RNAi-Based Insecticide Target Screening: Four Genes Critical for Cuticular Pigmentation and Molting in Beetles

Area of Science:

• Entomology
• Molecular Biology
• Pest Management

Background:

• Chemical pesticides pose environmental risks for controlling the destructive pine-boring pest, Monochamus alternatus.
• RNA interference (RNAi) presents a promising eco-friendly alternative for pest control.
• Identifying specific genes crucial for pest survival is key to developing effective RNAi strategies.

Purpose of the Study:

• To screen and identify novel RNAi target genes in Monochamus alternatus.
• To investigate the function of cuticle-associated genes involved in pigmentation and molting.
• To evaluate the potential of these genes for developing RNAi-based pesticides.

Main Methods:

• Gene silencing using RNA interference (RNAi) targeting specific genes in Monochamus alternatus.
• Investigating the effects of gene silencing on larval and pupal development, molting, and pigmentation.
• Assessing mortality rates and dose-dependent effects of gene silencing.

Main Results:

• Silencing tyrosine hydroxylase (TH) resulted in albinism and significant adult mortality (74.8%).
• Targeting ultraspiracle (USP) disrupted molting in larvae, causing 77.6%–87.9% mortality.
• Silencing chitin deacetylase 2a/2b (CDA2a/2b) led to lethal molting defects, with CDA2b silencing showing the highest efficacy (95.8% mortality).

Conclusions:

• Four genes (TH, USP, CDA2a, CDA2b) are identified as potent targets for RNAi-based pest control in Monochamus alternatus.
• RNAi targeting these genes offers a viable, eco-friendly alternative to chemical pesticides.
• The findings provide a foundation for developing novel RNAi strategies applicable to other agricultural pests.