Spinosad is an effective grain protectant against resistant strains of Rhyzopertha dominica (F.).

The article examines the efficacy of spinosad, a biologically derived insecticide against resistant strains of Rhyzopertha (R.) dominica, one of the most serious pests of stored grain. It highlights the problem of protectant resistance in R. dominica. It also discusses the potential role of spinosad in protecting stored grain and managing resistance. R. dominica has a history of developing resistance to grain protectants, and this is particularly well documented for Australia. Spinosad is clearly an excellent candidate for controlling resistant R. dominica. In Australia, where there is zero tolerance for live insects for export grain and some domestic markets, spinosad would be expected to allow the grain industry to meet this standard. A major advantage of the spinosad is its ability to control the prevalent organophosphorus resistant strains, and the less common synthetic pyrethroids and methoprene resistant strains. There is also potential for spinosad to be used to manage resistance development in R. dominica.