蝴蝶的一生     The Life History of Butterflies
蝴蝶是完全變態昆蟲，一生歷經卵、幼蟲、蛹、成蟲四個階段，每個階段的外型與習性各異其趣。以下以陽明山國家公園最具特色的青斑蝶（大絹斑蝶） Chestnut Tiger為例，介紹牠們變化多端的一生

Butterflies undergo complete metamorphosis through four stages in their life cycle: egg, larva, pupa, and adult.  Each
stage has its own distinct appearance and behavior.  The following introduces the ever-changing life journey of the Chestnut Tiger (Parantica sita), one of the most iconic butterflies in Yangmingshan National Park. 

 

卵     Egg 
青斑蝶（大絹斑蝶）的卵呈砲彈型，外表乳白色，上有方格狀花紋。雌蝶通常將卵產在幼蟲取食的寄主植物如台灣牛嬭菜的葉背。

 
The egg of the Chestnut Tiger is pale yellow and bullet-shaped with a reticulated pattern.  Females usually lay their eggs on the underside of the leaves of host plants, such as the Formosan condor vine (Marsdenia formosana). 

 

青斑蝶（大絹斑蝶）的卵

 

幼蟲     Larva 
蝴蝶幼蟲的唯一任務，就是不斷進食。進食長大後，必須蛻皮才能繼續成長，每蛻一次皮稱為一齡。青斑蝶（大絹斑蝶）的幼蟲有五個齡期，二齡後的幼蟲身上有多對肉棘，看起來狀似嚇人，其實只是虛張聲勢。不過牠身上的鮮豔色彩可不是唬人而已，牠會將寄主植物夾竹桃科的毒素留存在體內，讓天敵不敢捕食。

 
A larva's sole mission is to eat continuously.  As it grows, it must molt to enter the next instar.  The Chestnut Tiger has five instars.  From the second instar onward, the larva develops fleshy tentacles (scoli), looking intimidating but actually just bluffing.  However, its vibrant colors serve as a genuine warning (aposematic coloration).  The larva sequesters toxic secondary metabolites (cardenolides) from its host plants to deter predators. 

 

青斑蝶（大絹斑蝶）的終齡幼蟲

 

蛹     Pupa 
終齡幼蟲化蛹前會吐絲集結成絲墊，讓自己牢牢固定在枝葉上，安全渡過處於靜止狀態的漫長蛹期。青斑蝶（大絹斑蝶）的蛹在表皮硬化後會出現金屬光澤，有人認為這是警戒色，也有人認為這樣更容易融入環境。羽化之後，蛹殼便恢復透明。

 
Before pupating, the final-instar larva spins a silk pad, anchoring itself securely by its cremaster to a twig to safely pass the dormant pupal stage.  As the exoskeleton hardens, the pupa develops a striking metallic sheen.  Some consider this aposematic coloration, while others believe it helps the pupa camouflage in its environment.  After emergence, the empty pupal case becomes transparent. 

 

青斑蝶（大絹斑蝶）的蛹

 

成蟲     Adult 
經過十餘天的全身大改造，青斑蝶（大絹斑蝶）以完全不同的樣貌出現：以複眼探索世界，以虹吸式口器吸食花蜜，以雙翅飛翔、求偶、交配，完成這一生的重大使命。

 
After more than ten days of complete transformation, the Chestnut Tiger emerges in a totally different form.  It now explores the world with compound eyes, feeds on nectar with a siphoning proboscis, and flies with a new pair of wings to court and mate, fulfilling its ultimate life mission. 

 

青斑蝶（大絹斑蝶）的成蟲