夏威夷群島穴居性夜蛾之行為與拓殖的演化研究

Evolution of cave living in Hawaiian Schrankia (Lepidoptera: Noctuidae) with description of a remarkable new cave species

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Zoological Journal of the Linnean Society (209) 156: 114-139.

Mattew J. Medeiros, D. Davis, Francis G. Howarth and Rosmary Gillespie

影響生物演化出穴居性的行為的因素，在溫帶地區可能是氣候變遷，而在熱帶地區則推測為棲地的拓殖事件。這些生物可能在形態、生理以及行為表現上與非穴居性生物有所差異，例如體色素消失、眼部退化、翅膀退化、無飛行能力或是附肢延長等，而作用於其上的因子可能為天敵的減少、穩定的食物源、高濃度的二氧化碳或其他氣體、黑暗、相對較不平坦的地表以及不同的溼度環境狀態。這些共同而容易被測量定義的洞穴性質即提供生物學家了解穴居生物的趨同與平行適應的演化歷史，而重建某一穴居生物的親緣關係即成為探討此議題不可或缺的方法。

夏威夷群島所產的四叉群夜蛾Hypenodinae亞科Schrankia屬(註1)原產五種特有種，皆具有正常的翅發育與飛行能力。Medeiros等人在此文章中以生殖器結構為依據將其中四種作同物異名處理為另外一種最早發表的S. altivolans (Butler, 1880)，並描述分布於Hawaii與Maui兩島具有穴居性行為的一新種S. howarthi Davis & Medeiros，再來採用後者進行飛行能力測試，了解其在島內洞穴間或島嶼間之長距離擴散的可能性，最後在親緣關係重建上選用粒線體DNA之COI與COII，以及核DNA wingless基因片段進行重建，除夏威夷島上之兩種外，另加上大溪地產未描述種，與大洋區廣佈種、並被認為夏威夷類群近緣種的S. costaestrigalis(註2)，以及Hypena屬類群作為外群。

結果顯示:

• 晚近分化的兩個形態種在分子樹上未各自形成單系群: 此研究中，親緣樹上主要的S. altivolans樣本形成S. howarthi樣本主支系中最晚近分化的一個支系之一，作者認為近似的形態種間並不形成穩定的單系群並沒有什麼好訝異的，因為在快速或晚近分化的支系，同域雜交與不完全的支系分化(incomplete lineage sorting)皆可能影響粒線體DNA所建構樹形的此類結果。
  

• 外部形態的相似性並不一定等同於遺傳片段上的親緣關係: 雖然在生殖器結構檢視上S. altivolans與外群S. costaestrigalis相對S. howarthi較為相近，然而分子樹型中S. altivolans並未與此外群有近緣關係。

• 單一洞穴內不同深度與狀態下所採集的樣本，在親緣關係中並無分化上的順序: 研究原本預期單一洞穴內的樣本，會隨著洞穴中由光與理化因子所分段定義的棲地，而有由淺入深的親緣分化關聯與順序，也就是出現於愈深愈黑暗無光區的樣本應會在最晚近才分化並拓殖於該區。然而結果是單一洞穴不同深淺區的樣本其在親緣樹上是散亂分布的，也代表洞內擴散與基因交流的存在。
  

• 島內洞與洞間族群是有基因交流的: 分子樹上顯示同一洞穴中的S. howarthi並非形成單系群，也就是洞與洞間的族群間有往來。依據作者的觀察，雖然穴居性S. howarthi有些個體具翅退化、眼尺寸變小，而且將牠們置於陽光下有容易死亡的現象，然而夜晚的外部地表環境類似於洞穴而易於在地面爬行，也使得洞與洞間交流的推測由親緣關係得到佐證。

• 島間各洞穴族群在親緣樹上無單系性: 由於測試上淺穴居性個體仍然有部份具有飛行能力，故島嶼間遷徙使得族群基因交流，進而使各洞穴樣本不形成單系群得到解釋。

• 物種分化的時間並不一定等同於地質史: 分佈於Maui島的S. howarthi族群在親緣樹上是插入於整個Hawaii島的族群之中，也就是相對較晚分化的族群，然而夏威夷地史上Maui島較Hawaii島早形成，此結果並不如大多數夏威夷群島研究生物之拓殖與火山島形成順序相同。

本研究的材料也是一系列夏威夷穴居生物類群中唯一有不同島嶼間族群存在同樣退化表型(phenotype)者。作者陳述他們的研究無法呈現各穴居個體無飛行力的行為，的確由趨同演化所造成，主要原因是此行為在此材料上並非一個穩定的”特徵”，而作者也提出未來對於此材料的表型可塑性與發育實驗的期待。

註1.
Schrankia屬為廣泛分布於全北區、大洋洲的類群，據Holloway (1989)、Poole (1989)與此篇文章，全世界約有41種，據台灣鱗翅目誌記載台灣產一種Schrankia seinoi Inoue, 1979.

