Efficacy of layer treatment with methoprene for control of Rhyzopertha dominica (Coleoptera: Bostrychidae) on wheat, rice and maize

BACKGROUND: Insect growth regulators are promising alternatives to traditional pesticides in stored grain. The efficacy of the juvenile hormone analogue methoprene was evaluated as a layer treatment in a laboratory experiment for control of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) in wheat, rice and maize. RESULTS: Adults of R. dominica were placed in vials containing 33, 26 and 29 g (to a depth of 6.5 cm) of wheat, rice and maize, respectively, that was entirely or partially treated with 1, 5 or 10mg kg(-1) methoprene. In wheat and rice, the layer treatments were not as effective as the whole-grain treatment, but there was decreased progeny production as the application rate increased. However, onmaize the partial treatmentswere as effective as the whole-grain treatment at 5 and 10 mg kg(-1). CONCLUSIONS: The results suggest that partial layer treatments with methoprene can be used to control R. dominica on maize butmay not be effective for control of this species on wheat and rice. (C) 2011 Society of Chemical Industry