Photo Gallery
Varigated cutworm feeding on hosta
leaf. Note the yellow spots on the back.
Variegated cutworm
hiding at base of hosta leaf on a cloudy day.
The most distinguishing characteristic of the variegated cutworm is the 4 to 7 pale yellow, circular spots on the back of the larva. Its general body color is variable, but usually brown. The underside of the caterpillar is cream colored. There is a narrow, orange-brown stripe along the side. The adult moths have grayish brown forewings and have a pale oval marking near the wing edge, adjacent to a darker kidney-shaped marking.
The variegated cutworm overwinters in states to the south of North Dakota. Moths migrate to the region during the spring and summer months. There are multiple generations of this cutworm, numbering two to three, depending on environmental conditions.
Host(s):
The variegated cutworm has a wide range of host plants which includes field, forage, vegetable and ornamental plants. The variegated cutworm is one of the most important cutworms on vegetables, damaging potato and tomato.
Damage/Symptoms:
Nearly all fruits, vegetables and ornamental plants can be damaged by variegated cutworms. Damage is especially common on hosta, petunia and other low growing, "fleshy_leafed" plants. Feeding on hosta foliage causes large irregular holes at the leaf margins or oblong holes within the leaf bounded by veins. Destruction of emerging leaves at the center of the crown can be nearly complete.
Variegated cutworms large enough to cause noticeable damage are usually at least 1/2 to 3/4 inch long. They ultimately grow to be 1 1/2 inch. Like other cutworms, variegated cutworms are nocturnal and feeding takes place at night or on very cloudy days, meaning few people have seen the cutworms though many are familiar with the large irregular holes noticed later.
Comments:
Vegetable gardeners, homeowners with hostas, and others are having a difficult time in eastern North Dakota due to a large migration of variegated cutworm moths into the region this spring. The variegated cutworm is found in sites as varied as alfalfa fields to home gardens. This cutworm is referred to as a "climbing" cutworm because of its habit of climbing plants at night to feed on foliage, flowers, buds and fruits. Variegated cutworms do not damage plants by clipping at ground level as is typical of many cutworms.
Control can be as simple as raking around the base of damaged plants with your fingers until you find the culprit. The brown cutworms blend well with the color of mulch and soil and careful searching will be necessary. Searching for cutworms at night and discarding all that are found feeding on plant foliage is another possible mechanical control.
Larger problems with variegated cutworms can be controlled by treating the soil around damaged plants with Sevin, permethrin, cyfluthrin, bifenthrin, or diazinon. If treating vegetable crops, select only insecticides approved for application to those edible crops.
