Adult butterflies in this family are nearly all white or yellow, which is where they get their name. Their wings may have a few dark spots, or a dark edge, but they don't have many stripes or spots. They are medium-sized butterflies, with all six legs fully developed. In some species the color of adults is affected by the temperature when they pupated. Cooler temperatures usually produce darker colors.
Some species of Whites feed on plants in the mustard family that have toxic chemicals for protection. The caterpillars store the toxins in their body to discourage predators from eating them. Some other species of Whites may be mimicking the toxic ones by having similar wing colors and patterns.
The caterpillars in this group are mostly green or yellow and cylinder-shaped, and are covered with fine hairs or little black bumps.
There are over 1,100 species in this family, and they are found all over the world. There are 58 species in the U.S., and we have 17 different species in Michigan.
These butterfly species can be found in open areas wherever their food plants occur. Some species live in the Arctic tundra, others in tropical jungle. They are most common in places with lots of plant growth, but some feed on desert plants, and some in high rocky mountains. They feed on leafy weeds and herbs and vegetables, not trees, so they are most common in meadows and open areas, not forests.
Like all butterflies, these have complete metamorphosis. The caterpillars that hatch from the eggs eat and grow fast. They do not make a coccoon, but do attach themselves to plants with silk threads. Species in cold climates hibernate as caterpillars or pupae, and may have more than one generation over the summer.
Most only live for about a year or less, but some cold-climate species may live for two. These animals only live for a short time (a few days or weeks) as adults, they spend most of their lives in the immature stages. Some species can complete more than one generation a year, so individuals are only living for a few months.
Caterpillars in this species often feed at night and hide during the day. The adults are just the opposite, they are active only during the day. Some species migrate north in the spring or south in the fall to take advantage of good climates. They don't live long enough to make the return trip, only their offspring do.
These butterflies communicate mainly with their scent and their colors. Males attract mates with scent and display, and females leave a scent mark on plants where they have laid eggs.
Caterpillars of whites and sulfurs eat the leaves and flowers of plants. Most species only eat plants in the mustard family (including cabbage, broccoli, brussel sprouts, kale, and related vegetables) or in the bean family (including alfalfa and peas).
Adults sip flowers for nectar and mud for minerals and water.
Caterpillars hide, and have camouflage colors. A few species make nests of silk to hide in.
Adults fly during the day, and hide at night.
Some species collect toxic chemicals from their food plants.
They may have toxic chemicals from their food
Adults are pollinators, caterpillars can be important herbivores, limiting some plant populations.
One species of White, the Cabbage Butterfly (Pieris rapae) was accidentally brought to North America from Europe. It is a major pest on vegetables. Some native species eat alfalfa crops and other peas and beans.
Caterpillars of some species in this family eat plants that are weeds.
None of the White or Sulphur species in the U.S. are considered endangered.