Gut bacterial communities of Lymantria xylina and their associations with host development and diets

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 <em>Lymantria xylina</em> 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 <em>L. xylina</em> fed on different diets varied significantly, but did not change during different development periods. This seemed to indicate that vertical inheritance occurred in <em>L. xylina</em> mutualistic symbionts. <em>Acinetobacter</em> and <em>Enterococcus</em> were dominant in/on eggs. In the first instar larvae, <em>Acinetobacter</em> accounted for 33.52% of the sterilized artificial diet treatment, while <em>Enterococcus </em>(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 <em>L. xylina</em> and might provide new possibilities for improving the control of these bacteria.