Comparative toxicity of four halogenated organophosphorus insecticides to chicks, Japanese quail, and diptera.

Abstract

The toxicity cockerels and Japanese quail of SD-9020 ( O -[2-chloro-1-(2,4-dichlorophenyl) vinyl] O, O -dimethyl phosphorothioate), SD-8280 (2-chloro-1-(2,4•dichlorophenyl) vinyl dimethyl phosphate), SD-8436 (2-chloro-1-(2,4-dibromophenyl) vinyl dimethyl phosphate), and SD-8211 (2-chloro-1-(2,5-dichlorophenyl) vinyl dimethyl phosphate) was determined. Although the relative order of acute oral toxicity of insecticides to both avian species was the same (SD-8280 = SD-9020 > SD > 8436 > SD-8211) the cockerels were more susceptible than the Japanese quail. There was no difference in susceptibility between sexes of the quail. Subacute toxicity of these insecticides to the chick including the effect on blood plasma cholinesterase was investigated. Relatively little inhibition of cholinesterase was detected except in those chicks receiving 800 ppm of SD-9020. The toxicity to larvae of the house fly, Musca domestica L., Fannia pusio (Wiedemann), Chrysomya megacephala (F.), and Parasarcophaga argyrostoma (Robineau-Desvoidy), of droppings from these chicks were compared with the toxicity to larvae of droppings directly with these insecticides. Droppings from the SD-9020-treated chicks were the most toxic, causing 100% mortality in the larvae of all species at the lowest concentration fed, 50 ppm. Droppings directly inoculated with SD-9020 also were generally the most toxic, larvicidal. The larvae of the house fly were particularly susceptible to manure containing these insecticides, while the larvae of P. argyrostoma were the least susceptible. The subchronic toxicity of the insecticides to the Japanese quail also was investigated. There appeared to he a significant mortality among quail receiving SD-9020 in the feed, but there was no adverse effect from any of the insecticidal treatments on body weight gain or feed conversion. However, egg production was depressed by SD-9020 and SD-8280. The insecticides, in general, did not affect fertility with the possible exception of hens receiving 800 ppm of SD-9020 and SD-8436. Hatchability of fertile eggs was not affected, nor was there any indication of teratogenic effects. The differential maggot and avian toxicity appears great enough to warrant long-range feeding studies to determine the chronic toxicity to hens and residue deposits in eggs and tissues of several of these insecticides.