Boil damage by southern green stink bug (Hemiptera : Pentatomidae) and tarnished plant bug (Hemiptera : Miridae) caged on transgenic Bacillus thuringiensis cotton

Damage to bells of transgenic Bacillus thuringiensis (Bt) cotton by souther n green stink bug, Ne;nra viridula (L.), and tarnished plant bug, Lygus lin eolaris (Palisot de Beauvois), was evaluated in field-cage studies. Fifth i nstars of N. viridula confined singly over a 9-d-old bell for 3.5 d caused more damage than adult stink bugs or earlier instars. Boil damage by 5th in stars of N, viridula decreased as bell age increased from 4 to 18 d from wh ite bloom; damage to 18-d-old bells was negligible. Exposure of 18-d-old be lls singly to 5th instars of N, viridula for 7 d reduced bell yield by 59% compared with unexposed bells. Adults of L. lineolaris caused bell injury s imilar in type to that of 4th instars of N, viridula after confinement of a dults singly with an 8-d-old bell for 8 d. However, the much larger 4th ins tars of N, viridula caused significantly more damage than adults of L. line olaris, These data should be particularly useful in the development of trea tment thresholds for the aforementioned pests in transgenic Bt cotton where insecticide use is limited.