Alfalfa looper (Autographa californica), Lepidoptera

Alfalfa looper biology & life cycle

Adults are carried in each year on southern winds, although some overwitner as pupae in the soil. Adults appear all summer long due to two overlapping generations. Eggs are laid and the larvae hatch in June. Larvae feed for about 4 weeks and then pupate. The damage from larval feeding is characterized by clipping of flowers and small seed pods as well as ragged holes in the leaves. Total defoliation is possible, however canola plants can recover from light damage.

Identifying Alfalfa looper

Alfalfa looper: eggs

Eggs are circular, pale yellow and smaller than a pinhead.

Alfalfa looper: larvae

Alfalfa looper larvae are about 24 mm long, and have three pairs of legs on the thorax and three pair of prolegs on the abdomen. They are creamy white when newly hatched and become progressively greener as they develop. They have a paler green head and a light stripe down each side and two light stripes along the back. Fully grown larvae are about 25 mm long, and larvae move in a looping motion like an inchworm. Larvae clip flowers and small seed pods or chew ragged holes in leaves and on leaf margins.

Alfalfa looper: Pupae

Pupae are brown and about 20 mm long. They attached to the stems and are woolly in appearance.

Alfalfa looper: adult

Adult moths have a wingspan of about 40 mm, and near the center of each brownish-gray forewing is a silver figure-eight design. The lighter colored hind wings have dark margins.

Alfalfa looper: management

Few alfalfa loopers survive to the pupal stage due to a natural virus. Beat foliage and count number of larvae per square metre.