Fig. 1.

Feeding preference behavior of fifth instar H. armigera larvae, reared on normal artificial diet, strychnine diet or strophanthin-K diet (indicated along the horizontal axis), on cotton leaf disks or pepper fruit disks in choice assays between control and the two chemicals. a Strychnine on cotton leaf disks b strophanthin-K on cotton leaf disks; c strychnine on pepper fruit disks; d strophanthin-K on pepper fruit disks; e strychnine and strophanthin-K on pepper fruit disks. N = 20 in all tests. Vertical lines represent standard errors. Asterisks indicate significant differences between treated and control disks according to the paired-samples t test (*P < 0.01; **P < 0.001)