespective of host quality, although retention was significantly lower than uninfectedwasps. No significant effect of host quality on capital resource amount of infected wasps was observed, and infected waspsdisplayed a lower amount of protein and triglyceride than uninfected wasps when reared on high quality hosts. This study suggeststhat the nutritional quality of the embryonic period can affect memory retention of adult wasps not infected by Wolbachia. However, bymanipulating the host’s obtained capital resource amount, Wolbachia could enable exploitation of the maximum available resourcesfrom a range of hosts to acquire suitable performance in complex environments