Investigating the damage potential of clouded plant bugs (Neurocolpus nubilus (Say)) in ThryvOn cotton

The clouded plant bug (Neurocolpus nubilus (Say)) is a documented pest of cotton (Gossypium hirsutum L.) present in ten cotton producing states, including Tennessee. Cotton expressing the Bacillus thuringiensis (Bt) Mpp51Aa2 protein, known as ThryvOn™ Technology, was fully commercialized in the United States for the 2023 growing season. Previous research has shown this insecticidal crystal protein to be effective against thrips and various plant bugs, including tarnished plant bugs, western tarnished plant bugs, and cotton fleahoppers, with piercing-sucking feeding behaviors. The impact of Mpp51Aa2 on clouded plant bugs is currently unknown. The primary objective of this study was to assess the impact of cotton expressing Mpp51Aa2 on clouded plant bug feeding on cotton squares and bolls. A no-choice caged feeding assay was conducted with adult and late instar clouded plant bug nymphs on cotton fruiting branches to assess the impact of clouded plant bug feeding on ThryvOn and non-ThryvOn square retention under controlled greenhouse conditions. A no-choice caged feeding assay was also conducted with clouded plant bugs on cotton bolls in a field setting to investigate the impacts of the ThryvOn trait and boll age on clouded plant bug feeding. Preliminary data from this field study will be presented. The information gained from these studies is critical for the development of management guidelines in Tennessee for clouded plant bugs in this newly commercialized cotton technology.