A laboratory evaluation of pirimiphos methyl and difluron admixed with wheat against the granary weevil

Abstract

Maldison, pirimiphos methyl, and difluron were tested against the granary weevil (Sitophilus granarius (L.)). Piriphos methyl, LC95 0.75 ppm, was considerably more active than maldison LC95 3.4 ppm. As difluron acts by inhibiting cuticle formation, It was not active against adult weevils. Insecticide concentrations giving a 95% reduction in the F1 generation population over the control treatments, were: pirimiphos methyl 0.5 ppm, difluron 1.9 ppm, and maldison 2.0 ppm. Pirimiphos methyl was the most cost effective compound tested. a method for assessing the evenness of distribution of insecticide dust through grain is also presented.

Keywords:

• maldison
• pirimiphos methyl
• difluron
• stored-products insects
• insect control
• cuticle formation
• granary weevil
• Sitophilus granarius
• insecticide resistance
• insecticide