Fatty Acid Elongase Gene is Essential for Lipid Accumulation and Fecundity of (Acari: Tetranychidae).

RNA interference (RNAi) has been proposed as a promising strategy for sustainable and ecofriendly pest control. The insect cuticle lipids were deposited on the body surface and functioned as a defense against chemical xenobiotics. They consisted of aliphatic compounds, including free fatty acids (FFAs). However, elongase of very long chain fatty acids (ELOs) is essential for FFA biosynthesis; the function of ELO is still unknown in many arthropods, including (). In this study, three ELOs were cloned. Developmental-specific mRNA expression results revealed that three were highly expressed in egg and adult females. Whereas was dominantly expressed in adult females. Under spirobudiclofen stress, ELOs mRNA expression had different changes, and was down-regulated. The silencing of resulted in a dramatic reduction of oviposition and hatchability. Significant reduction of FFA contents was also examined within -repressed . In addition, we found that mRNA levels were related to fecundity and could affect triacylglycerol (TG) contents. The findings demonstrated that the introduction of ds via oral feeding induced the RNA interference-mediated silencing of a special target gene and could result in mortality and reproduction. In conclusion, is a special RNAi target for control, and its lethal mechanism might be disturbing lipids biosynthesis.