Toxicity of extracts from three Tagetes against adults and larvae of yellow fever mosquito and Anopheles stephensi (Diptera: Culicidae).

Whole-plant Soxhlet extractions for the three Tagetes species showed that T. minuta had the greatest biocidal effect on the larvae and adults of Aedes aegypti (L.) and Anopheles stephensi Liston. Bioassays of simultaneous steam distillation extractions of the various parts of T. minuta found extracts from the flowers provided LD90s of 4 and 8 ppm against the larvae and 0.4 and 0.45% against the adults of A. aegypti and A. stephensi, respectively. Further research on T. minuta floral extracts as new biorational insecticides are discussed.