Estimating the density of forest insect assemblages considering catch efficiency of traps using Bayesian modeling

2018 Fiscal Year Final Research Report

• Project/Area Number: 17H07347
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Forest science
• Research Institution: Forest Research and Management Organization
• Principal Investigator: Yamanaka Satoshi 国立研究開発法人森林研究・整備機構, 森林総合研究所, 研究員 (10804966)
• Project Period (FY): 2017-08-25 – 2019-03-31
• Keywords: 森林性昆虫 / トラップ / 捕獲効率

Outline of Final Research Achievements

I focused two survey methods for forest insects (pitfall trap and Malaise trap) and investigated the effect of environmental factors on catch efficiency of the traps. For pitfall trap, I investigated the relationship between the abundance of ground beetles caught per day and soil temperature using the reduction method. For Malaise trap, I investigated the relationship between the abundance of longhorn beetles and three factors (air temperature, wind speed, and canopy cover). I found that catch efficiency of pitfall traps was increased with the soil temperature for two of three ground beetle species and that for three of four longhorn beetle species, the abundance was affected by at least one environmental factor. These results suggest that the environmental factors could affect the trap efficiency and that it is essential to consider the changes in environmental factors and the difference in catch efficiency of traps among sites when investigating forest insects.

Free Research Field

森林生態系管理

Academic Significance and Societal Importance of the Research Achievements

森林昆虫は多様な種が含まれる分類群であり、様々な生態的機能を発揮することにより森林生態系の維持に重要な役割を担っている。このため森林生態系保全を検討するうえで、昆虫群集のモニタリングは重要である。一方、昆虫調査では、トラップの捕獲効率が周囲の物理環境によって変わりやすく、生息密度を明らかにできないという欠点が長年指摘されてきた。本研究では集中的な野外実験にて得られたデータから、物理環境が各種の捕獲効率に及ぼす影響を検証した。本研究の結果は、物理環境が異なる地域間で昆虫相を比較する際に考慮すべき環境要因の特定に繋がり、広い地域で昆虫モニタリングを効率的に実施するための知見を提供すると考えられる。