註2.
Schrankia costaestrigalis (JPMoths影像連結)為廣泛分布於全北區與大洋洲的物種，據 徐堉峰老師(2007)所執行之「太魯閣國家公園昆蟲群聚與功能之研究（二）」中附錄十一記載此物種，該計畫存證標本現暫存放於中山大學昆蟲系統分類研究室。

ABSTRACT

Although temperate cave-adapted fauna may evolve as a result of climatic change, tropical cave dwellers probably colonize caves through adaptive shifts to exploit new resources. The founding populations may have traits that make colonization of underground spaces even more likely. To investigate the process of cave adaptation and the number of times that flightlessness has evolved in a group of reportedly flightless Hawaiian cave moths, we tested the flight ability of 54 Schrankia individuals from seven caves on two islands. Several caves on one island were sampled because separate caves could have been colonized by underground connections after flightlessness hadalready evolved. A phylogeny based on approximately 1500 bp of mtDNA and nDNA showed that Schrankia howarthi sp. nov. invaded caves on two islands, Maui and Hawaii. Cave-adapted adults are not consistently flightless but instead are polymorphic for flight ability. Although the new species appears well suited to underground living, some individuals were found living above ground as well. These individuals, which are capable of flight, suggest that this normally cave-limited species is able to colonize other, geographically separated caves via above-ground dispersal. This is the first example of an apparently cave-adapted species that occurs in caves ontwo separate Hawaiian islands. A revision of the other Hawaiian Schrankia is presented, revealing that Schrankia simplex, Schrankia oxygramma, Schrankia sarothrura, and Schrankia arrhecta are all junior synonyms of Schrankia altivolans.

[TaiBNET名錄修訂] 秋翠夜蛾之學名訂正與相關問題

文獻來源: Yanagita Y. 2009. Diphtherocome autumnalis (Chang) (Noctuidae) collected in Okinawa-jima and Amami-oshima Islands. Japan Heterocerists Journal 151: 13-15.

秋翠夜蛾為已故的張保信老師於1991年所描述的物種, 原本使用的學名組合為Daseochaeta autumnalis, 而此學名組合也為杉 繁郎於1992年的台灣鱗翅目昆蟲誌所沿用. 然而Hrebley等人於1998年研究西藏蛾類時認為autumnalis應改隸於Diphtherocome屬, 並置於Acronictinae亞科, 雖然Hrebley等人的分類處理完全未有任何的解釋, 但這樣的處理已經為Hrebley & Ronkay (1999), Hrebley & Kononenko (1999)以及傅建明與左漢榮所著鞍馬山的蛾(第一冊)所引用. 日本橫濱市的蛾類研究者柳田慶浩(Yanagita Yoshihiro)於2009年確認Diptherocome autumnalis亦分布於日本的沖繩本島與奄美大島, 並由吉野櫻上飼養出幼蟲. 柳田氏認為將autumnalis轉移至Diptherocome的合理性仍有待進一步的研究, 此外根據他所發現的幼蟲形態, autumnalis應該不屬於Acronictinae, 而比較可能屬於廣義的冬夜蛾亞科(Cuculliinae)或是近年重新定義的Psaphidinae. 目前TaiBNET上之秋翠夜蛾學名仍以原始組合呈現.

圖片連結: 林業試驗所昆蟲數位典藏計畫上傳至聯合目錄之秋翠夜蛾藏品

蝶類食性範圍是否可算是演化可塑性促進種化的範例?

Butterfly host plant range: an example of plasticity as a promoter of speciation?

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Evolutionary Ecology (2009) 23: 137-146

Sören Nylin¹ and Niklas Janz¹

Mary Jane West-Eberhard 曾主張可塑性可能是促進演化發生和多樣化的首要條件。在本文中，作者以蛺蝶為例子探討植食性昆蟲透過此過程演化的可能性。作者討論寄主植物與可塑性之間相連的方式，並呈現作者對於 West-Eberhard 的腳本如何可能導致由寄主利用所驅動的種化之闡釋。作者也在本文中回顧一些植物利用的多樣性促使植食性昆蟲多樣化之實例，最終討論這是否暗示了一個由可塑性驅動種化的角色。作者找到一個作者的理論(植食性昆蟲多樣化是由寄主範圍波動驅使)與作者對West-Eberhard的理論所作最有效率的解釋，兩者之間緊密的概念連結。一個主要未解決的議題是寄主植物範圍廣泛的程度是由於適應可塑性伴隨著為利用不同植物設計的遺傳機制的專用模組。

