Japanese pine sawyer, Monochamus alternatus, is the main pest that mediates pine wilt nematode, Bursaphelenchus xylophilus, that causes serious damage to pine forests. In this study, we studied the strategy to control M. alternatus using entomopathogenic fungi. The fungi were collected from soil by an insect-baiting method and two fungal isolates (Metarhizium anisopliae JEF-197 and JEF-279) showed high virulence against M. alternatus. The Metarhizium isolates were evaluated for insecticidal activity against M. alternatus by spray treatment on live pine trees and wintering trees, and the M. anisopliae JEF-197 showed high insecticidal activity. In addition, the interaction of fungi and M. alternatus were analyzed by RNA-seq. This result can contribute to the development of insect control agents using entomopathogenic fungi.

Cuticular hydrocarbons (CHCs) of the pine sawyer (Monochamus saltuarius), Japanese pine sawyer (M. alternatus) and oak longicorn beetle (Moechotypa diphysis) were analyzed by GC, GC-MS and compared. Monochamus beetles are typical vectors of pine wilt disease but Moechotypa diphysis, which belongs to the same family, is not. They possess different CHCs in carbon number: 23-25 in M. saltuarius, 25-32 in M. alternatus, and 23-29 in M. diphysis. In comparison to inter-species, these three species of adult beetles have different numbers and chains of constituents of CHCs. In comparison between male and female in intra-species, the quantities of CHCs show the difference but constituents are not. Major constituent of M. saltuarius were analyzed as n-pentacosane ＞ n-nonacosane ＞ n-heptacosane, those of M. alternatus were n-nonacosene ＞ n-pentacosane ＞ n-nonacosane, and those of M. diphysis were n-heptacosane ＞ 13-methylheptacosane ＞ 3-methylheptacosane. From the body surface, most saturated carbohydrates of 3 species beetles are composed of n-alkane (40.2 - 65.7%) and followed by olefines ＞ monomethylalkanes that one or two double bonds in M. saltuarius and M. alternatus. Otherwise, M. diphysis have the difference in order of monomethylalkanes > olefins.