Monitoring of click beetles (Agriotes lineatus and A. obscurus) in organically managed farms in Northern Germany

Kurzfassung

Wireworms, the larvae of Agriotes spp., are an increasing problem on many organically managed farms with potato or vegetable production. The damage caused by wireworms is economically significant. With the use of pheromone traps it is possible to get more information about the habitat requirements of click beetles. In 2005 and 2006 click beetles were monitored at different locations in northern Germany. Because of the warmer springtime in 2005, the first peak of click beetles was about two weeks earlier than in 2006. The second peak was found one month later. The presented data show the highest occurrence of click beetles in ryegrass-clover mixtures in both years. The catches in cereals were much lower than in ryegrass-clover. The reasons for the differences of the trapped click beetles in the different cereal fields cannot been explained so far. In the majority of cases the trapped number of Agriotes lineatus was higher than for A. obscurus.