White butterflies are a common and widespread sight across various global regions. Their delicate appearance graces gardens, fields, and open spaces, making them one of the most recognizable insects. They are found in numerous habitats.
Common White Butterflies
Among the most frequently encountered white butterflies are the Cabbage White (Pieris rapae) and the Large White (Pieris brassicae). The Cabbage White, also known as the Small White in Europe, is a small to medium-sized butterfly typically spanning 32 to 47 mm. Its creamy white wings usually feature black tips on the forewings, with females also displaying two black spots in the center of their forewings, while males have one. This species thrives in diverse environments, including meadows, forests, and particularly gardens and agricultural areas where its caterpillars feed on plants like cabbage.
The Large White, a close relative, is noticeably bigger, with an average wingspan of 5 to 7 cm. Its wings are also white with prominent black tips on the forewings, and females possess two distinct black spots on each forewing. These butterflies are common throughout Europe, North Africa, and Asia, inhabiting open areas such as vegetable gardens, parks, and agricultural fields.
How Butterflies Get Their White Color
The white coloration observed in many butterflies arises from two primary mechanisms: pigments and structural coloration. Pigments are chemical compounds that absorb specific wavelengths of light and reflect others, determining the colors we perceive. In white butterflies, the white color is largely due to pterin pigments, specifically leucopterin, which are deposited within nanoscale granules in their wing scales. Leucopterin absorbs ultraviolet light and reflects visible light, contributing to the white appearance.
Beyond pigments, structural coloration plays a role, especially in enhancing the brightness of the white. Butterfly wings are covered with microscopic scales, which are essentially modified hairs. These scales possess intricate microstructures that interact with light, scattering all wavelengths to produce a white appearance, similar to how snow appears white. This light scattering, combined with the presence of white pterin pigments, creates the brilliant white hues seen on their wings.
Distinguishing White Butterflies from White Moths
Differentiating white butterflies from white moths can be straightforward by observing a few key characteristics. One of the most reliable distinctions lies in their antennae: butterflies typically have thin antennae with club-shaped tips, whereas moths often have feathery or tapered antennae without a club. This difference is usually visible upon close inspection.
Another distinguishing feature is their resting wing position. Butterflies generally rest with their wings folded upright and together over their backs, while moths usually rest with their wings spread out flat or tent-like over their bodies. Activity patterns also offer a clue. Most butterflies are diurnal, active during the day, whereas the majority of moths are nocturnal and fly at night, often attracted to artificial lights.