Journal of Insect Science, (2017)17(6): 115; 1–7 doi: 10.1093/jisesa/iex089 Research Article Bacterial Communities Associated With the Pine Wilt Disease Vector Monochamus alternatus (Coleoptera: Cerambycidae) During Different Larval Instars Xia Hu,1 Ming Li,1 Kenneth F. Raffa,2 Qiaoyu Luo,1 Huijing Fu,1 Songqing Wu,1 Guanghong Liang,1 Rong Wang,1 and Feiping Zhang1,3 1College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China, 2Department of Entomology, University of Wisconsin-Madison, 345 Russell Labs 1630 Linden Dr., Madison, WI 53706, and 3Corresponding author, e-mail:
[email protected] Subject Editor: Campbell Mary and Lancette Josh Received 14 June 2017; Editorial decision 20 September 2017 Abstract We investigated the influence of larval instar on the structure of the gut bacterial community in the Japanese pine sawyer, Monochamus alternatus (Hope; Coleoptera: Cerambycidae). The diversity of the gut bacterial community in early, phloem-feeding larvae is significantly higher than in later, wood-feeding larvae. Many of these associates were assigned into a few taxonomic groups, of which Enterobacteriaceae was the most abundant order. The predominant bacterial genus varied during the five instars of larval development.Erwinia was the most abundant genus in the first and fifth instars,Enterobacter was predominant in the third and fourth instars, and the predominant genus in the second instars was in the Enterobacteriaceae (genus unclassified). Actinobacteria were reported in association with M. alternatus for the first time in this study. Cellulomonadaceae (Actinobacteria) was the second most abundant family in the first instar larvae (10.6%). These data contribute to our understanding of the relationships among gut bacteria and M.