Statewide Slug Monitoring Project – update # 2

This is our second update on slugs in Ohio, funded by the United Soybean Board. Compared to last week, slug activity has picked up this week and we expect numbers to continue to increase as the weather warms up and fields are planted across the state.

Slugs are a concern for growers in Ohio because growers, especially those with no-till fields where cover crops are grown. Slug numbers are increasing and evidence of plant damage resulting from slugs is becoming more common. Slugs may not be noticeable at first because they are a nocturnal pest, meaning they feed at night the majority of time. We also tend to find slugs feeding on cloudy or rainy days. Both of these situations are not ideal for scouting, so slugs are often missed until damage is noticeable. Slugs feed directly on soybeans causing both seed and foliar damage that can result in complete loss of the plant (Figure 1).

Figure 1. Slug feeding on soybean cotyledon in the field. Photo credit, Amy Raudenbush.   

As a reminder, please take a look at our new “Slug Biology and Management” card that can be viewed here: “Slug_Biology_and_Management”. In addition, more information can be found on this slug fact sheet: Slug_Fact_Sheet.

For our second report we monitored from April 27^th to May 3^rd. During this time, we had 20 counties monitoring a total of 150 shingle traps. Six out of the twenty counties reported slug activity over the past week (Figure 2). The number reported is the average number of slugs found under the traps. All of the monitoring counties had an average of less than 1 slug per field this week. Overall, the number of counties with slugs is up from the previous week where we had only one county reporting slugs. We intentionally set our traps out earlier this year to try and find when slugs would start emerging in our fields. The increase in slug numbers tells us that slugs are now active in parts of Ohio and over the next couple of weeks, as the weather gets a little warmer and more fields get planted, we expect these numbers to continue to increase.  Stay tuned for more slug updates!

Slugs in Ohio: April 27^th – May 3^rd, 2026

Figure 2. Average slugs found from April 27^th to May 3^rd. The bold number on the left indicates the average slug count for the week, followed by the standard number on the right which indicates the total traps set up in that county. Each field monitored has a total of 6 traps.