The influence of prior experience on preference and performance of a cryptoparasitoid Scleroderma guani (Hymenoptera: Bethylidae) on beetle hosts
1. Numerous studies have reported the effects of learning or experience on parasitoid host preference and location. However, the integration of pre-imaginal and adult experiences on the subsequent host preference and adult/offspring performance has been rarely tested in host–parasite interactions. 2. We present direct evidence that theses two kinds of experiences affect host preference and related fitness in the polyphagous parasitoid, Scleroderma guani. Two colonies of parasitoids were reared on Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Individuals from the two colonies were given host-switching experience for one generation (pre-imaginal experience) while other individuals were given prior ovipositing experience on the two species, respectively (adult experience). 3. Scleroderma guani females demonstrated that their experiences determined adult behavioural responses and their subsequent performance to hosts. Females maximized both adult fitness (fecundity and longevity) and offspring fitness (survival and sex ratio) when they encountered hosts similar to their maternal hosts. Behavioural plasticity in host choice was affected by adult experience, resulting in improved adult feeding and ovipositing behaviour and further modifying adult fecundity and the offspring sex ratio. There was a positive correlation between oviposition preference and adult fecundity. 4. The results indicated that S. guani,/i> exhibited positive preference–performance correlations. This is most likely due to an adaptation to maternal hosts over multiple generations. However, foraging potential of adults to available cues from hosts may be driven quickly by an experience-induced learning process rather than by natural selection processes shaped over many generations.