author(s)
G Ajesh, CA Jayaprakas, Jithu U Krishnan and LS Rajeswari

abstract
In the midst of logarithmic human population explosion it is very critical for being vigilant in the use of food resource with a motto on sustainability. The Ministry of Food and Civil Supplies, Government of India has projected that a total preventable post-harvest losses of food grains is around 10% of the total production or about 20 MT, which is equivalent to the total food grains produced by Australia annually. Most of the chemical fumigants used for the disinfection of stored-product pests have been phased out due to their adverse effect to man and environment; hence globally there is an intensive search for alternative to synthetic fumigants. Cassava, Manihot esculenta Crantz is cultivated for their starchy tubers as food, feed and industrial purposes. Cyanogens are the major category among the many other bitter principles in cassava. Central Tuber Crops Research Institute (CTCRI), Thiruvananthapuram has isolated the cyanogen derivatives and standardised techniques for the generation of Cassava-Bio-Fumigant (CBF) from this plant against the insect pests in many horticultural crops. In the current investigation, CBF was isolated, toxicity estimated and tested against Tribolium castaneum and Rhyzopertha dominica and the lethal doses were standardised. LD₅₀ of CBF against the insect T. castaneum was higher over R. Dominica in experiments with food, without food and for respective larva. The CBF is more effective on treated insects in without food condition.