Diversity Of Gut Bacteria In Larval Of Four Lepidopteran Insect Species

Insect gut bacteria were isolated in cotton bollworm Helicoverpa armigera, rice leaffolder Cnaphalocrocis medinalis, cabbage worm Pieris rapae and beet armyworm Spodoptera exigua.47different bacterium species were identified from the four insect species by16S rRNA sequence analysis. The biochemistry characteristics, hemolytic activity, sensitivity to antibiotics were also analyzed for several common bacterial isolates.1. Diversity of gut bacteria in the larval gut of H. armigera21bacterial species were identified from the larvae gut of H. armigera, most of the bacterial isolates belong to Bacilli, and the rest belong to β-Proteobacteria, a-Proteobacteria, y-Proteobactera, Actinobacteria, Sphingobacteria. The22isolates belong to12genera, Bacillus, Enterobacter, Enterococcus, Klebsiella, Massilia, Microbacterium, Micrococcus, Pseudomonas, Rhodococcus, Sphingobacterium, Sphingomonas, and Staphylococcus.2. Diversity of gut bacteria in the larval gut of C. medinalisFrom the gut of C. medinalis larvae25bacterial species were found, most of which belong to Bacilli and γ-Proteobactera, and the rest belong to α-Proteobacteria, β-Proteobacteria, Actinobacteria, Sphingobacteria.15genuses, which were Acinetobacter, Bacillus, Brevundimonas, Burkholderia, Enterococcus, Exiguobacterium, Hafnia, Klebsiella, Microbacterium, Micrococcus, Pseudomonas, Rhodococcus, Sphingobacterium, Staphylococcus, Streptomyces were identified.3. Diversity of gut bacteria in the larval gut of P. rapaeWe found18bacterial species from the gut of P. rapae larvae, these species fall within Bacilli, y-Proteobactera, a-Proteobacteria and Acinetobacter and belong to14genuses: Acinetobacter, Bacillus, Brevundimonas, Gordonia, Klebsiella, Microbacterium, Micrococcus, Paenibacillus, Planococcus, Pseudomonas, Psychrobacter, Sphingomonas, Staphylococcus, Virgibacillus.4. Diversity of gut bacteria in the larval gut of S. exiguaS. exigua larvae carry12bacterial species discovered in this research, most of them are Bacilli and α-Proteobactera, and least of them fell within Bacillus. These isolates are from8genera, which is Klebsiella, Kocuria, Micrococcus, Pseudomonas, Rhodococcus, Sphingomonas, Staphylococcus, Stenotrophomonas.5. Four lepidopteran insects had similar bacterial community in their gutThe guts of four insects harbored similar bacterial species.28bacterial species were isolated form only one insect species, which is Acinetobacter sp., Bacillus ginsengi, Bacillus nealsonii, Brevundimonas sp., Brevundimonas vesicularis, Burkholderia sp., Enterobacter sp., Exiguobacterium sp., Gordonia sp., Hafnia alvei, Kocuria rosea, Massilia timonae, Microbacterium foliorum, Microbacterium oxydans, Micrococcus lylae, Paenibacillus sp., Planococcus sp., Pseudomonas collierea, Pseudomonas oryzihabitans, Psychrobacter sp., Sphingobacterium kitahiroshimense, Sphingomonas aquatilis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus sciuri sp., Stenotrophomonas sp., Streptomyces scabiei, and Virgibacillus sp.. Other bacterial species could be isolated from more than one insect species. Micrococcus sp., Klebsiella sp.and Klebsiella pneumoniae were the most common gut bacterium species in our study, which were isolated from the gut of four lepidopteran species. Bacillus sp., Pseudomonas mosselii, Pseudomonas sp. and Staphylococcus sp. were found in three of the four species. Acinetobacter lwoffii, Enterococcus casseliflavus, Bacillus cereus, Bacillus flexus, Microbacterium sp., Pseudomonas geniculata, Rhodococcus erythropolis, Rhodococcus sp., Phingobacterium sp., Sphingomonas sp., Staphylococcus arlettae and Staphylococcus kloosii exist in two of the four species.6. Two new bacterial species were found in the gut of insects.It is the first report that Massilia timonae and Planococcus sp. were identified from insect gut. They were isolated from the gut of H. armigera, and P. rapae respectively.