They migrate 12,000 km annually, the longest known butterfly migration route
Move over, monarchs. The painted lady butterfly (Vanessa cardui) now boasts the farthest known butterfly migration.
Though found across the world, the orange-and-brown beauties that live in Southern Europe migrate into Africa each fall, crossing the Sahara on their journey (SN Online: 10/12/16). But what happened after was a mystery because the butterflies disappeared. Researchers hypothesized that the insects either remained in Africa or made a round-trip, but there was no evidence either way.
A new chemical analysis of butterfly wings suggests that the butterflies head back to Europe in the spring. The round-trip, which usually plays out over several generations, is an annual journey of 12,000 kilometers, about 2,000 more than