Vanessa cardui of the same species, he begins pursuit of her. If the foreign butterfly is a male, the original male will give chase, flying vertically for a few feet before returning to his perch. "V. cardui" establishes territories within areas sheltered by hedgerows. "Vanessa cardui" tend to inhabit sunny, brightly lit, open environments and are often attracted to open areas of flowers and clovers. Adults spend time in small depressions in the ground on overcast days. Larvae feed on Asteraceae species, including "Cirsium", "Carduus", "Centaurea", "Arctium", "Onopordum", "Helianthus", and "Artemisia". The painted lady uses over 300 recorded host plants according to
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