Effect of Spinetoram on the Orientation of Tribolium Castaneum (Herbst) (Coleoptera: Tenebrionidae) (Red Flour Beetle) Adults to Pheromone Traps

Abstract

Tribolium castaneum (Red Flour Beetle) is a cosmopolitan storedproduct pest. Commercially available pheromone traps baited with its aggregation pheromone 4, 8-dimethyldecanal (4, 8 DMD) have a low trapping efficiency. Effects of biorational insecticides on orientation of T. castaneum have been reported. However, no such investigation has been carried out using spinetoram. Therefore, the objective of our study aimed to determine the effect of spinetoram on traps to catch of T. castaneum adults. The attraction of spinetoram pre-exposed to T. castaneum adults to pheromone traps were investigated under laboratory (experiment 1) and warehouse (experiment 2) conditions. Under laboratory conditions, the trapping of adults pre-exposed to spinetoram significantly differed from the respective control at each concentration. The highest trap catch (61.33%) was recorded on exposure to 31.25 ppm of spinetoram. The lowest trapping occurred at 0 ppm of spinetoram (water control). Under warehouse conditions, the highest trap catch was at 31.25 ppm and 46.875 ppm of spinetoram with no significant difference among them. The lowest trapping occurred at 0 ppm of spinetoram/ water control. The value obtained at 62.5 ppm was not significantly different from the value at 0 ppm. Our study showed that the pre-exposure to spinetoram enhanced the orientation of T. castaneum adults to pheromone traps baited with 4, 8 DMD, and the response was dose dependent. The observations made in this research may be useful in enhancing trapping efficiency of commercially available pheromone traps.