Life history traits and foraging behaviour of Cotesia nonagriae (Ollif) (Hymenoptera: Braconidae), a newly recognised member of the Cotesia flavipes complex of stemborer parasitoids

Cotesia nonagriae (Olliff) from Australia, a parasitoid of the incidental native pest of sugarcane, Bathytricha truncata (Walker) (Lepidoptera: Noctuidae), was previously thought to be a synonym of Cotesia flavipes Cameron. However, recent studies using DNA sequences, morphology and preliminary biological information show that this parasitoid is clearly a different species than C. flavipes and other members of the species complex. Here we further examine differences in the biology of these species by undertaking a detailed study of the life history traits of C. nonagriae, including adult longevity and the potential and realised fecundity of females. In addition, the influence of learning on microhabitat location and foraging behaviour were investigated. Duration of the larval stages and adult longevity of C. nonagriae were longer than previously recorded for other members of the species complex. The potential fecundity of females was similar to C. flavipes (∼200 eggs); however, C. nonagriae oviposited a average of over 100 eggs into each host, almost three times more than for other species in the C. flavipes complex (30-40). The propensity of C. nonagriae to allocate a large number of eggs to each host may be an evolutionary strategy due to the high mortality rate (50-57%) of ovipositing adult wasps. During microhabitat location, both naïve and experienced females demonstrated a strong response towards the plant host complex, with experienced wasps benefiting by having a more rapid response time to host-induced volatiles and cues. © 2010 The Authors. Journal compilation © 2010 Australian Entomological Society.Kate A. Muirhead, Nader Sallam and Andrew D. Austi