Targeting V-ATPase B with synthetic small peptide impairs fitness, development, and feeding behaviour of Thrips palmi (Thysanoptera: Thripidae).

Thrips palmi Karny (Thysanoptera: Thripidae) is a major pest of economically imporant field and horticultural crops, contributing to substantial yield losses and serving as a vector for several plant viruses. Developing novel strategies to enhance plant resistance to T. palmi and associated viral diseases is critical. In this study, we investigated the potential of small synthetic peptides targeting the V-type proton ATPase subunit B (V-ATPase B), a highly conserved protein essential for intracellular vesicle acidification and ATPase function, to disrupt critical physiological processes in thrips. A small peptide was designed targeting V-ATPase B and orally delivered to both larvae and adults, mixed with an artificial diet. Mortality assays revealed a dose-dependent increase in thrips mortality, with the highest concentration (100 nmol) causing up to 97.78% mortality in larvae and adults across time intervals ranging from 6 h to 4 days post-treatment, compared to thrips fed with an artificial diet with a non-specific peptide and without small peptide. Peptide treatment resulted in noticeable morphological deformities at both developmental stages. Interestingly, treated thrips showed reduced feeding activity on eggplant, suggesting a blockade of physiological processes. The findings suggested that the small synthetic peptide targeting V-ATPase B disrupted essential biological functions in T. palmi, offering a promising approach for thrips management.