Abstract
Mary Jane West-Eberhard has suggested that plasticity may be of primary importance in promoting evolutionary innovation and diversification. Here, we explore the possibility that the diversification of phytophagous insects may have occurred through such a process, using examples from nymphalid butterflies. We discuss the ways in which host plant range is connected to plasticity and present our interpretation of how West-Eberhard’s scenario may result in speciation driven by plasticity in host utilization. We then review some of the evidence that diversity of plant utilization has driven the diversification of phytophagous insects and finally discuss whether this suggests a role for plasticity-driven speciation. We find a close conceptual connection between our theory that the diversification of phytophagous insects has been driven by oscillations in host range, and our personal interpretation of the most efficient way in which West-Eberhard’s theory could account for plasticity-driven speciation. A major unresolved issue is the extent to which a wide host plant range is due to adaptive plasticity with dedicated modules of genetic machinery for utilizing different plants.

植食性昆蟲切斷植物分泌管道的行為是否促進寄主範圍擴張?

Do canal-cutting behaviours facilitate host-range expansion by insect herbivores?

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Biological Journal of the Linnean Society, 2009, 96, 715–731.
DAVID E. DUSSOURD*

根據共演化理論中物種數逐漸增加之輻射演化模型，能克服植物防禦能力的植食性昆蟲可進入一個新的適應區域(adaptation zone)並因此在演化上得到較高的物種多樣性。目前關於植食者如何對植物防禦產生逆適應可能導致的種化所知甚少。根據蛺蝶的研究結果推測食性的擴張可能是關鍵的一步。本文檢測能以切斷管道 (canal -cutting)方法撤消植物防禦的食葉性昆蟲是否通常有比較廣的食性範圍。作者從文獻中鑑定出92種會切斷管道的昆蟲(canal cutters)，其中包括8種新的切斷通道者。已知寄主範圍的 canal cutters 中只有27%取食跨越多個科的寄主植物，此比例接近或低於整體植食性昆蟲中評估為廣食性者的比例。至多只有5種 canal cutters 專一性地取食具有分泌管的植物。廣食者數量不高有一部份可歸因於具有分泌管道的植物在親緣關係上距離相當遙遠，以及其對應之化學物質的特殊性。許多canal-cutting 物種對於從寄主植物的化學物質獲得防禦能力的倚賴，也會偏好種化發生。

Abstract
According to the escalation–radiation model of co-evolution, insect herbivores that acquire the ability to circumvent a plant defence enter a new adaptive zone and increase in species. How herbivore counter-adaptations to plant defences might lead to speciation is poorly understood. Studies of nymphalid butterflies suggest that the evolution of a broadened host range may be a critical step. This paper examines if leaf-feeding insects capable of deactivating defensive plant canals with canal cutting often have broad host ranges. A total of 94 species of canal-cutting insects were identified from the literature, including eight new canal cutters described in this paper. Only 27% of canal cutters with known host ranges are generalists that feed on plants in multiple families. The proportion of generalist canal cutters is similar or lower than estimates of generalists among phytophagous insects overall. Only five species, at most, of the canal-cutting generalists feed exclusively on plants with secretory canals. The paucity of generalists can be attributed in part to the considerable taxonomic distance separating canal-bearing plant families and to their corresponding chemical distinctiveness. The dependence of many canal-cutting species on host chemicals for defence would also favour specialization.

起源自安地斯山之透翅蛺蝶的物種多樣化格局

Photo by Pia's birdseye view

Out of the Andes: patterns of diversification in clearwing butterflies

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Molecular Ecology (2009) 18, 1716–1729

M. ELIAS,*†‡ M. JORON,†§ K. WILLMOTT,¶ K. L . SILVA-BRANDÃO,**,†† V. KAISER,† C. F. ARIAS,‡‡ L. M. GOMEZ PIÑEREZ,§§ S . URIBE,§§ A. V. Z. BROWER,¶¶ A. V. L. FREITAS** and C . D. JIGGINS‡

安地斯山的熱帶森林擁有全球生物多樣性的高峰，其令人矚目的地理特色似乎可提供促進產生生物多樣性的機會，如地理割據與生態上的種化。然而，對於占生物多樣性最多比例的昆蟲，這些山脈所扮演的角色仍很少被使用親緣關係方法進行研究。作者在本文中探討安地斯山在新熱帶區高多樣性的昆蟲- 蛉蛺蝶亞科(the clearwing butterflies）演化上扮演的角色。作者使用定年的種級親緣關係去評估發生種化的年代以及推測兩個多樣化的屬的祖先分布海拔範圍。結果顯示兩個屬可能都起源自第三紀中新世中期的安地斯山中海拔地區，與對脊椎動物發表的研究成果大多起源自低海拔相反。儘管作者偵測到由上新世-中新世之間安地斯山脈隆起所造成的割據種化訊號，大多數的姊妹種都是鄰域分布且沒有明顯的地理屏障。結合整體上趨緩的種化速率，此結果推測生態上的種化與適應性輻射所扮演的角色比單純的地理割據更為重要。

