Abstract

The non-availability of chemical insecticides due to the prevailing war conditions has induced Economic Entomologists in India to endeavour to find out suitable and efficient indigenous substitutes. During the investigations carried out at the Agricultural Research Institute, Coim- batore, Cherian and Ramachandran (1941) have reported that the kernels of Thevitia neriifolia Juss are found to possess insecticidal properties of a high order. In the course of these experiments there were indications that vegetable oil emulsions as a class possessed valuable insecticidal proper- ties. A considerable amount of valuable work has been done in other countries in respect of mineral oil emulsions but there is very little on record regarding investigation on the insecticidal properties of vegetable oil emulsions against crop pests. It was thought that such a study would be of material advantage in the field of economic entomology in Indis especially under the existing conditions when oils of mineral origin are ditficult to procure Accordingly studies were undertaken with castor oil, groundnut oil and neem (margosa) oil. This paper gives a short account of the preliminary trials conducted under laboratory conditions. The. information gathered so far, gives encouraging indications as to the possibi- lities of utilising such oil emulsions for the control of insect pests of crops.

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