Botanical insecticides such as neem, pyrethrins and essential oils of many plants kill storage pests when applied at high levels but not equal in effectiveness to synthetic insecticides when applied at low levels (Sehgal and Ujagir, 1990). Initial research with proprietary materials suggests that diatomaceous earth (DE) a naturally occurring insecticidal desiccant can act as a synergist for botanical insecticides. DE is effective on grain by itself but is not desirable because the levels that are needed for food insect control reduces the test weight and value of the grain. The objectives of this study were: 1. To evaluate the efficacy of natural products from three broad catagories as grain protectants against four-stored product insect species; lesser grain borer, Rhyzopertha dominica (F.), rice weevil, Sitophilus oryzae (L), red flour beetle, Tribolium castanum (Herbst), and Indian meal moth, P/odia interpunctel/a. 2. To examine potential synergistic effect of natural products combined with diatomaceous earth, or DE
