There are about 1,100 pierid species in the world, 58 of them in North America. Most of these species live in the tropics.
In our regions, most pierid caterpillars feed on plants in the bean or cabbage families.
Among the most common pierids in Quebec are the cabbage white, a white butterfly often seen in gardens, recognizable by the black spot on the forewings. This introduced species now occurs in large numbers almost everywhere in the province.
Another common species, the clouded sulphur, is found in many Quebec regions. It is a yellow butterfly that prefers open areas, meadows and bean fields.
Other pierids are rarer or live in highly specific habitats. For instance, the West Virginia white (Pieris virginiensis) is found only in maple-hickory stands in southern Quebec and Ontario, and in some US states. This type of rich, moist forest is where its host plant, two-leaved toothwort (Cardamine diphylla), grows. Unfortunately, the rich soil in maple-hickory stands means that they are often cleared for farmland. As a result this pierid was considered endangered in Ontario for many years, but has now been taken off the endangered list since enough stable populations have been observed in the wild.