ABSTRACT
Students will have the opportuity to test the effects of sinigrin on feeding by cabbage, turnip, and pea aphids. Students will become familiar with "choice test" and "no choice test" procedures for studying animal feeding, examine concentration effects, and develop dose response curves. Cabbage and turnip aphids are oligophagous, feeding entirely on plants within the family Cruciferae. Both species are pests of cabbage, turnip, radish, and other cole crops, and may be field-collected from these plants. One chemical which has been relatively well studied is the mustard oil glucoside, sinigrin. It has a number of effects, which differ with the life stage and species of feeding insect. Sinigrin stimulates stylet penetration into the phloem of the plant, and assists aphids in locating the phloem sieve elements, the primary aphid feeding site. If students have time, they may wish to rear one generation of turnip aphids on sinigrin-treated broadbean leaves, and compare these to those reared on the turnip host.
