Gut Bacterial Communities of Lymantria xylina and Their Associations with Host Development and Diet.

Qiuyu Ma,Rong Wang,Mulualem Tigabu,Guanghong Liang,Yonghong Cui,Meijiao Yang,Guoqiang Li,Xu Chu,Songqing Wu,Xia Hu,Feiping Zhang

doi:10.3390/microorganisms9091860

Abstract

The gut microbiota of insects has a wide range of effects on host nutrition, physiology, and behavior. The structure of gut microbiota may also be shaped by their environment, causing them to adjust to their hosts; thus, the objective of this study was to examine variations in the morphological traits and gut microbiota of Lymantria xylina in response to natural and artificial diets using high-throughput sequencing. Regarding morphology, the head widths for larvae fed on a sterilized artificial diet were smaller than for larvae fed on a non-sterilized host-plant diet in the early instars. The gut microbiota diversity of L. xylina fed on different diets varied significantly, but did not change during different development periods. This seemed to indicate that vertical inheritance occurred in L. xylina mutualistic symbionts. Acinetobacter and Enterococcus were dominant in/on eggs. In the first instar larvae, Acinetobacter accounted for 33.52% of the sterilized artificial diet treatment, while Enterococcus (67.88%) was the predominant bacteria for the non-sterilized host-plant diet treatment. Gut microbe structures were adapted to both diets through vertical inheritance and self-regulation. This study clarified the impacts of microbial symbiosis on L. xylina and might provide new possibilities for improving the control of these bacteria.

Highlights

The symbiotic association between bacteria and insects is a well-known and universal phenomenon, and is important in the biological processes of host insects
We hypothesized that L. xylina from all samples in this study would share specific bacteria, and that the bacterial community structure would have some associations with the organisms’ stage of development and diet; the objective of this study was to examine the variations in morphological traits and gut microbiota of L. xylina in response to natural and artificial diets
The gut microbiota of L. xylina fed on different diets were significantly different, and the diversity of the gut microbiota of L. xylina fed on SAC (2563 operational taxonomic units (OTUs)) was more abundant than for L. xylina fed on non-sterilized C. equisetifolia branch (NSC) (2178 OTUs)

Summary

Introduction

The symbiotic association between bacteria and insects is a well-known and universal phenomenon, and is important in the biological processes of host insects. In this symbiotic relationship, the gut microbiota is essential for maintaining insect health [1,2]. In stinkbugs of the family Plataspidae, gut bacteria were vertically transmitted as a ‘symbiont capsule’. When the ‘symbiont capsule’ was removed, the host insect showed high mortality rates [4]. The intestinal symbiotic bacteria of the oriental fruit fly Bactrocera dorsalis (Hendel) adjust the ecology and physiology of the host insect and even help host insects improve their resistance to insecticides [5]

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Conclusion