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Alfalfa Butterfly

Colias eurytheme (aka Orange Sulphur)


This butterfly has a wingspan of 1-2 inches. It is distinguished from other sulphurs by its orange-yellow wings edged in black. The forewing often has prominent black spots, while the hindwing has a slightly deeper orange or yellow spot. The upperside of the male is yellow with orange overlay and yellow veins; the female is usually yellow or white with an irregular black border surrounding light spots.



Distribution and Habitat

One of the most common butterflies in North America, the alfalfa is found from southern Canada into central Mexico, except for the Florida peninsula. It is extremely adaptable to a variety of habitats, from woodlands to meadows to tundra and alpine summits.

Life Cycle

Adult alfalfa butterflies are most commonly seen from midsummer to autumn, when the plants on which their caterpillars feed are in full bloom. After emerging from their pupal stage, adult males will patrol their "neighborhoods" for receptive females. The reddish eggs are laid singly on top of the host plant leaves, and will hatch in 3-10 days. The alfalfa caterpillar can be distinguished by its velvety green body with a narrow, white stripe running down each side. The caterpillar may reach a length of about 15 inches before it enters the pupal stage. Some parts of the alfalfa's range may enjoy two or three flights of adult alfafas in a good year.



Alfalfa larvae feed on alfalfa, clover and legumes, while adults feed on nectar from a variety of flowers, including dandelions, milkweeds, goldenrods and astera.

Scientific Classification

phylum Arthropoda
class Insecta
order Lepidoptera
family Pieridae
genus & species Colias eurytheme

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The Robinson Library >> Insects >> Order Lepidoptera

This page was last updated on June 13, 2018.