Evaluation of the natural enemy effect by birds and predatory invertebrates in a paddy field ecosystem
| Project/Area Number |
15K07815
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Environmental agriculture(including landscape science)
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| Research Institution | Meijo University |
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Principal Investigator |
Hino Teruaki 名城大学, 農学部, 教授 (80212166)
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| Project Period (FY) |
2015-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000)
Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | フィプロニル系殺虫剤 / 天敵効果 / 総合的病害虫防除 / 野外操作実験 / カエル / クモ / ヨコバイ / ウンカ / 環境保全型農業 / フィブロニド系育苗箱用殺虫剤 / 総合的害虫管理 / フィブロニル系殺虫剤 / 間接効果 / トンボ / 野外実験 / 水田 |
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| Outline of Final Research Achievements |
Application of fipronil insecticide increased significantly the numbers of a paddy-rice pest insects, i.e., leaf- and plant-hoppers and then decreased the 500-grain weight of rice. This result is because the insecticide decreased the numbers of frogs and spiders which were natural enemies of the pests. The frog numbers depended on whether the tadpoles could mature before water-drawing after they were killed by insecticide when rice-planting, and the spider numbers depended on the number of its predators (i.e., frogs). Thus, the natural-enemy effect was exhibited by frogs in the frog-abundant year and by spiders in the opposite year. Therefore, this research showed that strong insecticides like fipronil is an adverse effect on insect pest control owing to killing natural enemies.
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| Academic Significance and Societal Importance of the Research Achievements |
フィプロニル系の殺虫剤は殺虫力が高いが、天敵生物まで殺してしまうために、害虫が増えて収量が減るという逆の効果が生じることが明らかになった。カエルについては、中干しの時期を調整することで殺虫剤の影響を緩和することが分かった。上位捕食者であるカエルが殺虫剤の影響を受けた場合には、下位捕食者であるクモによる天敵効果が発揮されることも分かった。これらの成果は、水田生態系における複雑な生物間相互作用について明らかにした学術的な意義だけではなく、天敵の効果を発揮させるためには殺虫力の高い殺虫剤は使用を控えるべきことを明らかにし、総合病害虫防除を進めていく上で応用的意義も大きい。
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Report
(5 results)
Research Products
(3 results)
