White butterflies flutter through gardens and fields, prompting questions about their identity. These are not a single species but a diverse group, primarily from the Pieridae family, often called “whites” or “sulphurs.” Their widespread presence frequently prompts questions about what they are, where they come from, and what role they play in the natural world.
Common Types of White Butterflies
Among the most frequently observed white butterflies in North America are the Cabbage White, the Great Southern White, and the Checkered White. The Cabbage White, also known as the Small White, is common in North American gardens and open areas, introduced from Europe around 1860. This small to medium-sized butterfly has a wingspan of 1.25 to 1.875 inches (3.2 to 4.8 cm). Its wings are typically white or pale yellowish-white with distinctive black markings.
The Great Southern White is a larger species, with a wingspan of 2.5 to 3.375 inches (6.3 to 8.6 cm). It is primarily found along the southern Atlantic and Gulf coasts of the United States, extending through tropical America. Males are white with a black zigzag pattern along the outer edge of their forewings. Females vary by season, sometimes appearing dark or smoky gray.
The Checkered White is another widespread species, often found in open, disturbed areas like fields, roadsides, and urban environments. Its wingspan, similar to the Cabbage White, ranges from 1.25 to 2.5 inches (3.2 to 6.3 cm). This butterfly has white wings with varying black and gray checkered patterns, which are more pronounced on females.
Spotting the Differences
Distinguishing these white butterfly species involves observing wing markings, size, and flight patterns. The Cabbage White (Pieris rapae) males display one black spot on each forewing, while females have two spots and charcoal-colored tips. At rest, their undersides often appear yellowish-green or gray-green. They exhibit an erratic flight, darting quickly among plants.
The Great Southern White (Ascia monuste) has distinct wing patterns. Males feature a narrow, scalloped black border on their forewings, often with a zigzag appearance. Females are more variable; wet season females may have a smoky gray or brown appearance with more extensive black markings, while dry season females resemble males with heavier black patterns. A unique identifying feature for both sexes is their turquoise blue antennal clubs. Their flight is strong and direct.
The Checkered White (Pontia protodice) has noticeable black and gray checkered patterns, especially on the outer half of the forewings. Males have clearer white wings with black and gray spots, while females show more extensive and darker markings, sometimes appearing as a chain-like band along the hindwing margin. The underside of the female’s hindwing often displays yellow-brown to yellow-green markings along the veins. Its intricate wing patterns set it apart.
The Ecological Role of White Butterflies
White butterflies play an important role within ecosystems, despite their reputation among gardeners due to larval feeding habits. Adult white butterflies are active pollinators, visiting flowers to feed on nectar. This aids in the pollination of numerous plants, including wild species and cultivated crops like dandelions, red clover, and asters. Their foraging contributes to plant reproduction and biodiversity.
The caterpillars, or larvae, serve as a food source for various predators. Birds, spiders, and other insects, including parasitic wasps, feed on white butterfly larvae and pupae. This makes them part of the food web, transferring energy through the ecosystem. Many white butterfly species, particularly the Cabbage White, use plants from the mustard family as host plants for their caterpillars. This host-plant relationship forms a specific link within their habitat, affecting both butterfly populations and the plants.