Fontanelle
Making the difference for you
Wireworms and Cutworms
December 31, 1969
By Gabe Hardman
Fontanelle Regional Agronomist
As corn emerges, seedlings become susceptible to insect pressure. Wireworm and cutworm are two major insects that feed on corn seed or emerging seedlings early in the spring.
Granular and liquid insecticides protect the corn when insect pests come into contact with the insecticide. These insecticides must be applied as a T-band in order to be effective against cutworm. Seed applied insecticides, most notably Cruiser® and Poncho®, have gained popularity by offering both contact and systemic control of early season pests.
Wireworms are the first insect pests to show up in corn. They feed on ungerminated kernels and young seedlings thus reducing corn stands. All wireworm feeding occurs below the soil surface. Soil applied and seed treated insecticides are an effective control measure, but no affective rescue treatments are available.
Black and dingy cutworms are two common species of cutworms that feed on corn in central and eastern Nebraska, but can cause damage throughout the corn growing regions. Dingy cutworms feed mostly on leaves and less frequently clip plants. Treatment thresholds are much higher for dingy than black.
Black cutworms cause most of the economic damage from cutworms in central Nebraska. They feed both on leaf tissue and clip plants. Black cutworms clip plants by cutting stalks and feeding at the base of the plant.
Cutworms, most commonly infest fields with heavy winter annual weed and grass pressure. Also, cutworm infestation may first show up along field edges bordered by grass ditches and waterways.
If economic thresholds are reached, generally 5% clipped plants or more, cutworms can easily be controlled with rescue treatments using inexpensive insecticides.
Monitor fields this spring for early season insect pressure. Insecticides applied at planting are effective at controlling early season pests but are not fail proof.