Lai Shengchang, Jiang Nan, Wang Jianguo, Zhou Yang, Yu Xiaohang, Wu Yaping, Yang Jinhua, Dai LuLu, Hao Dejun
Forest Protection, Forestry College, Nanjing Forestry University, Nanjing, China.
Forestry College, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
J Econ Entomol. 2024 Dec 28;117(6):2505-2517. doi: 10.1093/jee/toae186.
Native to Asia, Euwallacea interjectus (Blandford) (Coleoptera: Curculionidae: Scolytinae) is a destructive and invasive pest of live trees, and now it has been found in the United States and Argentina. In recent years, this pest appeared in high densities in poplar monocultures from Eastern China (Jiangsu and Shanghai) and Argentina and caused significant poplar mortality. However, the origin of the pests related to tree damage and the Fusarium mutualists from some poplar zones in China remained unclear. Here, we provided a broader phylogeographic analysis of E. interjectus based on the mitochondrial gene (cytochrome c oxidase I) to determine the global genetic structure of this species. Five mitochondrial lineages were found in the native area. Populations introduced to the United States were originated from 4 localities. The Argentine population was derived from Japan. The species was observed with strikingly high level of cytochrome c oxidase I intraspecific divergence that exceeded interspecific divergence, but the high intraspecific variation was correlated with geographical locations among the native populations. Two nuclear genes (arginine kinase and carbamoyl-phosphate synthetase 2-aspartate transcarbamylase-dihydroorotase) were more conservative, and intraspecific differences were lower than interspecific differences. The mitochondrial genetic variation was probably caused by evolution of lineages among geographically isolated populations. But it is immature to infer the existence of cryptic species based on cytochrome c oxidase I differences. All samples collected from poplar populations were indigenous and formed close relationship with a specimen from eastern and southern China. Surprisingly, pests from poplar populations in Jiangsu and Shanghai showed different haplotypes and mutualists. This suggested that the control strategies should consider the genetic and mutualistic diversity of beetles at different poplar localities.
亚洲产的暗褐断眼天牛（Euwallacea interjectus (Blandford)，鞘翅目：象甲科：小蠹亚科）是一种对活树具有破坏性的入侵害虫，现已在美国和阿根廷被发现。近年来，这种害虫在中国东部（江苏和上海）以及阿根廷的杨树单一栽培林中高密度出现，导致杨树大量死亡。然而，与中国一些杨树种植区树木损害相关的害虫以及与其共生的镰刀菌的起源仍不清楚。在此，我们基于线粒体基因（细胞色素c氧化酶I）对暗褐断眼天牛进行了更广泛的系统地理学分析，以确定该物种的全球遗传结构。在其原生地发现了五个线粒体谱系。引入美国的种群源自4个地点。阿根廷的种群源自日本。该物种细胞色素c氧化酶I的种内差异水平极高，超过了种间差异，但种内的高变异与原生种群之间的地理位置相关。两个核基因（精氨酸激酶和氨甲酰磷酸合成酶2 - 天冬氨酸转氨甲酰酶 - 二氢乳清酸酶）更为保守，种内差异低于种间差异。线粒体遗传变异可能是由地理隔离种群间谱系的进化引起的。但基于细胞色素c氧化酶I的差异推断隐存种的存在还不成熟。从杨树种群中采集的所有样本都是本地的，并且与来自中国东部和南部的一个标本形成了密切关系。令人惊讶的是，江苏和上海杨树种群中的害虫表现出不同的单倍型和共生菌。这表明防治策略应考虑不同杨树种植区甲虫的遗传和共生多样性。
