Introduction

Soybean loopers are commonly found throughout the southern United States and in South and Central America. It feeds on many different cultivated crops including cotton, tobacco, tomato, peanut and sweet potatoes.

Cabbage loopers are found throughout the United States. It also feeds on a variety of host plants, which include cotton, beans, tomatoes, soybean and lettuce.

Both soybean and cabbage looper are normally controlled by a host of natural controls including predators, parasites and entomopathogens. These controls normally maintain the looper population below damaging levels. However, when the populations of these natural controls are reduced as they are with repeated insecticide applications, the looper population can explode and cause serious defoliation. In cotton, this most often occurs near the end of the season when defoliation is of little consequence. But, looper populations can reach treatment levels earlier when defoliation can seriously impact yield. So looper populations can not be ignored and must be scouted.

	Image courtesy of Dan Mott/Jack Bacheler: North Carolina
	Image courtesy of Dr. Ron Smith: Auburn University and University of Georgia IPM image website (http://www.ipmimages.org) Image courtesy of Dan Mott/Jack Bacheler: North Carolina State University

Identification

These images are somewhat deceptive because cabbage and soybean loopers are normally very difficult to tell apart. They are both green with white stripes. Each has no prolegs on the majority of their abdominal segments, which results in a looping motion. Both are also about 1½ inches long at maturity. On occasion, the soybean looper may have black thoracic legs (true legs), but some do not so this is not a reliable diagnostic tool.

Adult:

Both adults have about a 1½-inch wingspan. The cabbage looper is mottled brown with two white or silver spots near the center of the forewing that looks like a figure eight. The soybean looper is also mottled brown with two silver spots near the center of the forewing, which is also occasionally described as a figure eight.

	Image courtesy of Dr. Ron Smith: Auburn University and University of Georgia IPM image website (http://www.ipmimages.org)

Pupa:

Both soybean and cabbage looper spin loose cocoons in which to pupate. The cocoons are attached to the underside of leaves.

Biology

Both cabbage looper and soybean looper have similar life cycles. Both overwinter as pupae. In the spring when the temperatures warm, adults emerge. Females begin to oviposit on preferred hosts soon after emerging. Eggs hatch in 2 to 3 days and larvae begin to feed immediately on leaf tissue. Larvae feed for 2 to 4 weeks and then pupate. Multiple generations can occur in the southern United States. A complete life cycle can be completed in 25 days for the soybean looper and 35 days for the cabbage looper.