西藏翠蛺蝶種複合群之系統分類研究

Abstract

西藏翠蛺蝶種複合群(Euthalia thibetana complex)係蛺蝶科(Nymphalidae)翠蛺蝶屬(Euthalia)之中大型蝶種。此複合群的種間辨識主要以翅紋及交尾器特徵為主，但觀察發現其各種內的翅紋變異常高於種間，難以作為可靠的辨識特徵。因此本研究加入常用於親緣關係研究之粒線體COI、COII與核基因的Eflα之序列並輔助形態的資料，冀望獲得可辨識此群種間的可靠特徵。本研究共使用158個樣本，計有35個外群樣本及123個內群樣本，皆採集自台灣與中國大陸。不同組合的資料矩陣及分析方法皆將此複合群分為六個單系群。檢視各群之形態特徵與相關文獻，發現雄蝶交尾器結構中抱器(valva)末端的結構為穩定可靠的形態特徵。此複合群包括Koiwaya(1996)與Huang(2001)所分辨的六種：E. formosana、E. insulae、E. thibetana、E. alpherakyi、E. aristides、及E. undosa。而近年發表的新種E. yasuyakii、E. masumi應為E. undosa之同物異名，E. kameii為E. aristides之同物異名。E. undosa相對於其他五種，四川族群展現出極大的變異，造成種間辨識困難。此複合群不同地理族群間翅紋亦有變異，是否具有適應或生態上的意義值得探討。

Euthalia thibetana complex is a group of closely relative butterflies. Because the instraspecies wing pattern presents more variable than interspecies, it is often confused with its species determination. In this study, the purpose is to find out the reliable characters for identifying the species of this complex through comparing molecular (mithchondrial COI and COII genes and nuclear Eflα gene) and morphological datasets (wing pattern and genitalia). Total 158 nymphalids major form mainland China and Taiwan were sampled. Six monophyletic groups were recognized through inferring molecular phylogenies, and those groups were also supported by the structure of male genitalia. Therefore, the species, listed in the complex, are included E. formosana, E. insulae, E. thibetana, E. alpherakyi, E. aristides, and E. undosa. However, three newly described species, included E. kameii, E. yasuyakii, and E. masumi, are all synonyms of the regarding species. The main reason why the butterflies in this complex are so hard to recognize is because the wing pattern of E. undosa is too variable to distingulish with other five species.