But while a butterfly completes its life cycle through the egg, larval, pupal and adult stages in just over 30 days, fireflies need a year. This takes long-term nurturing and food preparation, consuming a great deal of effort, to produce a mere 20 or so days of glowing swarms. One can say that this is one of the more costly insects.
而同樣是經過卵、幼蟲、蛹、成蟲等 4 階段的完全變態過程，蝴蝶一代只需三十幾天，螢火蟲卻要一年，必須長時間照料、為牠準備食物，耗費大量心神，只為了換取約 20 天群聚飛舞的閃亮瞬間，可以說是代價最「昂貴」的昆蟲之一。