Ground-living predators of the apple fruit moth Argyresthia conjugella (Zell.)

Sammanfattning: Field studies were conducted in two orchards to investigate what type of ground- living predators that prey on the apple fruit moth during hibernation. Two tasks were addressed: 1) hibernation loss of the apple fruit moth was quantified, and 2) effect of the different predator groups were identified. This was done in a spring experiment and an autumn to spring experiment with mesh exclusion cages. The results were analyzed with the GLIMMIX procedure in SAS. The field studies were complemented with feeding tests in laboratory with spiders, ants, staphylinids and carabids that were supposed to detect and eat apple fruit moth pupae. In spring and autumn, large insects between 5 to 11 mm, were the major predator of the apple fruit moth, while the smaller insects of sizes 0-5 mm, dominated the predation during winter. Small rodents (11-20 mm) had little or no predation effect on the apple fruit moth pupae, probably because the pupae were too small to be detected as a food source. Both ground-beetles (Pterostichus sp. and Harpalus latus) and staphylinids were able to detect and eat apple fruit moth pupae in the feeding test. Spiders and ants did not eat apple fruit moth pupae in the feeding test.