黃蝶寄主植物偏好性分析

Analysis of Eurema hecabe host-plant adaptation

邱秀婷

指導教授 ： 徐堉峰

國立臺灣師範大學/理學院/生物學系在職進修碩士班/碩士(2002年)

摘要

黃蝶（Eurema hecabe hecabe Linnaeus）廣泛分布於亞洲及澳洲等地，在台灣則為中低海拔常見蝶種。在台灣地區之幼蟲寄主植物依文獻之記錄包含三科20種，但利用範圍侷限。一科中僅有特定的屬種能被利用，而且食用某特定寄主的幼蟲常常不能接受其他幼蟲利用的寄主。
日人研究日本地區黃蝶依其緣毛形態分為黃色型及褐色型，此二型以不同的豆科植物為食，季節形態、季節適應、產卵偏好皆有差異，且雌蝶具有篩選同型雄蝶的能力，顯示分布於日本的黃蝶已有種分化跡象。台灣的黃蝶亦有黃色型及褐色型分布，但目前尚未有類似分析測試，不知是否有類似的分化現象。本研究以鼠李科桶鉤藤、大戟科紅仔珠、豆科蘇木亞科黃槐、蝶形花亞科田菁等不同科或不同亞科植物作為寄主植物，依幼蟲食性不同，將黃蝶分別稱為田菁型、黃槐型、紅仔珠型、桶鉤藤型等四型，測試各型黃蝶是否有形態差異、食性分化、產卵偏好，進而推論種分化是否已存在於目前被視為只有單一生物種的黃蝶中。
將黃蝶依幼生期體型、前翅長及生長速度分別經HSD分群，黃槐型與田菁型為同一群，桶鉤藤型與紅仔珠型為同一群。若利用主成分分析（PCA）歸群，結果為田菁型與黃槐型為同一群，桶鉤藤型與紅仔珠型同一群。若以成蝶形態差異比較，田菁型與黃槐型為同一群，桶鉤藤型與紅仔珠型為獨立二群。
寄主植物交換測試結果顯示，田菁型與黃槐型為同一群，桶鉤藤型與紅仔珠型為獨立兩群，且桶鉤藤型及紅仔珠型可能分別由田菁黃槐型演化而來。
產卵行為測試結果發現：無論以黃槐或田菁為寄主植物的雌蝶，產卵時均較偏好田菁，黃槐次之，雌蝶拒絕於桶鉤藤、紅仔珠產卵。桶鉤藤型雌蝶大多產在桶鉤藤植株，少數個體會產少量卵於黃槐，田菁及紅仔珠則被拒絕。此結果說明黃槐型與田菁型為同類群，桶鉤藤型獨立為一類群與黃槐型有關，紅仔珠型獨立為一類群。
綜合形態、發育、寄主植物交換測試及產卵偏好測試結果得知，分布於台灣的黃蝶有食性分化，田菁型與黃槐型為同型，紅仔珠型、桶鉤藤型則分別為不同群，且可能分別自食性為豆科的祖先演化而來。
黃蝶尚有許多寄主植物未作測試，是否有其他型存在，有待進一步測試。另外，這些型的親緣關係尚未明瞭，本研究可提供親緣關係分析的基礎，並在親緣關係釐清之後，供作黃蝶食性進化之參考。

關鍵字

黃蝶 ； 寄主植物偏好 ； 形態 ； 產卵偏好

並列摘要

Larval host-plants of Eurema hecabe Linnaeus in Taiwan include three families, twenty species according to literature. Only certain members of each family are utilized by the larva, which often does not accept alternative potential hosts.
In Japan, Eurema hecabe Linnaeus consists of two distinctive morphs. They differ in the fringe color of wings（brown or yellow）and other phenotypes. It has recently been found that sexual isolation exists in these two types. Both types（brown or yellow）of Eurema hecabe are also present in Taiwan. Whether there are isolation mechanisms occurred between them still remains to be confirmed.
The present study used Rhamnus formosana, Breynia officinalis, Cassia surattensis and Sesbania cannabiana as larval host-plants. According to larval hosts, four types of Eurema hecabe were recognized, namely, S. cannabiana type, C. surattensis type, B. officinalis type and R. formosana type, respectively. Some experiments were performed to test their morphological difference, larval performance and oviposition preference to infer whether isolation presents among these types.
Seperated by morph, growth rate and principal-components analysis（PCA）,C. surattensis type and S. cannabiana type are the same group. R. formosana type and B. officinalis type are the other group. Seperated by wing color pattern, C. surattensis type and S. cannabiana type are the same group,whereas R. formosana type and B. officinalis type represent different kinds of groups.
Seperated by host-plant adaptation and oviposition preference, C. surattensis type and S. cannabiana type maybe the same group. R. formosana type and B. officinalis type represents different kinds of groups. Besides, R. formosana type and B. officinalis type may have evolved from Fabaceae associated ancestors.
In conclusion, Eurema hecabe in Taiwan are divided into three distinctive groups, ie, C. surattensis type and S. cannabiana type as the same group, whereas R. formosana type and B. officinalis type each represents a distinctive group. R. formosana type and B. officinalis type may have evolved from the Fabaceae-feeding ancestors. Finally, C. surattensis type and S. cannabiana type probably represent the brown type, whereas R. formosana type the yellow type, and B. officinalis type a previously unrecognized group.
There are many host-plants of Eurema hecabe remained untested. Whether there is present any new host types needs further research. This study provides the first report to the analysis of relationship among host types of Eurema hecabe in Taiwan.

並列關鍵字

Eurema hecabe ； morph ； oviposition preference ； host-plant adaptation