The eggs hatched in about a week, but by September all traces of the creatures had disappeared. It turned out that the caterpillars would select dried wood or grass upon which to pupate. They would spend the winter as chrysalises and turn into butterflies the following April to June. Tsai would have to wait until the next year for that to happen.
蝶卵約一星期孵化，到了 9 月卻又不見蹤跡，原來幼蟲會選擇在樹下的枯木或枯草堆化蛹，然後靜靜過冬，直到隔年 4-6 月間才化蝶，就這樣，錯身而過，又得等一年。