Risk assessment of forest insects and their associated microorganisms before an outbreak: For a prospective provision

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03831
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Forest science
• Research Institution: Nagoya University
• Principal Investigator: KAJIMURA Hisashi 名古屋大学, 生命農学研究科, 准教授 (10283425)
• Co-Investigator(Kenkyū-buntansha): 神崎 菜摘 国立研究開発法人森林研究・整備機構, 森林総合研究所, 主任研究員 等 (70435585)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 樹木病害 / 森林昆虫 / 森林微生物

Outline of Final Research Achievements

Focusing on wood-boring insects, we have examined their habitation situation, reproductive patterns, etc. About two species of ambrosia beetles belonging to Euwallacea genus, we have clarified non-destructively location and structure of mycangia (fungal storage organ) by CT scanning. We have isolated and identified fungi and nematodes from the mycangia and insect bodies, host trees. We have inoculated these fungi and nematodes into host trees, and monitored wilting process of the trees to judge their pathogenicity. We have bred some kinds of organisms, which were collected or isolated, on various conditions, and proved their growth potential and interactions. Among study sites, we have found morphological and genetical differences of the organisms, and analyzed the data phylogeographically. Based on the above results, we have showed risky insects and their associated microorganisms, which should be marked from now on.

Free Research Field

森林保護学

Academic Significance and Societal Importance of the Research Achievements

昆虫と微生物が樹木を介してどのように共生関係を築いてきたか、という学術的命題に重要な示唆を与える。つまり、微生物の病原性と栄養価をめぐって昆虫類が進化させてきた繁殖戦略あるいは共生条件が明らかにできる。
森林生態系を脅かしている昆虫と菌類の共生関係に対して、その特性に関する科学的論拠を与える。そして、現在問題となっている被害だけでなく、将来の予知と予防にも究極的に有用であり、社会的要請に必ず応えることができる。潜在的なリスクをoutbreak前に先見的に評価しておく（先手を打つ）ことは、森林保護上きわめて大きな意義がある。