The Effect of Gut Bacteria on the Physiology of Red Palm Weevil, Rhynchophorus ferrugineus Olivier and Their Potential for the Control of This Pest

Abstract

Red Palm Weevil (RPW), Rhynchophorus ferrugineus Olivier, is a notorious pest, which infests palm trees and has caused great economic losses worldwide. At present, insecticide applications are still the main way to control this pest. However, pesticide resistance has been detected in the field populations of RPW. Thus, future management strategies based on the novel association biological control need be developed. Recent studies have shown that the intestinal tract of RPW is often colonized by multiple microbial species as mammals and model insects, and gut bacteria have been found to promote the growth, development and immune activity of RPW larvae by modulating nutrient metabolism. Furthermore, two peptidoglycan recognition proteins (PGRPs), PGRP-LB and PGRP-S1, can act as the negative regulators to modulate the intestinal immunity to maintain the homeostasis of gut bacteria in RPW larvae. Here, we summarized the current knowledge on the gut bacterial composition of RPW and their impact on the physiological traits of RPW larvae. In contrast with metazoans, it is much easier to make genetic engineered microbes to produce some active molecules against pests. From this perspective, because of the profound effects of gut bacteria on host phenotypes, it is promising to dissect the molecular mechanisms behind their effect on host physiology and facilitate the development of microbial resource-based management methods for pest control.

Omics in the Red Palm Weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae): A Bridge to the Pest

“…Additionally, insecticide resistance has been reported for decades, including in RPW populations [ 27 , 28 ]. In lieu of conventional methods, a series of ideas have been implemented to help eradicate the RPW and enable the survival of palm trees [ 29 ]. The Canary Islands of Spain have successfully eradicated red palm weevils using a series of scientifically-based programs supported by adequate resources [ 30 ].…”

The Intestinal Immune Defense System in Insects

“…It has been shown that the Drosophila intestinal clearance response to viruses relies on gut commensal bacteria to initiate the Imd signaling pathway as a means of activating the ERK signaling pathway in the gut [ 95 ]. Recent studies have also shown that the long red cone midge Rhodnius prolixus significantly enhances the immune response of the gut upon antibiotic treatment to remove intestinal bacteria by recolonizing S. marcescens or Rhodococcus rhodnii [ 96 , 97 ]. Ordinarily, intestinal commensal bacteria can protect the host by altering physiological functions, pH, and digestive enzyme levels in the gut and can also eliminate pathogens by competing with them for space and nutrients or by producing antibacterial substances [ 59 ].…”

Feeding Spodoptera exigua (Lepidoptera: Noctuidae) larvae with bacteria increase larval juvenile hormone levels inhibiting cannibalism under certain conditions

“…Larvae fed with different diets could be associated with different microbial communities in the gut. Gut microbes are correlated with host nutrient metabolism, supplementation of essential amino acids, and immunity [22][23][24][25] . The present study hypothesizes that S. exigua larval gut microbes are associated with host cannibalistic behavior.…”