ENVS 3040 Lecture Notes - Lecture 5: Diamondback Moth, Secondary Metabolite, Insecticide

• School: University of Guelph
• Department: Environmental Sciences
• Course: ENVS 3040
• Professor: Rebecca Hallett

Document Summary

Botanical insecticides are insecticides that are produced by or derived from plants. Just because these co(cid:373)pou(cid:374)ds are (cid:374)aturally occurri(cid:374)g does(cid:374)"t (cid:373)ea(cid:374)t that they"re safer tha(cid:374) sy(cid:374)thetic co(cid:373)pou(cid:374)ds. Assess the acute toxicity of a compound using ld50 values. Describe the mode of action between bt and its delta-endotoxins. Discuss the advantages and limitations of botanical pesticides. A(cid:272)ute to(cid:454)i(cid:272)it(cid:455) is usuall(cid:455) e(cid:454)p(cid:396)essed i(cid:374) te(cid:396)(cid:373)s of it(cid:859)s ld50 (cid:448)alue (lethal dose to kill 50% of the test population). Pesticides that have a low ld50 for a target pest, and a high ld50 for non-target organisms are selective pesticides. The lower the ld50 value, the more toxic the compound is. Exposure refers to the amount of substance that an organism receives or comes in contact with. Pesticides must be applied in very specific ways and in specific amounts in order to be used correctly. The environmental impact quotient (eiq) helps us determine the environmental risk. It provides a measure of ecological impacts of pesticides.