Vanessa cardui of the sky, implying the use of a solar compass to orient its migratory direction and maintain a straight flight path. "V. cardui" displays a unique system of continuous mating, throughout all seasons, including the winter. This may be attributed to its migratory patterns, thus significantly affecting its mating behavior. During European migrations, the butterflies immediately begin to mate and lay eggs upon arrival in the Mediterranean in the spring, starting in late May. In the United States, painted lady butterflies migrating towards the north experience poor mating conditions, and many butterflies have limited breeding capabilities. The "local adult generation"
Urophora cardui 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 from the United Kingdom east to near the Crimea, and from Sweden south to the Mediterranean. The Canada thistle gall fly has been introduced to North America from Europe to control the population of its host plant, Canada, or creeping thistle, which is an invasive, introduced weed in North America. The fly starts life as an egg, about one to thirty of them, laid on the stems of its host plant, the Canada thistle, "Cirsium