Asobara, braconid parasitoids of Drosophila larvae: unusual strategies to avoid encapsulation without VLPs

Abstract

Ichneumonoidae parasitoids have been well described for their regulatory effects on host physiology which are usually associated with the activity of polydnaviruses (PDVs) or viruslike-particles (VLPs) injected by the female wasps at oviposition. Among them, parasitoids of the braconid families display specific characteristics like the required activity of secretions from the maternal venom glands or of teratocytes from embryological origin. However, none of these features were observed in two braconid species of the Asobara genus parasitizing Drosophila hosts. In the absence of PDVs and VLPs, the two species A. tabida and A. citri seem to have developed unique strategies to avoid immunity defenses and to succeed in their Drosophila larval hosts. The aim of this study is to report on the complex relationships of braconid parasitoids with their hosts and to present some of the insights from studying Drosophila parasitoids.