Chlorfenapyr

Chlorfenapyr is a pyrrole pro-insecticide that is metabolized in vivo into CL 303268 by mixed function oxidases.¹ Chlorfenapyr increases respiratory activity in German cockroaches when used at concentrations ranging from 1 to 10 ?g per insect but has no effect on respiration in Sf9 cells when used at concentrations ranging from 1 to 100 ?M and does not affect respiration in isolated rat liver mitochondria up to a concentration of 10 ?M. Chlorfenapyr is active against a variety of insects including those susceptible and resistant to pyrethroid and organophosphate insecticides, including horn flies (H. irritans) as well as A. culicifacies and A. stephensi mosquitos that carry malaria (LC₅₀s = 2-2.39% suspension impregnated on paper).^2,3 Chlorfenapyr is lethal to rats with LD₅₀ values of 441 and 1,152 mg/kg for male and female rats, respectively.¹ Formulations containing chlorfenapyr have been used to control termites and in agriculture to control various insects.

1.Black, B.C., Hollingworth, R.M., Ahammadsahib, K.I., et al.Insecticidal action and mitochondrial uncoupling activity of AC-303,630 and related halogenated pyrrolesPestic. Biochem. Physiol.50(2)115-128(1994) 2.Sheppard, D.C., and Joyce, J.A.Increased susceptibility of pyrethroid-resistant horn flies (Diptera: Muscidae) to chlorfenapyrJ. Econ. Entomol.91(2)398-400(1998) 3.Raghavendra, K., Barik, T.K., Sharma, P., et al.Chlorfenapyr: A new insecticide with novel mode of action can control pyrethroid resistant malaria vectorsMalar. J.1016(2011)