No-till corn is subject to slug damage. This problem is severe when cool, wet springs facilitate abundant slug populations. Field slugs vary in size depending on the species, but most slugs found feeding on corn are less than 1 inch long. When abundant, slugs can cause extensive damage to the point that the stand is significantly reduced and replanting may be warranted. Slug feeding damage is similar to that of insects, but slugs leave telltale slime trails.
Slugs mainly feed at night and during moist, cool early-morning hours.
During the day, they seek dark, moist conditions and may move deep into the soil, making detection difficult. In minimum-tillage fields where corn has been grown, inspecting the base of old corn stubble will usually uncover any slugs. Severe slug problems are most likely to occur where no-till practices are used for a continuous period of time. Adoption of minimum tillage practices may be warranted in place of no-till to prevent losses due to slugs when populations become established and problems occur repeatedly. Grower-prepared slug baits that use cracked corn as a carrier and a toxicant under a special state or emergency label are no longer feasible due to public and regulatory attention that has focused on potential effects on avian wildlife.