Evaluation of pheromone-baited traps for monitoring of cucujid and tenebrionid beetles in stored grain

Plastic probe traps, corrugated cardboard traps, and weighing boat traps, either pheromone baited or unbaited, were tested for their efficacy in recapturing adults of six species of stored grain beetles released in lots of 100 into bins containing 60 kg of wheat. Probe traps were generally superior, although there were instances in which either or both of the other trap types were competitive with probe traps. Pheromone baits (cucujolides) improved the efficiency of one or more of the trap types for the cucujids Oryzaephilus surinamensis (L.), O. mercator (Fauvel), Cryptolestes ferrugineus (Stephens), and C. pusillus (Schonherr). However, a (+/-)-4,8-dimethyldecanal bait did not improve the efficacy of any trap type for the tenebrionids Tribolium castaneum (Herbst) or T. confusus Jacquelin du Val. The results suggest that for each target species, pheromone, trap type, and habitat, the development of optimal monitoring programs should be based on independent and rigorous experimental evaluation