The sight of small to medium-sized white butterflies fluttering is a common experience in many parts of the world. These insects signal the arrival of warmer weather and active growing seasons. While various species of white butterflies exist, one particular type, the Cabbage White, overwhelmingly dominates the temperate environments of North America, Europe, Asia, and Australia.
Identifying the Most Common White Butterflies
The small white butterfly most people encounter is the Cabbage White, scientifically known as Pieris rapae. This species is small to medium in size, with a wingspan ranging from 1.25 to 1.875 inches. The wings are a pale yellowish-white or creamy color, often featuring a charcoal or black patch on the forewing tips.
The Cabbage White is identified by the pattern of black spots on the upper side of its forewings. Females possess two distinct black spots, while males have only one. When resting, the underside of the wings often appears a uniform yellowish-green or gray-green, which helps the insect blend with foliage. The species is widespread across North America, having been accidentally introduced in the 1860s, making it one of the most common butterflies observed today.
Life Cycle and Host Plants
The butterfly’s life cycle proceeds through four stages: egg, larva, pupa, and adult. The female lays her eggs singly on the underside of host plant leaves. These tiny, yellowish, vase-shaped eggs have vertical ridges and hatch into the larval stage after about one week.
The caterpillar, often called the imported cabbageworm, is green with a thin yellow stripe running down its back. This larval stage is the primary source of garden damage, as the caterpillar is a voracious feeder that grows rapidly over two to three weeks. The host plants are in the mustard family (Brassicaceae), including cultivated vegetables like cabbage, broccoli, cauliflower, kale, and Brussels sprouts.
Once fully grown, the larva pupates, attaching itself to the host plant or a nearby sheltered area. The chrysalis is typically speckled green or tan, allowing it to camouflage. The adult butterfly emerges one to two weeks later, ready to mate and begin the cycle anew. They often produce three to five overlapping generations per year in temperate regions. This rapid reproductive rate, combined with the availability of human-cultivated host plants, explains why the Cabbage White is so common and can be found from early spring until the late fall.
Managing Garden Presence
Since the Cabbage White caterpillar can cause significant damage by chewing holes in leaves and boring into the centers of plants, gardeners often seek methods for control. One effective preventative measure is the use of physical barriers, such as fine-mesh netting or floating row covers. These barriers prevent the adult female from landing and laying eggs on susceptible plants and should be installed before the first adult butterflies appear in the spring.
Gardeners can also implement manual control by regularly inspecting the undersides of leaves for the solitary, cream-colored eggs and scraping them off. Manual removal of the small, green caterpillars is also an option, particularly when populations are small. Some gardeners use companion planting by scattering their brassica crops among other plants or by planting strongly scented herbs like dill or mint, which may help deter the egg-laying butterflies.