RNAi bioassays targeting bursicon reveal potential targets for pest control of Henosepilachna vigintioctopunctata

Henosepilachna vigintioctopunctata represents a significant economic pest, typically controlled through the use of chemical insecticides. The introduction of RNA interference (RNAi) technology has opened new avenues for biopesticide development, leading to the identification of various genes that are crucial for the growth and development of insects. However, the efficient screening of target genes in H. vigintioctopunctata remains limited. The present study provides a detailed investigation into the functional role of the neuropeptide Bursicon in H. vigintioctopunctata. The analysis of spatial distribution and developmental profiles demonstrated that two primary Bursicon subunits, HvBurs-α and HvBurs-β, exhibited specific expression patterns in the central nervous system, particularly peaking during the first-instar larval stage. Targeted RNAi of these genes led to a dramatic reduction in mRNA levels, resulting in reduced pupation and eclosion rates, along with nearly complete malformation, particularly concerning wing development. Experiments involving RNAi on second- and fourth-instar larvae showed significant reductions in the size of both elytra and hindwings in the adult forms, with the hindwings suffering severe shrinkage and lacking the ability to extend. Additionally, the combination of dsRNA treatment with chemical insecticides like avermectin or beta-cypermethrin increased larval mortality and adversely affected pupation and eclosion rates. Importantly, the application of dsRNA aimed at HvBurs-α and HvBurs-β did not adversely affect the predatory lady beetle Harmonia axyridis, suggesting a promising safety profile. Altogether, these findings underscore the critical role of Bursicon in wing development in H. vigintioctopunctata and highlight its potential as a promising target for RNAi-based biopesticide strategies, providing a novel and environmentally friendly approach to managing pest populations and their migratory behaviors.