Boll Damage by Southern Green Stink Bug (Hemiptera: Pentatomidae) and Tarnished Plant Bug (Hemiptera: Miridae) Caged on Transgenic Bacillus thuringiensis Cotton

Abstract

Damage to bolls of transgenic Bacillus thuringiensis (Bt) cotton by southern green stink bug, Nezara viridula (L.), and tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), was evaluated in field-cage studies. Fifth instars of N. viridula confined singly over a 9-d-old boll for 3.5 d caused more damage than adult stink bugs or earlier instars. Boll damage by 5th instars of N. viridula decreased as boll age increased from 4 to 18 d from white bloom; damage to 18-d-old bolls was negligible. Exposure of 13-d-old bolls singly to 5th instars of N. viridula for 7 d reduced boll yield by 59% compared with unexposed bolls. Adults of L. lineolaris caused boll injury similar in type to that of 4th instars of N. viridula after confinement of adults singly with an 8-d-old boll for 8 d. However, the much larger 4th instars of N. viridula caused significantly more damage than adults of L. lineolaris. These data should be particularly useful in the development of treatment thresholds for the aforementioned pests in transgenic Bt cotton where insecticide use is limited.