S14 - Session P4 - Monitoring and control method of Contarinia pyrivora in pear organic orchard

Authors: Benjamin Gandubert *, Marion Decultot

Contarinia pyrivora (pear midge) is a very problematic secondary pest in organic pear orchards. It can cause up to 70% of production losses. At the moment, no effective control method compatible with the specifications of organic farming has been found. In addition, the knowledge of that type of pest is limited. Meanwhile, the pest pressure continues to increase in France. The emergence of Contarinia pyrivora can be detected by chromatic trapping. The pest does not seem specific of the varieties, the attacks depend on the phenological stage of the pear trees (D3). Trees near emerging places may also be more susceptible to the attack. To control the pest, the picking and export of infested fruit from the orchard seem effective. Nevertheless, this method is time-consuming. In the field, the quassin positioned on young larvae after hatching has demonstrated a good efficiency. Diatomaceous earth used as a physical barrier to prevent spawning and spinosad applied during adult flight has shown to be ineffective. A slight efficiency is apparent for pyrethrin with the same positioning as for spinosad. In the laboratory, Steinernema feltiae nematodes appear to slightly reduce the number of living Contarinia pyrivora larvae present in the soil.