The cabbage looper (Trichoplusia ni) is a lepidopteran insect
and an important pest of cole crops in Wisconsin. All cole
crops, including cabbage, broccoli, Brussels sprouts,
cauliflower, and rutabaga, are susceptible to attack by this
insect. In addition, cabbage loopers will also attack beets,
celery, lettuce, peas, potatoes, spinach and tomato. The cabbage
looper is named for the way in which the caterpillar stage of
the insect arches its body while moving. When fully grown, the
caterpillar has a greenish body that is 11∕2 inches long and
tapers near the head. There is a thin white line along each side
of the caterpillar and two white lines along its back. The
cabbage looper adult is greyish-brown, night-flying moth with a
wingspan of 11∕2 inches. The mottled brown forewings are marked
near the middle with a small, silver-white figure “8: or letter
“Y”. Symptoms and Effects: Cabbage looper larvae feed on cole
crop leaves between the large veins and midribs. Feeding occurs
primarily on the upper leaf surfac