The Promoting Effect of Gut Microbiota on Growth and Development of Red Palm Weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae) by Modulating Its Nutritional Metabolism

Abstract

Red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, is a destructive pest for palm trees worldwide. Recent studies have shown that RPW gut is colonized by microbes and alterations in gut microbiota can significantly modify its hemolymph nutrition content. However, the exact effects of gut microbiota on RPW phenotype and the underlying mechanisms remain elusive. Here germ-free (GF) RPW larvae were generated from dechorionated eggs which were reared on sterilized artificial food under axenic conditions. Compared with controls, the larval development of GF RPW individuals was markedly depressed and their body mass was reduced as well. Furthermore, the content of hemolymph protein, glucose and triglyceride were dropped significantly in GF RPW larvae. Interestingly, introducing gut microbiota into GF individuals could significantly increase the levels of the three nutrition indices. Additionally, it has also been demonstrated that RPW larvae monoassociated with Lactococcus lactis exhibited the same level of protein content with the CR (conventionally reared) insects while feeding Enterobacter cloacae to GF larvae increased their hemolymph triglyceride and glucose content markedly. Consequently, our findings suggest that gut microbiota profoundly affect the development of this pest by regulating its nutrition metabolism and different gut bacterial species show distinct impact on host physiology. Taken together, the establishment of GF and gnotobiotic RPW larvae will advance the elucidation of molecular mechanisms behind the interactions between RPW and its gut microbiota.

Neuropeptides and G-Protein Coupled Receptors (GPCRs) in the Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae)

“…The red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) is a devastating pest, which has been spread to various regions with palm trees in southern China, causing serious damage to the palm industry and landscape (Hou et al, 2011;Wang et al, 2015Wang et al, , 2017Muhammad et al, 2017;Ali et al, 2018). Red palm weevil larvae have a long life span, strong ability to drill collar, and strong adaptability to different environments (Shi et al, 2014;Peng et al, 2016;Dawadi et al, 2018;Habineza et al, 2019;Xiao et al, 2019). Due to damage to vascular tissues and consumption of large amounts of crown tissues, red palm weevil larvae can cause the death of palm trees (Butera et al, 2012;Muhammad et al, 2017).…”

Intestinal Microbiota Confer Protection by Priming the Immune System of Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae)

“…It is widely acknowledged that insects solely rely on a suite of innate immune responses, comprising cellular and humoral defense mechanisms, to fight pathogenic microbes (Shi et al, 2014). Presently, RPW has been found to live in the symbiotic associations with gut microbiota which is involved in its nutrition metabolism (Muhammad et al, 2017; Prosper et al, 2019). To our knowledge, it is still unknown about if and how commensal microbiota is involved in the proper immune function of insects outside dipteran insects.…”

Transcriptome and gene expression analysis ofRhynchophorus ferrugineus(Coleoptera: Curculionidae) during developmental stages

“…The weevil’s trunk-boring life style makes them hard to control ( Salama, Zaki & Abdel-Razek, 2009 ). Although multiple researches have been done to find new ways to control R. ferrugineus , including chemical agents ( Pugliese et al, 2017 ; Wakil et al, 2018 ), biological agents ( Zulkifli, Zakeri & Azmi, 2018 ), and intestinal microbes ( Habineza et al., 2019 ; Muhammad et al, 2019 ), the results are not effective. There are few studies on the molecular characteristics of R. ferrugineus , including transcriptome, genome structure and proteome ( Muhammad et al, 2019 ).…”

“…This feeding behavior renders detection of the pest difficult until it is already too late, and most traditional methods of pest control, including chemical pesticides, ineffective ( Ferry & Gomez, 2002 ; Faleiro, 2006 ; Faleiro et al, 2012 ). Recent studies showed that gut microbiota influenced the development of red palm weevil by regulating nutrient metabolism ( Habineza et al., 2019 ), and understanding the immune stimulating effect of intestinal commensal bacteria on larvae will be beneficial to the formulation of its control strategy ( Muhammad et al, 2019 ). The use of biological control methods to prevent the R. ferrugineus (mainly microbes) has achieved certain success, but the application still needs a long time ( Mazza et al, 2014 ).…”