TOXICITY AND REPELLENCY OF CHENOPODIUM OIL TO 4 SPECIES OF STORED-PRODUCT INSECTS

Chenopodium oil, an essential oil of Chenopodium ambrosioides L., was evaluated for its toxicity and repellency to adults of Callosobruchus machulatus (F.), Sitophilus oryzae (L.), Lasioderma serricorne (F.), and Tribolium confusum Jacquelin du Val. Topically applied, the oil was highly toxic to C. maculatus (100% mortality at 40-mu-g/insect) and L. serricorne (92.5% mortality at 50-mu-g/insect), moderately toxic to S. oryzae (52.5% mortality at 50-mu-g/insect), and only slightly toxic to T. confusum at 50-mu-g/insect. When applied to the surface of wheat, the oil was highly repellent to S. oryzae. When applied to wheat or black-eyed peas, the oil reduced infestations of S. orzyae and C. maculatus at dosages of 2000 and 1000 ppm, respectively.