Pieris rapae

Pieris rapae, the small white, is a small- to medium-sized butterfly species of the whites-and-yellows family Pieridae. It is also known as the small cabbage white and in New Zealand, simply as white butterfly. The names 'cabbage butterfly' and 'cabbage white' can also refer to the large white. The butterfly can be distinguished by the white color with small black dots on its wings. They are further distinguished by the smaller size and lack of the black band at the tip of their forewings. It is widespread and is believed to have originated in Europe or Asia. It is also found in North Africa and has been accidentally introduced to North America, Bermuda, Australia and New Zealand. The caterpillar of this species is seen as a pest for commercial agriculture. Often referred to as the 'imported cabbageworm' they are a serious pest to cabbage and other mustard family crops. In appearance it looks like a smaller version of the large white (Pieris brassicae). The upperside is creamy white with black tips on the forewings. Females also have two black spots in the center of the forewings. Its underwings are yellowish with black speckles. It is sometimes mistaken for a moth due to its plain appearance. The wingspan of adults is roughly 32–47 mm (1.3–1.9 in). The species has a natural range across Europe, Asia, and North Africa. It was accidentally introduced to Quebec, Canada around 1860 and spread rapidly throughout North America. The species has spread to all of North American life zones from Lower Austral/Lower Sonoran to Canada. Estimates show that a single female of this species might be the progenitor in a few generations of millions. It is absent or scarce in desert and semidesert regions (except for irrigated areas). It is not found north of Canadian life zone, nor on Channel Islands off the coast of southern California. By 1898, the small white had spread to Hawaii; by 1929, it had reached New Zealand and the area around Melbourne, Australia and found its way to Perth as early as 1943. Surprisingly, it does not seem to have made it to South America.