Comparison of Gut Bacterial Communities of <i>Locusta migratoria manilensis</i> (Meyen) Reared on Different Food Plants

Locusts, in particular <i>Locusta migratoria manilensis</i> (Meyen), have been associated with major damages in agriculture, forestry, and animal husbandry in China. At present, <i>L. migratoria manilensis</i> has been largely domesticated, being considered an edible insect in China. Feeding variety is one of the main characteristics of <i>L. migratoria manilensis</i>. It has been demonstrated that microorganisms inhabiting the insect gut impact nutrition, development, defense, and reproduction of the insect host. The aim of the present study was to search for the adaptation mechanism of <i>L. migratoria manilensis</i> feeding on four different food plants (goosegrass, maize leaves, soybean leaves, and pakchoi) and explore changes in the gut bacterial community structure of the insect at the fifth instar nymph stage. Proteobacteria and Firmicutes were the dominant phyla, whereas <i>Kluyvera</i>, <i>Enterobacter</i>, <i>Pseudocitrobacter</i>, <i>Klebsiella</i>, <i>Cronobacter</i>, <i>Citrobacter</i>, <i>Lactococcus</i>, and <i>Weissella</i> were the dominant genera in the gut of <i>L. migratoria manilensis</i>. Principal component analysis and permutational multivariate analysis of variance (PERMANOVA) revealed significant differences in the gut microbiota structure of <i>L. migratoria manilensis</i> fed on different food plants. Moreover, functional prediction analysis revealed that metabolic and cellular processes were the most enriched categories. Within the category of metabolic processes, the most enriched pathways were carbohydrate transport and metabolism; amino acid transport and metabolism; translation, ribosomal structure, and biogenesis; cell wall/membrane/envelope biogenesis; inorganic ion transport and metabolism; and energy production and conversion. Collectively, the present results revealed that the structure of gut bacterial communities in <i>L. migratoria manilensis</i> fed on different food plants is impacted by food plants, which may play an essential part in the adaptation of the host.