Vanessa cardui migrations take place at high altitude, which explains why these migrations are seldom witnessed. "V. cardui" is known for its distinct migratory behavior. In California, they are usually seen flying from north to northwest. These migrations appear to be partially initiated by heavy winter rains in the desert where rainfall controls the growth of larval food plants. Painted lady migration patterns are highly erratic and they do not migrate every year. Some evidence suggests that global climatic events, such as el Niño, may affect the migratory behavior of the painted lady butterflies, causing large-scale migrations. Based on experimental data, the
Tingis cardui or May, and sit on the basal leaves of their food crops. Some make dispersion flights to colonize new plants. Mating and oviposition lasts until July. The females drill their eggs individually on both sides of the leaves into the tissue of the food plant. The nymphs occur from June until September. Older nymphs are often located between the spines on the outside of the flower baskets or close to it. The adult animals of the new generation occur from late July or early August. Tingis cardui Tingis cardui is a Palearctic lacewing bug. The species is widespread in almost