Development of novel biological treatment for palms against the red palm weevil (Rhynchophorus ferrugineus) using RNAi

Insect pests cost billions of dollars in the form of crop losses and insecticides, and farmers face an ever-present threat of insecticide resistance, fueling a continual search for alternative pest-control strategies. Thus, there is a long-felt need for environmentally friendly methods for controlling or eradicating insect infestation on or in plants, i.e., methods that are selective, environmentally inert, non-persistent, and biodegradable, that fit well into pest resistance management schemes. RNA interference (RNAi) is a process utilizing endogenous cellular pathways, whereby an interfering RNA molecule that is specific for a target gene sequence results in the degradation of the mRNA encoded. The red palm weevil (RPW; Rhynchophorus ferrugineus) is a wide spread pest considered as a major threat for dates and other palm tree species in the Middle East, Mediterranean, and around the word. The RPW larvae excavate holes in the trunk of the tree, feed from it and eventually causing the death of the palm host. Although some available pesticides are used to control the infestation, the synthetic pesticides had failed so far to stop the infestation and the use of such chemicals has detrimental effects on the food safety and the environment. Here, we present an alternative RNAi biological treatment for palms based on a double-stranded RNA (ds02288) sequence of the protea some sub unit beta type-1 (PSMB1). ds02288 showed high efficacy against RPW larvae in feeding assays and was able to prevent and reduce infestation in treated date-palm trees in field trials. Our product is currently pending registration in Israel as a new bio-pesticide for the management of RPW in date-palm trees.