aphidophaga 13

Introduction: Chemoreception is the main mechanism used by insects to communicate both intra-species and inter-species, and to interact with their environment. The specialized organs for this function are sensilla, mainly located on the antennae, but also on tarsis, palpi and genitalia. At the molecular level, it is essential the role of OBPs that solubilize and carry the odorant molecules towards the specific receptors. In the aphid parasitoid Aphidius ervi (Hymenoptera: Braconidae), host acceptance is based on the perception of specific kairomones present on the aphid cuticula and cornicle secretions. Methods: Antennal sensilla of A. ervi were investigated using both SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy). The proteic profile of Aphidiuservi has been determined by working on the construction and annotation of de novo transcriptome, using the specific bioinformatic tool Blast2Go. Results: At least two type of putative olfactory sensilla were found, one of the “placoidea” and the other of the “grooved peg” type. The first type is the most abundant and was found on most of the antennomeres evenly distributed on the whole surface. The groveed peg occurs only on the distal part of some antennomeres. The analysis of the transcriptome allowed us to identify the transcripts which mediate olfactory perception, in particular several OBPs and other molecules that were identified and characterized. Conclusions: The study of the molecular basis of olfaction, by the identification of OBPs, provides useful information to better understand OBPs functioning and their interaction with odorant molecules. Then, it will be possible to test different compounds in order to determine their effects on A.ervi behaviour, and their applicability in aphids’ biological control.