Cabbage Looper
Description:
The caterpillar (larva) grows to be about 2 inches long, is light green and has three pairs
of "true" legs behind the head plus pairs of fleshy "false legs" (prolegs) on the 3rd,
4th and last or 6th segments behind the segment with the last pair of true legs (the abdominal segments).
This arrangement of legs causes the caterpillar to crawl with a "looping" motion,
similar to that of inchworms. Some specimens are marked with light stripes along the body.
Adult moths are mottled grayish-brown with a 1 1/2 inch wingspan. Each forewing is marked
near its center with a pair of characteristic silver markings: a spot and a mark resembling
a "V" or and "8" with an open end.
Life Cycle:
Winter is spent in the pupal stage inside of a cocoon attached by one side to the host
plant material. Adults emerge in the spring, mate and fly to a suitable host plant.
Eggs are smooth, light green and slightly flat. Within about 3 days, small caterpillars
hatch from the eggs. During a period of about 4 weeks caterpillars feed and develop
through several stages (instars) before spinning a silk cocoon in which they form a
greenish to brownish 3/4 inch long pupa. Adults emerge in about 13 days unless they
overwinter. Development from egg to adult can be completed in about 35 days. Four
generations or more can be produced each year.
Pest Status:
Caterpillars have chewing mouthparts. Adults have siphoning mouths.
Cabbage loopers feed on leaves of a wide variety of plants, including beets,
cabbage, carnation, cotton, kale, lettuce, nasturtium, parsley, peas, potato,
soybeans, spinach, tomato. Injured leaves appear tattered, with irregularly
shaped holes removed between major leaf veins. Adults are attracted to lights at night.
One of the most common caterpillars found in garden and bedding plants.
Control:
Outbreaks of this pest are not common because they have many natural enemies.
Handpick caterpillars several times a week. Use botanical insecticides only as a last resort.
After harvest, bury spent cole crops to destroy cocoons before adults emerge in spring.