Abstract
Global biodiversity peaks in the tropical forests of the Andes, a striking geological feature that has likely been instrumental in generating biodiversity by providing opportunities for both vicariant and ecological speciation. However, the role of these mountains in the diversification of insects, which dominate biodiversity, has been poorly explored using phylogenetic methods. Here we study the role of the Andes in the evolution of a diverse Neotropical insect group, the clearwing butterflies. We used dated species-level phylogenies to investigate the time course of speciation and to infer ancestral elevation ranges for two diverse genera. We show that both genera likely originated at middle elevations in the Andes in the Middle Miocene, contrasting with most published results in vertebrates that point to a lowland origin. Although we detected a signature of vicariance caused by the uplift of the Andes at the Miocene–Pliocene boundary, most sister species were parapatric without any obvious vicariant barrier. Combined with an overall decelerating speciation rate, these results suggest an important role for ecological speciation and adaptive radiation, rather than simple vicariance.

夏季型與遷徙型帝王蝶的行為與分子上差異之解釋

Monarch butterflies. (Credit: iStockphoto/Paul Tessier)

Defining behavioral and molecular differences between summer and migratory monarch butterflies

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Haisun Zhu , Robert J Gegear , Amy Casselman , Sriramana Kanginakudru and Steven M Reppert

BMC Biology 2009, 7:14

東部的北美帝王蝶在秋季會進行相當長距離的遷徙。與春夏季蝴蝶比較，秋季的遷徙者的青春激素是有缺陷的，因而導致生殖停滯與延長壽命的現象。遷徙者也使用時間補償式的太陽羅盤幫助他們導航前往墨西哥的（西）南方向。此領域的中心議題是定義出青春激素的地位與飛行導向之間的關係、夏季帝王蝶和秋季遷徙者之間的關鍵特徵，以及與行為狀態相關的分子。

在此研究中，作者發現對秋季遷徙者增加青春激素活性會促進如夏季一般的生殖發育，但是不會改變方向性的飛行行為或時間補償的導航。 相反的，有生殖能力的夏季個體皆無法表現出方向性飛行或是導航的行為。作者使用9417 unique cDNA進行微陣列資料分析以定義與行為狀態相關的分子，基因表現數據顯示有一系列40個基因在腦中對個體遷徙的導航飛行行為有不同的表現、且與青春激素的活性無關，從而在分子層次上區分秋季與夏季的個體。這些具差異調節的複雜基因包括時鐘基因vrille和酪胺酸β水解脢。此外這些基因中有37.5%是尚未被註解的，作者鑑定了腦中的23個與青春激素有關、可區別帝王蝶是否具生殖能力的基因；也發現涉及長壽、脂肪酸代謝與免疫力的基因在無生殖能力的遷徙者（青春激素有缺陷）中有被促進的現象。

本研究成果連結了遷徙者和夏季蝴蝶之行為與腦中基因表現數據，且顯示出基因功能的季節性改變有助於定義遷徙狀態。

全球大弄蝶亞科之分類檢討

文獻來源: Chiba. H. 2009. A revision of the subfamily Coeliadinae (Lepidoptera: Hesperiidae). Bulletin of Kitakyushu Museum of Natural History, Series A 7: 1-102.

一本千呼萬喚才問世的一篇文章, 原始版本為千葉秀幸博士於1995年獲得夏威夷大學博士學位時的博士論文. 其中與台灣產分類群相關的觀點包含: (1) 台灣產尖翅絨弄蝶被視為原名亞種Hasora chromus chromus, 而非H. c. inermis; (2) 大綠弄蝶台灣亞種formosanus被處理為日本亞種的同物異名, 因此台灣產族群之有效學名成為Choaspes benjaminii japonicus, 此分類處理為新同物異名; (3) 台灣產褐翅綠弄蝶(chrysopterus)被視為原名亞種的同物異名, 因此其有效學名成為Choaspes xanthopogon xanthopogon.

Abstract
The subfamily Coeliadinae of the family Hesperiidae is reviewed. The group is classifi ed into 9 genera, 78 species, and 202 subspecies, in which a new species and 4 new subspecies are described. Four of the species previously classified in the genus Coeliades have been transferred to the genus Pyrrhiades. Keys to the genera and species, general generic characters, distribution pattern, synonymic lists, type information, and geographic distribution are given. Brief description and diagnostic characters are provided for each species and subspecies. In addition, their early stages and bionomics are also shown where known. Nearly all of the species and subspecies referred to are illustrated.