Abstract

Investigations were carried out at Coimbatore during 1957-58 to evaluato the efficacy of treating cholam seeds with modern synthetic insecticides as a prophylactic measure against Sitophilus oryzae L. and Tribolium castaneum II., as this would provide a cheap and effective means of storing seed cholam. Two sets of experiments with ten treatments and four replications were conducted seperately for each pest over a period of one year with Co. 18 cholam seeds in a suitably randomised layout. Well cleaned cholam seeds were taken in one lb. lots in oloth bags and treated initially with the insecticide dusts of Aldrin 2%, Dieldrin 1.5% and Geigy-33 containing 10% DDT at dosages varying from 1:100 to 1:300 by weight. Twenty adults cach of S. oryzae and T. castaneum which wore bred in cholam in the laboratory were introduced per bag in each of the experiments at monthly intervals and the mortality counts of the respective insects were recorded every month.

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