Cabbage Whites

Looking across our Littleton, Colorado, farm yesterday afternoon, a dozen or more cabbage whites fluttered amidst the greening landscape.  Generally the first butterflies to appear each spring and among the last to be seen in autumn, these small butterflies may be observed as early as February if warm spells envelop the Front Range.

Cabbage whites are off-white to pale yellow in color and bear black spots on their wings; females have two spots while males have one.  Emerging from cocoons in spring, the adults soon mate and females lay eggs on plants of the mustard family (including wild mustard, cabbage and radishes); the eggs hatch to release voracious caterpillars which later pupate to yield the next generation of adults.  In addition to their parenthood role, adults feed on nectar and pollinate a wide variety of wildflowers.

Natives of the Old World (Eurasia and Africa), cabbage whites were introduced in Quebec, Canada, in the late 19th Century and have since spread across most of North America, becoming one of our most abundant butterflies.  Their long period of activity (February to November in some years) and the abundance of their food crops account for their rapid dispersal across the Continent despite predation by bats, toads and a host of avian insectivores/omnivores (especially jays, bluebirds, mockingbirds and house sparrows).