Alfalfa Caterpillar
Colias philodice eurytheme (Latr.)

PLANTS ATTACKED: General feeder on all legumes.

DESCRIPTION: Adult. The butterfly has a wing-spread of about 2 inches. Each wing is yellow, bordered by black. Yellow spots in this border distinguish the female from the male.

Larva.The full-grown larva is about 1 1/2 inches long. Its body is grass-green and usually has a fine white stripe on each side through which passes a red line.

LIFE HISTORY: This insect may spend the winter in the pupal stage on the plant; however, the larva may be found throughout the year in extreme southern regions of Texas. The female lays 200 or more eggs, which she deposits singly on the undersides of leaves. Eggs hatch into worms which are black at first but soon become green. The larva reaches maturity within about 2 weeks and changes to a pupa without spinning a cocoon. The pupa attaches itself to a plant stem by its narrow tail end and then throws a loop of silk about its body and over the stem by which it holds the head upright. It remains in the pupal stage for 5 to 7 days. There may be as many as seven generations a year.

DAMAGE: The larvae feed at first by eating small "shot-holes" in the leaves but eventually may consume all the leaves and may feed on the stems of alfalfa and other legume plants.