The Japanese pine sawyer, Monochamus alternatus Hope, is the primary vector of the pinewood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, the causative agent of pine wilt disease in East Asia. The range of B. xylophilus expands through the dispersal capability of its vectors and transport of host trees infested with the pathogenic nematode and its vector. Outbreaks of M. alternatus populations occur together with the epidemics of pine wilt disease, because the insect reproduces on host trees recently killed by the disease. We measured some dispersal and life‐history traits of adults for four years to determine the change in flight capability and life history of a field population of beetles in relation to an outbreak. The population monitored exhibited an outbreak and subsequent collapse. The greatest mean body mass, largest area of hind wings, smallest wing load, and shortest preoviposition period were observed in the year of outbreak. By contrast, there was no difference in the ovariole number between pre‐outbreak (latent) and outbreak years. The greatest mean hind wing area and smallest wing load suggest likely result in greater flight performance. As other studies showed, adult body mass is related positively to the flight performance and oviposition rate. Moreover, a shortened preoviposition period leads to a high reproduction rate. Thus, adults in outbreak populations are “superdispersers” because they are likely to have enhanced flight capability and reproduction power. This suggests that M. alternatus populations at the onset of a population outbreak enhance the expansion rate of B. xylophilus range more than those during the latent and pre‐outbreak periods.

中文翻译：

---

Monochamus alternatus Hope 传播和生活史特征的逐年变化与爆发有关

日本松材锯木机 Monochamus alternatus Hope 是松材线虫 Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle 的主要媒介，它是东亚松树枯萎病的病原体。松材线虫的范围通过其载体的传播能力和被病原线虫及其载体侵染的宿主树的运输而扩大。M. alternatus 种群的爆发与松萎病的流行一起发生，因为这种昆虫在最近被该疾病杀死的寄主树上繁殖。我们测量了四年中成虫的一些传播和生活史特征，以确定与爆发相关的甲虫野外种群的飞行能力和生活史的变化。被监测的人群表现出爆发和随后的崩溃。最大平均体重，暴发年份后翅面积最大，翼载荷最小，产卵前期最短。相比之下，爆发前（潜伏）和爆发年份之间的卵巢数量没有差异。最大的平均后翼面积和最小的翼载荷表明可能会导致更好的飞行性能。正如其他研究表明的那样，成年体重与飞行性能和产卵率呈正相关。此外，缩短的预产卵期导致高繁殖率。因此，暴发人群中的成年人是“超级传播者”，因为他们可能具有增强的飞行能力和繁殖能力。这表明 M. alternatus 种群在种群爆发时提高了 B.