Fig. 1.

(A) Scanning electron microscopy images of bacteria secreted onto leaves during feeding by CPB larvae after first feeding on an artificial diet with antibiotic (Right) or without antibiotic (Left). Damaged leaf tissues were prepared for SEM images 1 h after larval feeding. (Scale bar, 1 μm.) (B) Larval growth and (C) polyphenol oxidase (PPO) activities in plants damaged by larvae that fed on AB-treated or untreated leaves. Neonates were allowed to feed on excised leaflets from each treatment for 5 d and larval mass was determined. Values are means ± SEM. Different letters represent significant differences [ANOVA, P < 0.05; followed by LSD test; F_(2,71) = 6.63, P = 0.0023, n = 23–26]. PPO activities were measured on subsamples from each treatment 48 h after insect feeding [F_(2,9) = 27.13, P = 0.0002, n = 4]. To collect subsamples, two leaf discs from each of two leaves were pooled as one replicate. AB(−), plants damaged by untreated larvae; AB(+), plants damaged by AB-treated larvae; Con, undamaged plants.