LARVICIDAL CAPABILITY OF CHLOROFORM EXTRACTS OF Calophyllum inophyllum l. AND Cassia fistula L. ON Oryctes rhinoceros (LINN.) LARVAE in vitro

Owing to the fact that the application of chemical pesticides cause adverse effects on beneficial organisms, pollute the environment and are detrimental to human health, plant based products are being tested for the control of variety of insect pests. The present study was carried out to test and compare the bioefficacy of chloroform solvent extracts of Cassia fistula and Calophylluminophyllum against Orychtesrhinocerous larvae The leaves of these two plants were dried, powdered and extracted in a Soxhlet apparatus using chloroform as the solvent. These leaf extracts exhibited dose-dependent mortality. The rate of mortality also increases with the increasing hours of exposure indicates more sensitivity.The plant extracts alters the Total Hemocyte Count and Differential hemocyte count. The increased mortality may be due to its antifeedant activity or may be due to its altering the physiological activity and endocrine glands which secretes regulatory hormone.Of these two plants C. inophyllum is more effective than C. fistula.Thus from the work it is concluded C. fistula and C. inophyllum showed varying degree of toxicity and can be used in Integrated Pest Management of O.rhinocerous and minimise use of chemical insecticides.