Appraisal of quantitative losses caused by Trogoderma granarium (Everts) and Tribolium castaneum (Herbst) in different genotypes of wheat,rice and maize during storage

The storage of agricultural commodities is carried out for numerous reasons and there are many factors affecting safe storage,the most important of them are the insect pests. in the present investigation genotypes of wheat (arri-11,millat-11,punjab-11),maize (kobras,kermess,702) and rice (super basmati,basmati 86 and basmati 515) were evaluated for their resistance or susceptibility level against trogoderma granarium (everts) and tribolium castaneum (herbst). the results were evaluated on the bases of weight loss percentage and their progeny on larval numbers. the overall results revealed that none of the genotype was completely resistance to the infestation caused by t. granarium and t. castaneum. all these tested genotypes varied significantly in their degree of resistance in term of infestation percentage and development of progeny. on the basis of percent damage,the least damage 2.43% (t. castaneum) and 4.02% (t. granarium) was observed in maize,followed by rice 3.99% (t. castaneum) and 5.69% (t. granarium),and highest damage was noted in wheat 5.43% (t. castaneum) and 7.96% (t. granarium) genotypes. the weight loss was highest after 90 days of exposure in all the genotypes. while the results regarding the pest population progeny development was in such order; wheat > rice > maize,hence these genotypes were designated as the most tolerant and most susceptible genotypes.