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.

The pine wilt disease that blocks the path for water and nutrition in pine trees is caused by the nematode, Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae). The nematode relies on the longhorn pine sawyer beetle Monochamus alternatus and Monochamus saltuaris (Coleoptera: Cerambycidae) as vectors. Recently, 2-(undecyloxy)ethanol was identified as a male-produced aggregation pheromone of Monochamus species. In this study, we investigated the effect of 2-(undecyloxy) ethanol along with host plant volatiles -pinene and ethanol on attracting M. alternatus at a pine forest in Pohang, Korea from May, 2014 to July, 2014. To sustain the volatility of 2-(undecyloxy)ethanol and host plant volatiles, a superabsorbent polymer based on polyacrylic acids and water were added to the pheromone mixture. A total of 46 M. alternatus were collected from two field bioassays. Our results indicate that 2-(undecyloxy)ethanol is effective in attracting M. alternatus in Korea. Our study suggests that the aggregation pheromone could be used for detection and population monitoring of the beetles as well as for the effective mass trapping in outbreak situations.

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.

This study was performed to investigate the emergence timing and daily emergence from the different tree species logs (Korean white pine, Pine, and Japanese larch) at Cheongwon, Chungcheongbuk-do from 2006 to 2008. Pine sawyer adults began to emerge on early May (2~10th day) and finished on mid-June (4~20th day) in the Korean white pine and pine logs. However, pine sawyer adults began to emerge on mid-May (13th day) and finished late May (27th day) in Japanese larch logs. Japanese larch logs shows shorter emergence timing of pine sawyer adult compare to those of other two tree species. Emergence timing shows no difference between males and females. Sex ratios of emerged adult in 2007 were 0.55 from Korean white pine, 0.46 from Pine, and 0.59 from Japanese larch, it shows no difference among tree species. Female and male adults emerged throughout 24 hrs, 22.8% of the total adults emerged from 12~14:00 (22.8%) and adults emerged lowest from 06~08:00. Of the adults emerged from the logs, 98.9% was univoltine and the rest was biennial which emerged next year.

Pine sawyer beetle, Monochamus saltuarius preferred the feed on fresh twig of Korean white pine trees (Pinus koraiensis) than one-year old and two-year twig. It means that the current twig is appropriate to increase the lifespan and reproduction of this insect. In a bioassay after fractionated the hexane layer from the water layer, the hexane layer did not show feeding response; however, the water layer was preferred in the order of fresh twig>one-year twig>two-year old twig. By HPLC analysis, we identified three kinds of sugar, namely, fructose, sucrose, glucose. The quantity of fructose was the highest in fresh twig followed by one-year and two-year old twig. In the preference test using each standard sample, the order was fructose>sucrose>glucose at 10, 30 μg/filterpaper, and fructose>sucrose >glucose at 50μg/filterpaper. From the above result, fructose plays an important role as a feeding stimulant for pine sawyer adult.