Enchanting Masses of Little Yellow Butterflies Puddle on Country Roads

Have you ever wondered what those enchanting masses of little yellow butterflies that gather by the dozens or even hundreds around mud puddles on country roads are? These charming little fellows are the orange sulphur butterfly (Colias eurytheme), also known as the alfalfa butterfly, and their closely related cousin the clouded sulphur butterfly (Colias philodice).

These pleasant little yellow butterflies are common throughout most of North America. See a picture of these little guys and the subtle differences between the species, near the bottom of the page here. These are quite variable butterflies with colors ranging from yellow to white to orangish tints. A black wing border may be prominent or faded and small spots usually appear on the wings.

Frequently you will find both species gathered together on gravel roads. They gather in the wet soil around mud puddles - but not in the water - to sip nutrients from the wet soil. They use their coiled proboscis to obtain salts and minerals that they can't get from their nectar diet. This behavior is called puddling and gives you a wonderful chance for observing and photographing the congregrations of little yellow butterflies.

The Colias species of butterflies develop from small green caterpillars with a white and pink stripe on each side. The caterpillars feed on alfalfa, clover and other legumes. Occasionally they can be found feasting on soybean leaves.

The butterflies emerge during hot summer days and gather in delightful fluttering clouds of yellow. They are abundant during summer and autumn in rural areas. When the alfalfa fields are cut they often migrate en masse to the city.

Although the butterflies can become pests in alfalfa fields, control of the caterpillars is not warranted as most of the time they do little economic damage. So enjoy the little yellow butterfly show while it lasts!

Sources:

http://www.ipm.iastate.edu/

http://butterfly.ucdavis.edu/