Pest Information
Common name: Cabbage looper
Scientific name:
Trichoplusia ni
Lepidoptera:Noctuidae
Host plants
Cabbage, collards, broccoli, cauliflower, celery, pea, potato, spinach, lettuce, parsley, tomato, tobacco, cucumber, cotton, soybean
Distribution
Asia, Africa, Central America, eastern coast of USA. T. ni is widely distributed but is usually considered to be of tropical or subtropical origin.
Damage
Larvae feed primarily on leaves causing irregular, rugged holes, bore through the heads, and contaminate heads and leaves with their
frass (excreta). Their frass stain cauliflower heads and make broccoli heads unmarketable. Large larvae can burrow through 3-6 layers of tightly wrapped head leaves in cabbage. Plants can be severely defoliated and stunted, producing no head or be unfit for consumption. Sometimes, they damage the seedlings, but heavy injury usually occurs after heading.
Description
The egg is very small and bowl-shaped with a flat side, yellowish to greenish-white in color, and found singly lying on the leaves.
The larva is light green and about 3-4 cm long when fully developed. It has 3 pairs of slender legs near the head and 3 pairs of thickened
prolegs on the abdomen. It moves by arching its back to form a loop
and then projecting the front section of the body forward. It usually feeds on the leaves and into the cabbage head.
The pupa is green or brown in color and is nearly 2 cm long. It is enclosed in a flimsy, silken
cocoon. Pupation occurs in a folded webbed leaf or between two webbed leaves.
An adult is a grayish-brown moth and has a wingspan of about 3.3-3.8 cm. Each of the
mottled and brown front wings which bears a small and silvery-spot that resembles like a figure 8. The hindwings are paler-brown. Adults are strong
fliers and are primarily
nocturnal. During the day the adults can be found resting in
foliage or in crop debris. Moths feed on various wild and cultivated hosts where they obtain water and dissolved nutrients. A female moth can produce 300-1600 eggs.