Intra- and Interspecific Variations in the Balance between Ant and Non-Ant Defenses in Macaranga

Japan Science and Technology Corporation京都大学名古屋大学Proceedings : IUFRO Kanazawa 2003 "Forest Insect Population Dynamics and Host Influences"., Scedule:14－19 September 2003, Vemue: Kanazawa Citymonde Hotel, Kanazawa, Japan, Joint metting of IUFRO working groups : 7.01.02 Tree resistance to Insects | 7.03.06 Integrated management of forset defoloating insects | 7.03.07 Population dynamics of forest insects, Sponsored by: IUFRO-J | Ishikawa Prefecture | Kanazawa City | 21st-COE Program of Kanazawa University, Editors: Kamata, Naoto | Liebhold, Nadrew M. | Quiring, Dan T. | Clancy, Karen M

ボルネオ ネッタイ ウリン ニ ミラレル オオバギゾク ニ オケル ヒショク ボウエイ センリャク ノ シュカン ヒカク

京都大学0048新制・課程博士博士(理学)甲第10012号理博第2673号新制||理||1361(附属図書館)UT51-2003-H433京都大学大学院理学研究科生物科学専攻(主査)教授 北山 兼弘, 教授 高林 純示, 助教授 湯本 貴和学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Correlation between the leaf turnover rate and anti-herbivore defence strategy (balance between ant and non-ant defences) amongst ten species of Macaranga (Euphorbiaceae)

We measured variation in the intensities of ant and non-ant anti-herbivore defences amongst ten Macaranga species in Sarawak, Malaysia. Intensities of non-ant defences were estimated by measuring effects of fresh leaves (provided as food) of these Macaranga species on survival of common cutworm larvae [Spodoptera litura (Fabricius), Lepidoptera: Noctuidae]. Intensities of ant defences were estimated by measuring ant aggressiveness in the presence of artificial damage inflicted on plants. As part of our examination of non-ant defences, we measured leaf toughness (punch strength, by penetrometry), and the contents of total phenols and condensed tannin. We demonstrated interspecific variation in intensities of both ant and non-ant defences amongst ten Macaranga species and showed that the rank order of ant defence intensity was negatively correlated with the intensity of non-ant defence. We also found that the balance between ant and non-ant defence intensity was correlated with the rates of leaf turnover and shoot growth. Species investing more in ant defence tended to have higher leaf turnover rates. Macaranga species that occur preferentially in shadier microhabitats had lower leaf turnover rates, suggesting that non-ant defences are more cost-effective in more shade-tolerant species. Our results also suggest that the total intensity of non-ant defences is positively correlated with both leaf toughness and total phenol content