caterpillarScientific names: Pieris rapae (cabbage white butterfly), Trichoplusia ni (cabbage looper moth)

Order: Lepidoptera

Description: The cabbage white caterpillar is smooth and light green. When fully grown, it is slightly over 1 inch long. The adult butterfly is creamy-white with one or two sets of black dots and black edges on the upper edges of the wings. The cabbage looper caterpillar has thin white stripes along its abdomen and thicker white stripes along the sides. The adult is a spotty light- and dark-brown with a distinct silvery-white spot on the upper side of the wings.

Behavior: Both species eat leaves as caterpillars. They typically hide under leaves or near the base of the plant. Cabbage looper caterpillars lack some pairs of modified legs on the underside of the abdomen, which results in their “inching” movements. Adults fly to search for mates and new host plants. Cabbage white butterfly adults are active during the day, while cabbage looper moths are active at night. Adults of both species drink nectar from flowers.

Life cycle: Both species have similar life cycles. Following egg hatch in mid- to late-spring, the caterpillars go through several stages (or instars), lasting approximately three to four weeks. The caterpillars make silken cocoons (pupal stage) before developing into winged adults. Up to three generations per year are produced. Both the cabbage looper and the cabbage white overwinter in the pupal stage.

Diet and damage: Caterpillars of both species eat plants in the cabbage family, including cabbage, broccoli, cauliflower, kale, Brussels sprouts, collards and many others. Both caterpillars chew large holes from the leaves. Cabbage loopers start feeding on the outsides of the leaves and then move to the head of the plant. Monitoring: Frequent scouting for caterpillars is key to protecting plants. Every few days, look under leaves and stems for small caterpillars, caterpillar excrement and silk webbing.

Control methods:

Cultural: Removing grass or weedy mustards around planted rows can reduce the numbers of nearby individuals. Interplant with nonbrassica crops and mulch around plants to encourage beneficial insects. Mechanical: Regularly hand-pick and destroy small caterpillars. Apply row covers when transplanting seedlings outdoors. Till the garden at the end of the season to kill the overwintering pupal stages of the insects.

Biological: Many insects and other arthropods feed on these caterpillars, including spiders and parasitoid wasps. Look for dead or dying caterpillars with small white silk cocoons attached to their abdomens; these individual caterpillars have been parasitized. Cocoons should be left for adult parasitoid wasps to emerge.

Chemical: There are several organic and synthetic pesticides registered for brassica crops targeting the caterpillar stages of these pests, including insecticidal soaps, oils, pyrethrins, Bacillus thuringiensis var. kurstaki (Bt), Spinosad and several others. Chemical controls are most effective when applied at the early caterpillar stages, as older caterpillars are resistant to several insecticides.

When applying any pesticide, read the entire product label thoroughly before application. If you see a Bee Advisory Box, this newly developed EPA label denotes a potentially high risk to bees and other pollinators.

K. Burls, W. Hanson Mazet, H. Kratsch 2021, A Northern Nevada Homeowner's Guide to Identifying and Managing Cabbage Caterpillars, Extension, University of Nevada, Reno, FS-21-109

Extension Associated Contacts

 

Also of Interest:

 
Equipo de Protección Personal / Personal Protective Equipment (PPE)
Esta publicación describe el Equipo de Protección Personal (Personal Protective Equipment) o PPE, cuál es el requisito mínimo de un PPE para la mayoría de los pesticidas, consejos para el uso del PPE y cómo cuidarlo. Esta es una en una serie de 10 hojas que contienen datos sobre ...
Hefner, M., Fisher, J., Kratsch, H., and Schaerer, M.F. 2020, University of Nevada, Reno Extension Fact Sheet FS-20-04
Protegiendo a los Polinizadores / Protecting Pollinators
Esta publicación describe cómo proteger a los polinizadores durante la aplicación de pesticidas. También describe a las abejas nativas y proporciona recursos adicionales para obtener mayor información. Esta es una en una serie de 10 hojas que contienen datos sobre el Uso y Seguri...
Hefner, M., Kratsch, H., Fisher, J. and Schaerer, M.F. 2020, University of Nevada, Reno Extension Fact Sheet FS-20-10
Entrenamiento en la Seguridad de Pesticidas: Como Protegerte Mientras se Aplican los Pesticidas Video
El hecho de protegerte mientras se aplican los pesticidas es muy importante. Según la Agencia a cargo de la Protección Ambiental, un pesticida es cualquier sustancia o mezcla de sustancias destinadas a prevenir, destruir o repeler cualquier plaga.
Hefner, M., Kratsch, H., and Harrison, D. 2020, University of Nevada, Extension, YouTube Channel
Entrenamiento en la Seguridad de Pesticidas: Que Se Debe Hacer Cuando Hay Derrames de Pesticidas
En este video, hablaremos sobre los kits relacionados con los derrames y que se debe hacer al tratar con los derrames de pesticidas.
Hefner, M., Kratsch, H. and Harrison, D. 2020, University of Nevada, Extension, YouTube Channel
Almacenamiento Seguro de Pesticidas / Storing Pesticides Safely
Esta publicación describe la forma correcta de almacenar los pesticidas de manera segura y cómo eliminar los pesticidas no deseados. Esta es una en una serie de 10 hojas que contienen datos sobre el Uso y Seguridad de Pesticidas.
Hefner, M., Kratsch, H., Fisher, J. and Schaerer, M.F. 2020, University of Nevada, Reno Extension Fact Sheet FS-20-03
 

Associated Programs

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Master Gardeners of Washoe County

Master Gardeners provide free, research-based horticulture information to Nevadans.

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Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans

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Pesticide Safety Education Program

Extension’s Pesticide Safety Education Program provides web-based training for pesticide applicators seeking to apply restricted and general use pesticides safely, properly and according to the law. Pesticide licensure and certification is administered by the Nevada Department of Agriculture.