Figure 3

Response of Cotesia chilonis to pairs of odor sources in dual-choice tests using a Y-tube olfactometer.

Odor sources: 1^st non-Bt HD: non-Bt rice plants infested with 30 1^st-instar larvae of C. suppressalis, 1^st Bt HD: Bt rice plants infested with 30 1^st-instar larvae of C. suppressalis; and 3^rd non-Bt HD: non-Bt rice plants infested with 10 3^rd-instar larvae of C. suppressalis. Asterisks indicate a significant difference within a choice test: **P < 0.01; n.s. indicates a non-significant difference (P > 0.05) (χ² test). The bars indicate the percentages of parasitoids that selected either odor source. The numbers indicate the number of parasitoids that made a choice and the numbers in parentheses indicate the total number of parasitoids tested.