Evaluation of Two Trap Log Techniques For Ambrosia Beetles (Coleoptera: Scolytidae) in Timber Processing Areas

Abstract

Two experiments evaluating the efficiency of pheromone-baited and blank, untreated or lindane-treated trap logs (logs) against pheromone-baited sticky traps (traps) as tools for management of ambrosia beetles were conducted in a Pacific coast dryland sorting area. Pheromone-baited or blank, untreated logs were as efficient as pheromone-baited traps for Trypodendron lineatum (Olivier) females early in the season and remained relatively efficient up to 4 weeks, after which they were inferior to traps. For the total 12-week experiment, pheromone-baited traps were more efficient than logs for male Gnathotrichus retusus LeConte, or blank logs for T. lineatum , and equal to logs for G. sulcatus LeConte. Pheromone-baited traps were more effective than lindane-treated logs throughout the 12-week experiment for female G. sulcatus . after 4 weeks for T. lineatum and male G. sulcatus , but only for 4 weeks in the middle of the experiment for G. retusus . For the total experiment, traps were superior to lindane-treated logs for G. sulcatus . whereas there was no significant difference for the other two species. Unbaited logs were inefficient. The use of untreated (no pesticide) logs early in the spring as a supplement to pheromone-baited traps would improve the efficiency of ambrosia beetle management in timber processing areas.