The alpha-cypermethrin coated net for protecting Norway spruce wood against bark beetles (Curculionidae, Scolytinae)

Abstract

Abstract The study estimated the efficacy of a net coated with alpha-cypermethrin used to protect Norway spruce [Picea abies (L.) H. Karst] wood against bark beetle infestations. The inside of the net was coated with 100 mg/m2 of alpha-cypermethrin. The studies carried out in 2010 and 2011 took place in southern Poland in the Beskid Żywiecki and Beskid Sądecki mountains in P. abies stands threatened by Ips typographus (Linnaeus, 1758). The research material consisted of wood logs taken off of 70–80-year-old P. abies trees. The logs were wrapped in the net in the early spring before spring swarming of bark beetles. The unwrapped logs were considered as the study controls. An evaluation of the treatments was performed after 2 months. The evaluation was based on the counting of bark beetles galleries found after removing the bark from the wrapped and unwrapped logs. There were no insect galleries on the wrapped logs. The net was a barrier, on which bark beetles died. About 10 dead I. typographus beetles were found on 0.01 m2 of the net surface. On the bark from the unwrapped-control logs there were 3,156 galleries/entrance holes of bark beetles, in total, of which 73% belonged to I. typographus, 13% to Pityogenes chalcographus (Linnaeus, 1761), and almost 10% to Xyloterus lineatus (Oliv.). These results indicated the high efficacy of the net coated with alpha-cypermethrin used for the protection of Norway spruce wood against the bark beetles. At the same time, the net was found to have a negative effect on non-target entomofauna, mainly Hylobius spp., Thanasimus formicarius (L.), and Tetropium castaneum (F.). However, the use of a net did not affect other predatory (Carabidae) and parasitic (Ichneumonidae and Tachinidae) entomofauna.