'Silencing of coatomer subunit beta disrupts development and causes mortality in the citrus root weevil Diaprepes...

Citrus root weevil, Diaprepes abbreviatus is one of the most destructive pests of citrus, causing extensive root damage that predisposes trees to secondary infection with phytophthora and substantial yield losses. In the present study, we identified and functionally characterized the coatomer subunit beta gene (DaCOPB), a core component of the COPI vesicle trafficking machinery responsible for two-way transport between the endoplasmic reticulum and Golgi apparatus.

The full-length DaCOPB transcript was obtained from the de novo transcriptome of D. abbreviatus and exhibited strong evolutionary conservation with insect homologs, including characteristic Armadillo repeat domains associated with protein-protein interactions. Developmental expression analysis revealed that DaCOPB is constitutively expressed across all life stages, suggesting an essential role in insect growth and development. To evaluate its functional importance, dsRNA targeting DaCOPB was orally delivered to larvae at multiple concentrations. RT-qPCR analysis performed 48 h post feeding confirmed significant suppression of DaCOPB transcripts relative to control treatments, demonstrating efficient RNAi-mediated gene silencing. Knockdown of DaCOPB resulted in severe developmental defects, including larval mortality, disrupted pupation, and malformed adults. Regression analysis further revealed a significant dose-dependent correlation between dsRNA exposure and the magnitude of gene suppression and phenotypic effects.

These results demonstrate that DaCOPB is necessary for normal development and survival for D. abbreviatus, highlighting its potential as a promising molecular target for RNAi-based pest management strategies aimed at controlling citrus root weevil populations. © 2026 Society of Chemical Industry.