Statewide Slug Monitoring Project – Update # 1

This is our second year of our multi-state project to monitor slugs funded by the United Soybean Board. The goal of this research is to have a better understand of slugs in soybean in states across our region. This year, we have 23 counties participating in the shingle monitoring.

Slugs continue to be a concern for growers in Ohio because growers, especially those with no-till fields where cover crops are grown, are seeing increasing evidence of plant damage resulting from slugs. 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 the damage is noticeable. The slugs feed directly on soybeans causing both seed and foliar damage that can result in complete loss of the plant (Figure 1).

In order to monitor, each field will be using shingle traps for 9 weeks (3 weeks before plant, and 6 weeks after plant). