Pheromones and other semiochemicals of click beetles - a European perspective

The implementation of IPM strategies against wireworms, the larvae of click beetles (Coleoptera, Elateridae) has been very difficult because of the time- and energy-consuming detection and monitoring methods. It was hoped that - similarly to Lepidoptera - if pheromones of click beetles became known, they could assist in the development of simple and easy-to-use tools and methods for this purpose. I give an overview of my lab’s contribution to the research on click beetle semiochemicals in Europe in recent years.

Through identification of pheromones for new species, and by improving published pheromone compositions for others we managed to develop powerful pheromone lures for Agriotes brevis, A. lineatus, A. litigiosus, A. obscurus, A. proximus, A. rufipalpis, A. sordidus, A. sputator and A. ustulatus, (the species with greatest economic importance in Central, Southern and Western Europe). These lures applied in the „YATLOR funnel“ (YF) traps specifically developed for the capture of click beetles, are in wide use in European agriculture for the study of geographic occurrence and abundance, for detection and flight monitoring, etc. Widespread studies on establishing correlations of trap captures of adults with larval densities are also underway.

We have increasing evidence that female click beetles are also responding (although to a lesser extent than the males) to their own pheromones, which fact brought up the possibility of the development of trapping tools capable of capturing both sexes of click beetles. The first such example is presented for A. ustulatus, where a combined application of the synthetic pheromone and a synthetic floral lure (developed earlier) catches high numbers of both females and males. This phenomenon also supports the hypothesis that click beetle pheromones in the Agriotes genus are not „classical“ sex pheromones, rather they show characterstics of aggregation pheromones.

Acknowledgements

Research presented was partially supported by OTKA grant K81494 of HAS.