LABORATORY EVALUATION OF PROMISING SYSTEMIC INSECTICIDES IN GUINEA PIGS AGAINST ORIENTAL RAT FLEAS.

Abstract

Fourteen systemic insecticides administered orally caused complete mortality of oriental rat fleas, Xenopsylla cheopis (Rothschild), without noticeably affecting the guinea pigs. These compounds and the lowest effective dosages were: American Cyanamid 12503, O,O -diethyl O -[6-(3(2- phcnyl) -pyridazinonyl) ] phosphorothioate, 200 mg/kg; American Cyanamid 18706, S -ethylcarbamoylmethyl O,O - dimethyl phosphorodithioate, 100 mg/kg; American Cyanamid CL-26691, O,O -dimethyl O-p -sulfamoylphenyl phosphorothioate, 5 mg/kg; American Cyanamid CL-28865, dimethyl p -sulfamoylphenyl phosphate, 25 mg/kg; Famophos, O-p- - (dimethylsulfamoyl)phenyl O,O -dimethyl phosphorothioate, 100 mg/kg; American Cyanamid CL-38106, O,O -dimethyl O-[p- (methylsulfamoyl)phenyl] phosphorothioate, 25 mg/kg; Bayer 23655, O,O -dimethyl- S - (2-isopropyl) ethylsulfinyl thiolphosphate, 50 mg/kg; Bayer 25198, O,O -dhnethyl O -£-methylsulfinyl)phenyl phosphorothioate, 100 mg/kg; fenthion, 50 mg/kg; butonate, 50 mg/kg; dimethoate, 100 mg/kg; Monsanto CP-12432, dimethyl (1-hydroxyvinyl)phosphonate diethyl phosphate, 200 mg/kg; Vamidoate, O,O -dimethyl S -[2-[(1-methylcarbamoylethyl) thio]ethyl] phosphorodithioate, 25 mg/kg; and trichlorfon, 100 mg/kg. Three other compounds killed all the fleas, but also killed the guinea pigs. These compounds with the lowest effective dosages were: American Cyanamid CL-38064, O-p -(ethylsulfamoyl)phenyl O,O dimethyl phosphorothioate, 25 mg/kg; Meta-Systox-R®, S -2- (ethylsulfinyl)ethyl O,O -dimethyl phosphorothioate, 200 mg/kg; and diazinon, 400 mg/kg.