Hail nets enhance disruption of sexual communication by synthetic pheromone in codling moth

We hypothesized that polyethylene anti-hail nets interact with synthetic pheromone in disrupting the sexual communication of codling moth Cydia pomonella L. We tested this hypothesis through the release and recapture of m ales in field cages. This set-up allowed normalisation of the male population during the treatments. The effect of the net was also estimated through recording additional parameters such as wind speed, temperature within the canopy, and pheromone emissions from mating disruption dispensers. The experiments were carried out in orchards with or without hail nets, and with or without pheromone disruption treatment. In the release and recapture assay the hail net significantly decreased the success of sexual communication in association with the mating disruption treatment. In plots without synthetic pheromone, the net did not affect communication between the sexes. Both wind speed and canopy temperatures were mitigated by the presence of the net. Pheromone emissions from disruption dispensers did not differ for covered and uncovered plots. The increase in communication disruption with the hail net is of practical interest and opens up possibilities for extending the use of mating disruption to orchards where climatic or topographic features currently limit the efficacy of this sustainable method