Acetone extracts of mace and nutmeg applied topically at dosages up to 50μg/insect were nontoxic to cowpea weevils, Callosobruchus maculatus (F.), slightly toxic to cigarette beetles, Lasioderma serricorne (F.), and confused flour beetles, Tribolium confusum Jacquelin du Val, and moderately toxic to rice weevils, Sitophilus oryzae (L.). Initially, both extracts showed strong repellency to rice weevils on surface-treated wheat at 2000 ppm for mace and 2000, 1000, and 500 ppm for nutmeg, although the repellency deteriorated rapidly. However, similarly treatd wheat greatly reduced the number of F1 progeny of rice weevils. This reduction decreased gradually. At 23 weeks after treatment, only the 2000 ppm dose of mace and nutmeg extract-treated wheat gave a significant reduction of the F1 generation when compared with the untreated control.
Varietal susceptibility on maize varieties against flour beetles (Tribolium casteneum and Tribolium confusum)
