Do floral resources affect fitness of adult Cydia pomonella (Linnaeus 1758) (Lepidoptera: Tortricidae)?

Abstract

The introduction of flowering plants into orchards can increase functional biodiversity in pome fruit cultivation. Plants provide nectar, pollen and prey resources supporting pollinators and natural enemies. However, pests may also benefit from floral diets and a careful selection of plants is necessary to reduce any risk of pest proliferation. The codling moth Cydia pomonella is a major pest in apple growing worldwide and adults are known to consume sugars. The impact of floral diets (parsnip, wild carrot, coriander, red clover) on longevity, fecundity and fertility of adult codling moth was examined under laboratory conditions. In general, male moths lived longer than females, regardless of dietary treatments. Moths survived longest when supplied with parsnip flowers as a floral diet. Contrary to carrot, coriander resulted in higher longevity of adult C. pomonella compared to moths provided with red clover as a negative control. Adult nutrition on floral diets did not affect fecundity substantially. As expected, the majority of eggs were laid within the first week. Prolongation of moths' lifespan by floral diets did not significantly increase the total number of eggs laid in contrast to a diet with 25% sucrose solution. According to these results, the risk of inadvertently promoting codling moth when growing selected flowering plants in the orchard will be rather low, because the fitness of the moths and especially the reproduction of the females will not be substantially enhanced.