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
Brachycaudus cardui Brachycaudus cardui Brachycaudus cardui is a species of aphid, commonly known as the thistle aphid or the plum-thistle aphid. It infests trees in the genus "Prunus" in the spring and autumn, and mostly plants in the aster family in the summer. The viviparous wingless females of "B. cardui" have an oval or pear-shaped body and grow to a length of from . The colour may be green, yellowish, reddish or brown. The abdomen has a dark, shining patch on the dorsal surface, a fact which distinguishes this species from the otherwise similar plum leaf curl aphid ("Brachycaudus helichrysi"). Nymphs often