The attraction of Lepidoptera to flowering plants also attractive to parasitoids (Diptera, Hymenoptera)

Abstract

Flowering plants added to agricultural environments can provide food, shelter and alternative hosts for natural enemies and so increase crop yields. However, these same resources might be exploited by certain pests. Twelve species of plants known to attract parasitic Hymenoptera and Tachinidae and candidates for conservation biological control were examined for their attractiveness to Lepidoptera, a largely herbivorous order. Interception traps (Malaise traps) were erected along the wooded margin of an agricultural field. Under these traps were placed plants with flowers and controls consisting of plants without flowers and/or no plants. Trapped Lepidoptera were counted, their wing lengths (size) measured and when possible identified to family and species. Five of the 12 plant species in flower attracted greater numbers of Lepidoptera than their control(s), and the attracted moths tended to be relatively large species. Flower depth, but not width, was correlated to attractiveness as was floral area, but not plant height. Finally the relative capacity of plants to attract both natural enemies and selected herbivores was compared. Such comparisons are useful in choosing non-crop plants for inclusion in agro-landscape modifications.