Development of efficient RNAi methods in the corn leafhopper Dalbulus maidis, a promising application for pest control

BACKGROUNDThe corn leafhopper Dalbulus maidis is the main vector of three important stunting pathogens that affect maize production. The most common control strategy against this species is the use of insecticides that provide minimal, short-term protection. In this context, genomic-based technologies such as RNA interference (RNAi) could be a suitable approach to control this pest in a highly specific manner, avoiding the adverse effects associated with insecticide misuse. Therefore, the objective of the present work was to assess the application of RNAi on D. maidis through different dsRNA delivery methods and known the function of target gene, Bicaudal C (BicC). RESULTSWe have identified and characterized the core components of the RNAi machinery in silico and established two methods of exogenous double-stranded RNAs (dsRNA) delivery to D. maidis. BicC -an important regulator of insect oogenesis-dsRNA was successfully delivered via injection or ingestion to adult females, causing significant reductions in the transcript levels and ovipositions and observable phenotypes in the ovaries when compared to control females. The small doses of dsRNABicC administered were enough to trigger a strong RNAi response, demonstrating that D. maidis is highly sensitive to RNAi. CONCLUSIONThis is, to our knowledge, the first report describing RNAi application in D. maidis, a tool that can be used to advance towards a novel, insecticide-free control strategy against this pest.