Species boundary and phylogeographical pattern provide new insights into the management efforts of Megacopta cribraria (Hemiptera: Plataspidae), a bean bug invading North America.

Abstract

Correct identification together with information on distribution range, geographical origin and evolutionary history are the necessary basis for the management and control of invasive species. The bean bug Megacopta cribraria is a crucial agricultural pest of soybean. Recently, M. cribraria has invaded the United States and spread rapidly, causing severe reductions in soybean yields. However, the species boundary and phylogeographical pattern of this invasive bean bug are still unclear. The results of different species delimitation methods (Automatic Barcode Gap Discovery, Assemble Species by Automatic Partitioning, Bayesian Poisson Tree Processes and Bayesian Phylogenetics and Phylogeography) strongly demonstrated that M. cribraria and Megacopta punctatissima represent the same species. M. punctatissima should not be considered a distinct species but rather a variety of M. cribraria. Phylogenetic analyses revealed three well-supported clades (Southeast Asia [SEA], East Asia continent [EAC] and Japan [JA]) with distinct geographical structures in the M. cribraria-M. punctatissima complex. The SEA clade was at the base of the phylogenetic tree, and the sister relationship between the EAC clade and JA clade was strongly supported. The split between the EAC clade and JA clade occurred at approximately 0.71 Ma, corresponding to the submergence period of the East China Sea land bridge. This study clarified the species boundary between M. cribraria and its closely related species and revealed the phylogeographical pattern and evolutionary history of M. cribraria. The species delimitation and phylogeography results achieved in this study could provide new insights into the monitoring and management of this agricultural pest. © 2022 Society of Chemical Industry.