Cutworms on Vegetables

We have seen a couple of cases of cutworm injury to vegetables in the last two weeks, and it is a good time to remind growers of the importance of scouting for this potentially damaging pest. Several species of cutworms are found in North Carolina, and they can cause serious damage to a wide range of crops including vegetables in both the home garden and commercial production. Cutworms are most damaging in the spring when they feed on young transplants or newly emerged seedlings. Depending on the species, larvae may be found in the soil around the base of plants or on foliage. Cutworms typically hide during the daylight hours and feed at night or on cloudy days. The black cutworm is one of the most destructive cutworms in North Carolina; it severs plant stems close to the soil surface and will move down rows feeding on multiple seedlings each night. This feeding can result in significant stand losses in a very short period of time.

Cutworms overwinter as larvae or pupae in the soil. Moths emerge in the spring, mate and lay eggs on weedy vegetation or crop plants. Conservation tillage and planting into fields where winter weeds were recently disked increases the risk of cutworm infestation. Destroying winter weeds at least two weeks prior to planting spring crops and managing the crop to ensure good seedling vigor will reduce the risk of losses from cutworms.

It is important to scout seedling vegetables regularly for cutworm damage. Prevention is the first line of defense against this pest, but chemical control is often needed when infestations occur. Refer to the North Carolina Agricultural Chemicals Manual (http://ipm.ncsu.edu/agchem/agchem.html) for cutworm management recommendations in specific crops.

From: Mark Abney, Extension Entomologist

Forest Tent Caterpillar

We most often talk about the Eastern tent caterpillar which seems to be the greater pest in the landscape attacking crabapple, cherry, and related trees. Less common in most areas is its cousin the forest tent caterpillar, which has similar appearance but a broader host range including most hardwood trees such as oak and maple. Historically, there have been some major outbreaks in eastern forests, primarily in the northern U.S. This caterpillar can be distinguished by the “key hole” markings down the back, unlike the continuous strip of the eastern tent caterpillar. The other distinguishing behavior is that they do not spin a tent as much, but rather lay a silk trail that becomes more like a mat on a trunk or branch. For more information, see the U. S. Department of Agriculture Forest Service’s Forest Insect and Disease Leaflet 9 available at http://www.na.fs.fed.us/spfo/pubs/fidls/ftc/tentcat.htm.