Department of Entomology, Washington State University, Pullman, Washington, United States of America.
PLoS One. 2012;7(3):e34528. doi: 10.1371/journal.pone.0034528. Epub 2012 Mar 30.
The western tarnished plant bug Lygus hesperus is an economically important pest that belongs to a complex of morphologically similar species that makes identification problematic. The present study provides evidence for the use of DNA barcodes from populations of L. hesperus from the western United States of America for accurate identification.
METHODOLOGY/PRINCIPAL FINDINGS: This study reports DNA barcodes for 134 individuals of the western tarnished plant bug from alfalfa and strawberry agricultural fields in the western United States of America. Sequence divergence estimates of <3% reveal that morphologically variable individuals presumed to be L. hesperus were accurately identified. Paired estimates of F(st) and subsequent estimates of gene flow show that geographically distinct populations of L. hesperus are genetically similar. Therefore, our results support and reinforce the relatively recent (<100 years) migration of the western tarnished plant bug into agricultural habitats across the western United States.
CONCLUSIONS/SIGNIFICANCE: This study reveals that despite wide host plant usage and phenotypically plastic morphological traits, the commonly recognized western tarnished plant bug belongs to a single species, Lygus hesperus. In addition, no significant genetic structure was found for the geographically diverse populations of western tarnished plant bug used in this study.
西方玷污叶蝉（Lygus hesperus）是一种具有重要经济意义的害虫，属于形态相似的物种复合体，这使得鉴定变得困难。本研究为使用来自美国西部的西方玷污叶蝉种群的 DNA 条码进行准确鉴定提供了证据。
方法/主要发现：本研究报告了来自美国西部的苜蓿和草莓农业田地的 134 只西方玷污叶蝉个体的 DNA 条码。<3%的序列分歧估计表明，形态上可变的个体被准确识别为西方玷污叶蝉。配对的 F(st)估计值和随后的基因流动估计值表明，地理位置不同的西方玷污叶蝉种群在遗传上是相似的。因此，我们的研究结果支持并加强了西方玷污叶蝉相对较近（<100 年）向美国西部农业栖息地的迁移。
结论/意义：本研究表明，尽管西方玷污叶蝉广泛利用宿主植物并具有表型可塑性的形态特征，但普遍公认的西方玷污叶蝉属于单一物种，即 Lygus hesperus。此外，本研究中使用的地理上多样化的西方玷污叶蝉种群没有发现明显的遗传结构。
