Response of the parasitoids of stored-product moths, Habrobracon hebetor, Trichogramma evanescens and Venturia canescens (Hymenoptera: Braconidae, Trichogrammatidae, Ichneumonidae), towards three types of funnel traps

摘要

The response of the parasitoids of stored-product moths, Habrobracon hebetor, Trichogramma evanescens and Venturia canescens, towards funnel traps was tested under semi-field conditions. Three types of differently coloured traps were tested: dark green traps; traps with a green top, yellow funnel and white cup; and traps with a green top, green funnel and transparent cup. The spectral reflection of the colours of the traps was determined. The traps were baited with the synthetic main component of the female sex pheromone, ZETA. In additional trials conducted with V. canescens, traps were provided exclusively with ZETA (i.e. without water) or exclusively with water (i.e. without ZETA). Most individuals of T. evanescens and V. canescens were caughtwith the yellow/white funnel/cup combination; second best was the green/transparent combination; fewest parasitoids were caught with the green traps. Evaluating the attractiveness of differently baited traps towards V. canescens, traps baited exclusivelywith water and those with water and ZETA caught about the same number of parasitoids, 32 percent. The present study suggested that the colour of the funnel traps is responsible for the attractiveness towards the tested parasitoids. Depending on the colour of the traps, they can be used to trap both moth pests and released or naturally occurring parasitoids. Moreover, funnel traps were identified that attract the moths, but not the beneficials. Monitoring can therefore be integrated with mass releases of parasitoids.