Butterflies and moths have survived on earth for much longer than most people realize. The fossil record indicates that moths evolved about 400 million years ago. Through the processes of natural selection, diverse lineages branched out giving rise to the families and numerous species that occur today. Butterflies are part of one lineage that dates back to about 40 million years ago. They can usually be distinguished by the thickened tips on the ends of their antennae and daytime flight activity.
Most moths have thread-like or feathery antennae and fly at night.
When it comes to the numbers of species, moths have butterflies outnumbered by a factor of nearly 10 to 1. The museum's Lepidoptera collection is not large by museum standards, though there are more than 220,000 specimens. What may be lacking in numbers is more than made up for by the quality of the collection and the natural diversity represented. The collection contains examples of species from throughout the world and from the major family groups. There are butterflies and moths of once common species, that are now rare, and examples of naturally rare occurrences, like a six-winged butterfly and moth with three antennae.