Behaviour of European Spruce Bark Beetle—Ips typographus (L.) on Poisoned Traps

Abstract

Deployment of poisoned trap trees/logs is an efficient suppressive method to fight Ips typographus (L., 1758) (Coleoptera: Curculionidae: Scolytinae), a calamity pest of spruce stands in the European area during the gradation period. Logs from Picea abies (L.) H. Karst., 1881 (Pinales: Pinaceae) laid as traps were baited with IT Ecolure pheromone and were treated with Forester insecticide containing cypermethrin as the active substance. Catching frames were placed under the pheromone trap to gather dead imagines. Behaviour of imagines was observed directly in the field and recorded by camera; video records were evaluated in the laboratory. Higher mean air temperature affected favourably the flight activity of Ips typographus and increased the frequency of arrival on and departure from the surface of poisoned trap trees; the imagines stayed on the trap trees for a shorter time. The numbers of dead imagines under the trap trees did not depend on the temperature. The increasing number of live imagines on poisoned trap trees/logs correlated with the increasing proportion of caught dead imagines, decreasing length of live imagines staying on the trap tree, and increasing frequency of arrival to and departure from the trap tree. The presence of pheromone lure and insecticide treatment induced rectilinear and uninterrupted flight towards and away from the pheromone lure. No attempt was observed to gnaw an entrance hole. Mortality on the poisoned trap tree ranged from 18% to 21%; 40%-60% of poisoned imagines died later due to the contamination.