Leaf oil of Psidium guajava L.obtained from Soxhlet extraction was tested for insecticidal effect and phytochemical screening against khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae). In the laboratory study, groundnut seeds treated with the oil significantly performed better than the control in terms of reduced population and emergence of T. granarium larvae and adults. Percentage mortality of T. granarium in groundnut seeds treated with the oil increased with rate of treatment. The application of the oil at the rate of 0.5 ml gave significantly (p<0.05) higher percentage mortality than the control. Percentage seed weight loss caused by the larvae in 0.5 ml was significantly lower than 30 and 45% observed in 0.3 ml at 30 and 60 DAT respectively. The presence of flavonoids, alkaloids, steroids, triterpenoids, cynogenic glycosides, in various amounts is an indication of insecticidal properties of the oil. Lipids and carbohydrates offered reliable nutritional components of the guava oil. Oxalates, tannins, saponins and phenols were absent in the studied leaf oil. Guava leaf oil could form a reliable component of pest management programme against T. granarium in small scale storage of groundnut seeds.
