In Europe, the oilseed rape crop is highly dependent on insecticides. The first approach to reduce pesticide usage is to facilitate the identification of pests to avoid unnecessary treatments. However, it is very difficult to identify weevil larvae. Another approach is to develop new crop protection strategies, for example by enhancing natural control in agro-ecosystems. Today, references and knowledge about the natural enemies associated with the pests of oilseed are poor. In France, the last inventory of the parasitoids of oilseed rape pests date back to the 60’s !

In this context, the main objectives of the project are 1) to inventory the parasitoids of key weevil pests of oilseed rape; 2) to provide a validated molecular tool to identify weevils at any stages, as well as their parasitoids. We will make available an online database with all the infos and sequence data gathered during the project. Ultimately our goal is to identify and hopefully quantify insects associated with rape crop (pests and natural enemies) in several areas (with or without pesticide use). This should facilitate new research to identify the impact of agricultural practices or landscape management on the pests and their natural enemies. This project is conducted in collaboration with Terres Inovia the technical center for oilseed crops, grain legumes and industrial hemp.

During the course of the project we tested a promising and easy to implement high throughput approach to sequence the barcode fragment (COI) for all the species (weevils and their natural enemies). We are now in the final stage of the project and the database will be soon available thanks in particular to Mélodie Ollivier's work during her MSc. We are now testing our high throughput approach for a real-size test to identify larva to species and test the impact of pesticide use on parasitism rate. So more to come soon ...

Leader : C. Robert (Terres Inovia).

People Involved : A. Cruaud, J.-Y Rasplus, J.-C Streito, G. Genson, E. Pierre. Collaboration with G. Delvare (CIRAD)

Project founded by the French Ministery of Agriculture