How does RNAi work to control western corn rootworm (Diabrotica virgifera virgifera) larvae

Double-stranded RNA (dsRNA) is known to be effective in Diabrotica larvae via oral delivery. After ingestion, the dsRNA is thought to be taken up by the insect midgut cell and processed by the native RNAi machinery, which leads to specific knockdown of the target mRNA. The knockdown effect can cause lethality if the target mRNA encodes a protein with an essential function in the insect. Although processing of the dsRNA and target mRNA degradation appear to be conserved in western corn rootworm, some of the key steps in this process, such as uptake of dsRNA into midgut cells, are still unknown. In this presentation, we will present data on the dsRNA uptake mechanism and its selectivity for molecules of different sizes, as well as, the detailed morphological and cellular defects that lead to western corn rootworm (WCRW, Diabrotica virgifera virgifera) death upon ingestion of dsRNA targeting an essential gene.