Chlorpyrifos-methyl is an organophosphate insecticide that induces 100, 100, 63, and 97.3% mortality of the adult stored-grain pestsL. bostrychophila, L. decolor, L. entomophila, andL. paeta, respectively, when applied to grain at a dose of 10 mg/kg.¹It also reduces the number of live progeny produced byL. bostrychophila, L. decolor, L. entomophila, andL. paetaby 100, 100, 30.4, and 41.1%, respectively, when applied to grain at a dose of 2.5 mg/kg. Chlorpyrifos-methyl (3 μM) reduces outgrowth of axon-like processes in mouse N2a neuroblastoma cells.²Administration of chlorpyrifos-methyl (4-100 mg/kg) to pregnant female mice decreasesH19gene methylation in sperm as well as decreases anogenital distance and increases thymus and epididymis weights and serum testosterone levels in male offspring.³Formulations containing chlorpyrifos-methyl have been used to control stored-grain pest and mosquito populations.

1.Nayak, M.K., and Daglish, G.J.Combined treatments of spinosad and chlorpyrifos-methyl for management of resistant psocid pests (Psocoptera: Liposcelididae) of stored grainPest Manag. Sci.63(1)104-109(2007) 2.Sachana, M., Flaskos, J., and Hargreaves, A.J.Effects of chlorpyrifos and chlorpyrifos-methyl on the outgrowth of axon-like processes, tubulin, and GAP-43 in N2a CellsToxicol. Mech. Methods15(6)405-410(2005) 3.Shin, H.S., Seo, J.H., Jeong, S.H., et al.Effect on the H19 gene methylation of sperm and organs of offspring after chlorpyrifos-methyl exposure during organogenesis periodEnviron. Toxicol.30(12)1355-1363(2015)