RNAi for management of Asian long-horned beetle, Anoplophora glabripennis: identification of target genes

The Asian long-horned beetle (ALB), Anoplophora glabripennis, is a serious invasive forest pest in several countries, including the USA. Currently, there are no effective methods available to manage this pest without adverse impacts on the environment, but RNA interference (RNAi) technology may provide a more environmentally friendly pest control option. To identify target genes for control of ALB, we screened 48 candidate genes in larvae and selected several effective target genes. Injection of double-stranded RNA (dsRNA) targeting the gene coding for the inhibitor of apoptosis (dsIAP) or vacuolar sorting protein, SNF7 (dsSNF7), into larvae and adults resulted in a significant knockdown of these genes and caused 100% mortality in both larvae and adults. As microinjection of dsRNA is not a feasible option for field applications, delivery through oral route was then attempted. Oral delivery of naked dsRNA did not cause mortality in larvae and adults. However, feeding heat-killed bacteria containing dsIAP or dsSNF7 induced mortality and knockdown of target genes in larvae and adults. In conclusion, the utilization of heat-killed bacteria for delivery of dsRNA targeting IAP or SNF7 gene may serve as a potential pest control method for ALB.