Gut Lignocellulose Activity and Microbiota in Asian Longhorned Beetle and Their Predicted Contribution to Larval Nutrition

Abstract

Anoplophora glabripennis (Asian longhorned beetle) is a wood-boring pest that can inhabit a wide range of healthy deciduous host trees in native and invaded areas. The gut microbiota plays important roles in the acquisition of nutrients for the growth and development of A. glabripennis larvae. Herein, we investigated the larval gut structure and studied the lignocellulose activity and microbial communities of the larval gut following feeding on different host trees. The larval gut was divided into foregut, midgut, and hindgut, of which the midgut is the longest, forming a single loop under itself. Microbial community composition and lignocellulose activity in larval gut extracts were correlated with host tree species. A. glabripennis larvae fed on the preferred host (Populus gansuensis) had higher lignocellulose activity and microbial diversity than larvae reared on either a secondary host (Salix babylonica) or a resistant host (Populus alba var. pyramidalis). Wolbachia was the most dominant bacteria in the gut of larvae fed on S. babylonica and P. alba var. pyramidalis, while Enterococcus and Gibbsiella were the most dominant in larvae fed on P. gansuensis, followed by Wolbachia. The lignocellulose-degrading fungus Fusarium solani was dominant in the larval gut fed on different host trees. Functional predictions of microbial communities in the larval gut fed on different resistant host trees suggested that they all play a role in degrading lignocellulose, detoxification, and fixing nitrogen, which likely contribute to the ability of these larvae to thrive in a broad range of host tree species.

Gut Bacteria of Wood-Boring Streltzoviella insularis and Their Involvement in Pinoresinol Degradation of Ash Tree (Fraxinus sp.) Host

“…Several S. insularis host tree species are present in this area, ,, yet the pest is mainly found on ash trees in this area. In addition, ten phloem samples were collected from the larval galleries (infested phloem) of the infested trees, and another ten phloem samples were collected from uninfested control trees for analysis of secondary metabolites.…”

“…This area is part of the "Millennium Forest" of Xiongan New Area, China's recent massive urban greenery project, aiming to reduce the impact of invasive species and increase the resilience of urban forests against them. 43 Several S. insularis host tree species are present in this area, 38,39,43 yet the pest is mainly found on ash trees in this area. In addition, ten phloem samples were collected from the larval galleries (infested phloem) of the infested trees, and another ten phloem samples were collected from uninfested control trees for analysis of secondary metabolites.…”

“…chinensis var. rhynchophylla , also called Korean ash). , Despite its common pest status, not much is known about the gut bacterial composition or function of S. insularis. To address this knowledge gap, we isolated and identified gut bacteria of S.…”

“…rhynchophylla, also called Korean ash). 39,40 Despite its common pest status, not much is known about the gut bacterial composition or function of S. insularis. 17 To address this knowledge gap, we isolated and identified gut bacteria of S. insularis larvae with culture-dependent methods and tested the influences of different pinoresinol concentrations on the survival and growth of S. insularis.…”

A Review of the Host Plant Location and Recognition Mechanisms of Asian Longhorn Beetle

“…pyramidalis and S. babylonica , Wolbachia was the predominant bacteria in the gut of larvae, while Bacteroidetes , Firmicutes , and Actinobacteria were predominant in larvae fed on a preferred host ( A . saccharum ) [ 136 , 137 ]. However, whether Wolbachia and Bacteroidetes influence the synthesis of cuticular hydrocarbons and mating of ALB has yet to be demonstrated.…”