Bleuberry spanworm

Description. Young caterpillar larvae are about 1/8-inch long and dark gray to black with a series of white bands encircling the body.  Fully grown larvae are about 3/4-inch long and are yellowish-orange with rows of black spots that may look like continuous black strips running the length of the body. Spanworm larvae often appear on plants in large numbers at night.   During the day, many larvae find shelter in the litter at the base of the plants.
An easily recognizable characteristic of this larva is its “looping” walk.  Pupae, which are rarely seen, are found in the litter and are dark brown or black.
Adult spanworms are delicate, light gray moths.  They have a wingspan of about one-inch (Photo 2).  They are especially common in weedy areas or wind breaks and will fly readily when disturbed.
Life Cycle. The blueberry spanworm spends the winter as an egg in the litter near the base of blueberry plants.  Eggs may begin to hatch and larvae start feeding on developing buds as early as April and continue to feed on blueberry leaves, buds, and blossoms until late June or early July.  Fully grown larvae move into the litter, where they remain as pupae.  At this stage and time, they do not feed.  Moths begin to emerge in about two weeks.
Adults can first be seen in the field in early to mid-June.  Some moths may still be present until late July. Eggs laid by the moths do not hatch until the following spring.