Because in the Fall they “Let It Go” and in the Spring they “turn over a new leaf”.
Interesting Fact:Azaleas/əˈzeɪliə/ are flowering shrubs in the genus Rhododendron, particularly the former sections Tsutsuji (evergreen) and Pentanthera (deciduous). Azaleas bloom in spring, their flowers often lasting several weeks. Shade tolerant, they prefer living near or under trees. They are part of the family Ericaceae.
Interesting Fact: Actually, butterflies do not eat at all. Well, at least not in the traditional sense. What do butterflies eat? Instead of eating, butterflies get their nurishment from drinking. They have a long narrow tube in their mouth called a proboscis that acts as a straw. They usually set on top of a flower and drink the nectar. To see a congregation of many kinds of butterflies together they feed on small puddles on the grouind or wet areas on leaves and plants. See the section below if you are interested in what Caterpillars eat. ( http://www.whatdobutterflieseat.info/ )