Did Acalolepta fraudatrix evolve Bursaphelenchus xylophilus, the pathogen of pine wilt disease?

分子系统发育分析表明，该线虫是由喜食阔叶树的B. xylophilus群线虫进化而来。这取决于将线虫从阔叶树传播到针叶树的天牛甲虫，也就是说，那些既可以利用阔叶树也可以利用针叶树作为寄主的树木。野外调查结果表明，能利用阔叶树和针叶树的假山茱萸（Acalolepta fraudatrix），能有效地传播木屑木属（Bursaphelenchus doui）。此外，室内实验还表明，阔叶树和针叶树的天牛都可以作为杜氏白蛉的媒介。因此，我们认为杜氏白蛉有可能由阔叶树传播到针叶树，再由假针叶树传播到假毛杉。

Molecular phylogenetic analyses show that Bursaphelenchus xylophilus evolved from B. xylophilus group nematodes that have a habitat preference for broad-leaved trees. This depends on cerambycid beetles (tribe Lamiini) that vector the nematodes from broad-leaved trees to conifers, namely, those that can use both broad-leaved trees and conifers as host trees. A field study showed that Acalolepta fraudatrix, which can use both broad-leaved trees and conifers, vectored Bursaphelenchus doui, a species in the B. xylophilus group. In addition, laboratory experiments indicated that B. doui could be vectored by both cerambycid beetles in broad-leaved trees and ones in conifers. Therefore, we suggest the possibility that B. doui was vectored from broad-leaved trees to conifers by A. fraudatrix, and then changed its vector from A. fraudatrix to Monochamus alternatus.