The role of the long frontal projections of lepidopteran larvae

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06079
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39050:Insect science-related
• Research Institution: Kindai University
• Principal Investigator: Kandori Ikuo 近畿大学, 農学部, 准教授 (00319659)
• Co-Investigator(Kenkyū-buntansha): 土原 和子 東北学院大学, 教養学部, 准教授 (10300823)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: イモムシ / 頭部突起 / 天敵からの防衛 / 食草探索補助 / ゴマダラチョウ / フタオチョウ / アオジャコウアゲハ / アサギマダラ

Outline of Final Research Achievements

Some lepidopteran larvae have long frontal projections, but their role is almost unknown. In this study, we made a "defense-from-natural-enemies" hypothesis about the role of hard projections, and tested the hypothesis using Polyura eudamippus larvae. When the larvae whose projections were artificially removed and the untreated larvae with their own projections were attacked the natural enemy paper wasps, the larvae with the projections had a significantly higher defense rate than the larvae without the projections. Therefore, the hypothesis was partially supported.
On the other hand, we made a "assisting-host-plant-search" hypothesis about the role of soft projections and tested the hypothesis using Parantica sita larvae. As a result, the larvae with projections found host-plants at a significantly higher rate than the larvae without projections. Therefore, the hypothesis was proved.

Free Research Field

昆虫生態学

Academic Significance and Societal Importance of the Research Achievements

チョウ目の幼虫がもつ頭部突起は大きく2グループに分けられる。1つは頭部から直接生える硬い突起であり、もう1つは頭部のすぐ後ろから生える柔らかい突起である。
前者について、私たちはすでにゴマダラチョウ幼虫を用いて「天敵からの防衛」仮説を実証したが、本研究におけるフタオチョウ幼虫の実験結果は、この仮説の普遍性を物語っている。一方後者について、私たちはすでにアオジャコウアゲハ幼虫を用いて「食草探索補助」仮説を実証したが、本研究におけるアサギマダラ幼虫の実験結果は、この仮説の普遍性を物語っている。これらの研究によって今後イモムシの多様で特異な形態の謎が一段と明らかになることが期待される。