Potential impact of the parasitising mite, Uropoda orbicularis, as a biological control agent for the red palm weevil, Rhynchophorus ferrugineus

Abstract

The invasive red palm weevil (RPW) Rhynchophorus ferrugineus is a major pest of palms worldwide. Developing biological control methods is a priority. This study investigated the potential of the mite Uropoda orbicularis as a biocontrol agent against RPW. Uropoda orbicularis mites were collected from RPW adults in a date palm plantation in Qena, Egypt during 2021 and 2022. Mite prevalence and abundance were quantified across various life stages and body parts of the RPW. Impacts of experimental mite infestation at different densities on RPW longevity, fecundity, feeding and egg viability were assessed. Mites significantly reduced RPW adult longevity (43–44%), number of eggs laid (64%) and egg hatching rate (25%), compared to non-infested controls. Feeding also declined with increasing mite density. Mites showed aggregation preferences with the highest abundance observed on the elytra and abdomen of adult hosts compared to other body parts. Moreover, adults hosted significantly more mites than pupae and larvae. An optimal mite density was found, beyond which mite mortality significantly increased. The observed reductions in RPW fitness parameters demonstrate the prospective biocontrol value of U. orbicularis against this major palm pest. Field studies are needed to validate the effectiveness of suppressing RPW populations. Overall, results provide novel evidence of an understudied mite–RPW trophic interaction with practical implications.