Ecological and genetic mechanisms for evolution of aposematic and cryptic coloration

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K16230
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Kochi University
• Principal Investigator: Suzuki Noriyuki 高知大学, 教育研究部総合科学系生命環境医学部門, 准教授 (00724965)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 捕食回避 / 色彩多型

Outline of Final Research Achievements

In this study, we examined ecological and genetic factors affecting elytra color patterns of a ladybird Harmonia yedoensis, which exhibits both aposematic and cryptic patterns within the species. We took photographs of the elytra of these samples under standard lighting condition and measured the number and area of black dot on the elytra. Moreover, we quantified elytra coloration by using color vision model. We found that these morphological traits were different among the islands and that considerable variation was maintained even within the same populations. Particularly, we detected some individuals with small dots and dull coloration from a few remote islands in Okinawa. These results indicate that in H. yedoensis, both aposematic and cryptic individuals coexist in the same population. Therefore, it is suggested that evolution of aposematic coloration from cryptic coloration (or vice versa) would be more likely to occur than previously imagined.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

見て分かるように、地球上の生物の色彩や模様は多様である。しかし、どのような生態的要因によってこうした多様性が生まれたのか、解明されていないことが多い。本研究では、同じ種類であっても地域間や地域内で色彩と模様の多様性が生じているテントウムシを対象にして、変異のパターンを定量化し、比較した。こうした進化生態学的研究は、生物多様性の創出・維持メカニズムを理解する上で欠かせないものであり、生物多様性を保全あるいは活用していく上での重要な知見となりえる。