Predation of Codling Moth Eggs, Cydia pomonella, the Predators Responsible and Their Alternative Prey

Abstract

12-86%4 of codling moth eggs glued to the leaves and fruit of a cider-apple orchard at weekly intervals throughout the summer were sucked out, and 3-29%4 disappeared. The mortality of the natural population of eggs is estimated to be lower than this, because in laboratory tests all predators were less likely to feed on naturally-laid eggs than on glued ones. The numbers and biomass of six species of Heteroptera and one mite able to suck out the contents of codling moth eggs, and the numbers of earwigs, which are thought to be responsible for egg disappearance, were recorded in the foliage. Because of their low numbers, codling eggs are not thought to be an important food source for these predators. The major prey of heteropteran predators is probably the fruit tree red spider mite, Panonychus ulmi, because their numbers and weights fluctuated in relation to the abundance of this prey, and no other. It is concluded that the heteropteran predators of P. ulmi also usefully reduce the abundance of codling moth eggs and subsequent damage to the fruit.