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The toxicity of certain aliphatic chlorinated hydrocarbons to Calandra granaria L. and other insects infesting grain
Author(s) -
Parkin E. A.
Publication year - 1946
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1946.tb06280.x
Subject(s) - fumigation , toxicity , trogoderma granarium , toxicology , biology , ethylene , larva , botany , agronomy , chemistry , organic chemistry , biochemistry , catalysis
An account is given of the biological data obtained during an investigation into the possibility of using certain aliphatic chlorinated hydrocarbons for fumigation of empty grain sacks infested by insects. The relative toxicity of three mixtures of chlorinated hydrocarbons to adult Calandra granaria , was ascertained: the best contained 3 parts ethylene dichloride and 1 part tetrachlorethylene by volume. Among seven species of insects likely to occur in empty sacks, the resistance of C. granaria adults to the 3: 1 mixture was exceeded only by that of Trogoderma granarium larvae. The toxicity of the mixture to C. granaria was determined over a range of concentrations and periods of exposure: at 20d̀ C and 70% R.H. a concentration × time product of about 1500 mg.‐hr./l. was required for 100% kill. These results were confirmed by inserting tubes containing weevils into bundles of sacks, which were then exposed to fumigant in a steel bin. The toxicity to adult C. granaria of mixtures containing different proportions of ethylene dichloride and tetrachlorethylene increased as the proportion of ethylene dichloride increased. The toxicity of tetrachlorethylene to the weevils was very low in relation to that of ethylene dichloride. The concentration × time product for 100 % kill of C. granaria at 20d̀ C. by ethylene dichloride alone was about 1100 mg.‐hr./1. The products for 50 % kill of C. granaria at 10, 15, 20 and 25d̀ C were in the proportion of 3.0: 2.0: 1.0: 0.7 respectively. Weevils which recovered from severe narcosis by the 3: 1 mixture were able to lay viable eggs.