INSECTICIDAL LIMONOIDS FROM SWIETENIA-HUMILIS AND CEDRELA-SALVADORENSIS

Four limonoids, humilinolides A-D from Swietenia humilis and cedrelano lide from Cedrela salvadorensis, were evaluated for their effect on th e European corn borer, Ostrinia nubilalis in comparison with toosendan din, a commercial insecticide derived from Melia azedarach. When incor porated into artificial diets of neonates at 50 ppm, all compounds cau sed larval mortality as well as growth reduction and increased the dev elopment time of survivors in a concentration-dependent manner. Humili nolide C also reduced growth and survivorship at 5 ppm. Additional eff ects observed in many of the limonoid-treated groups included a signif icant delay in time to pupation and adult emergence. The compounds sho wed comparable activity to toosendanin, a commercial insecticide. Furt hermore, the cytotoxicity of the humilinolides to three human cell lin es was low.