Effect of insecticide-treated trap logs and lure traps for Ips typographus (Coleoptera: Curculionidae) management on nontarget arthropods catching in Norway spruce stands

Abstract

The numbers of nontarget arthropods captured by Theysohn pheromone traps (TPTs) and insecticide-treated tripod trap logs (TRIPODs) were compared; both kinds of traps were baited with pheromone lures Pheagr IT for Ips typographus. In 2010, 15 TPTs and 15 TRIPODs were deployed (with a 10-m spacing) in a forest in the northeastern Czech Republic. The TPTs and TRIPODs were inspected weekly during the entire period of I. typographus flight activity (30 April–1 October). The TRIPODs were sprayed with Vaztak 10 SC insecticide every 7 weeks; at each spraying, the pheromone evaporators were renewed. Higher numbers of entomophagous arthropods, including the predacious beetles Thanasimus formicarius and T. femoralis, were captured by the TRIPODs than by the TPTs. The number of Thanasimus spp. captured by TRIPODs was especially high at the end of April. The efficacy of TRIPODs for the control of I. typographus could be maintained while the kill of nontarget organisms could be reduced by deploying the evaporators 1 week later (in early May rather than in late April) in relation to the recommended date of dispenser installation.