Vanessa cardui painted lady's migration pattern in northern Europe apparently does not follow a strict northwest heading. The range of headings suggests that migrating butterflies may adjust their migration patterns in response to local topographical features and weather, such as strong wind patterns. Laboratory-raised autumn-generation painted lady butterflies were able to distinguish a southern orientation for a return migration path. According to the same laboratory-based study, when butterflies were isolated from the sun, they were unable to orient themselves in a specific direction, opposed to those that did have access to the sun. This suggests that "V. cardui" requires a direct view
Urophora cardui arvense", during the host's growing season. After hatching, the larvae burrow into the stem of the plant and form a gall (or swelling). During maturing, the larva will be 98% of its full body weight, and appear as an adult. The larvae pupate in early spring for 24 to 35 days, and appear reddish brown, but are still inside the gall. The fly goes through a tunnel formed in the gall during June to October. Urophora cardui Urophora cardui or the Canada thistle gall fly is a fruit fly which, contrary to its common name, is indigenous to Central Europe