Common Name: Cabbage Looper
Latin Name:Trichoplusia ni
Main Host(s): Cole crops but also lettuce, celery, tomato and a wide range of other vegetables.
Cabbage Loopers are native to North America and only overwinter in the warmest Southern areas, such as Florida.
The adults can travel great distances, migrating in the springto Northern regions and arriving even in Canada in July and August.
Female Cabbage Looper moths lay pale green eggs, singly or in small clusters of half a dozen mostly on the undersides of leaves but some on upper leaf areas. The eggs hatch in 3 to 4 days, but even as they go through the five larval stages over the next 18-25 days, the larvae generally remain on the undersides of leaves because they are photosensitive. The larvae move in a looping motion, hence the name “Looper”.
Pupation occurs in the fall and the pupae overwinter followed by emergence in the Spring.
Impact & Damage
In warm climates, Cabbage Loopers can have up to seven generations a year and can cause tremendous damage to vegetable crops. Due to easy identification and determination of feeding damage, the Cabbage Looper is a designated standard for assessing caterpillar pest presence and the timing of insecticide applications.
Scouting and early detection of Cabbage Loopers is particularly critical. Many growers use sex pheromone traps to monitor incoming adults. After adults have been found, scouting for eggs begins. Both DiPel®, with Bt subspecies kurstaki, and XenTari®, with Bt subspecies aizawai as active ingredient are excellent strategies against the Cabbage Looper. Feeding damage assessment during the course of the growing season is important to know when to initiate spray applications. Bt should be applied when egg masses are mature and insects are beginning to hatch. Significant feeding begins with the second instar, not the first, so most growers find that if they apply a thorough coverage of a Bt within a couple of days of egg hatch, they can avoid serious economic damage.
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