Abstract

Mechanical control involving nets and screens to physically exclude insect pests from pome fruit is an effective and sustainable method to suppress insect damage reducing the insecticide usage. The successful of these netting systems can be affected by several factors, including the tree crop architecture. Studies were conducted in 2022-2023 to evaluate the effectiveness of single-row exclusion netting in the management of codling moth, Cydia pomonella L., in pome fruit orchards. White netting (6.0 mm x 1.8 mm mesh) was placed in plots of apple and pear of different canopy structures (central leader, spindle, and V-trellis). Releases of sterilized male and female moths were conducted inside and outside netting. Delta traps baited with a sex pheromone or kairomonebased lure were used to monitor C. pomonella flight inside and outside replicated plots. Wild and sterile females caught in traps were dissected to determine their mating status. The exclusion netting significantly reduced the occurrence of fruit injury from C. pomonella and birds compared to unnetted adjoining trees. The recapture of sterile moths was very low in the netted spindle trees, while a moderate number of moths were recaptured under the other two training systems. Similarly, the proportion of mated sterile moths was higher in the V-trellis plots compared with the spindle trellis. The catch and level of mating of wild moths in these plots were also highest with the V-trellis. Fruit injury recorded in both the V-trellis and central leader canopies were primarily from the first generation and only small clusters of injury occurred in the second half of the season. These data demonstrate the relative effectiveness of exclusion netting for C. pomonella management can be influenced by the canopy structure and the degree of open space remaining under the netting for successful moth flight and sexual communication.