RNA interference in halyomorpha halys, brown marmorated stink bug

Brown marmorated stink bug (BMSB), Halyomorpha halys, is a recently introduced highly polyphagous insect that is native to Eastern Asia. It was first introduced in Pennsylvania in 1996 and is currently found in 41 states. RNA interference (RNAi) has emerged as an efficient tool for the study of gene functions and as a potential insect control measure. RNAi is a process in which the introduction of double-stranded RNA (dsRNA) inhibits gene expression by degrading target mRNA. In this study we have silenced the expression of Vacuolar-ATPase (V-ATPase) and Catalase of BMSB. V-ATPase is an essential enzyme for hydrolysis of ATP and maintains membrane ion balance by transporting protons out of the cell. Catalase is an antioxidant enzyme that protects the insect from toxic forms of oxygen resulting from oxidative stress. To investigate the effectiveness of RNAi in H. halys we conducted microinjection method in adult insects. Green fluorescence protein (GFP) was used as a control. The expression of Catalase and V-ATPase were significantly down regulated at different time points (day 2, 4 and 6) when compared to the expression of GFP (p<0.05) by using real-time quantitative polymerase chain reaction (RT-qPCR). In addition to decreased expression, RNAi against V-ATPase and Catalase also showed higher mortality and lower fecundity than the control insects. This successful development of RNAi technique has considerable potential to evaluate gene function and pursue RNAi based control of BMSB.