Pirimiphos-methyl (organophosphate insecticide) is a post-harvest insecticide used on stored corn and sorghum grain and seed, incorporated into cattle ear tags, and used for the fogging treatment of iris bulbs. It is used to control various insects such as mealy bugs and mites (on iris bulbs), horn and face flies (on cattle), and cigarette beetle, confused flour beetle; corn sap beetle; flat grain beetle;
hairy fungus beetle; red flour beetle; sawtoothed beetle, granary weevil, maize weevil, merchant grain beetle, rice weevil, lesser grain borer, and angoumois grain moth, Indian Meal moth and almond moth
(on corn and sorghum grain and seed).
• Annual domestic use is low-- approximately 12,000 pounds of active ingredient per year. Total
usage is allocated mainly to stored corn grain (39%) ear tags for cattle/calves (36%), stored
sorghum grain (15%), corn seed (5%), and sorghum seed (5%). Regions with significant
usage on cattle include the Gulf Coast, Midwest, and West, and states with significant usage
on corn grain include Iowa and Texas.