In the laboratory, dichlorvos residues of 0.8 to 1.9 ppm on Soft Red Winter wheat produced 90 to 100% mortalities among the rice weevil adults, Sitophilus oryzae (L.), and reduced the number of progeny by 89% or more. Residues of 3.8 ppm or more provided 85% or more mortality of 3rd and 4th-instar larvae. Initial residues of 3.8 to 8.0 ppm decreased 89 to 76%, respectively in 28 days.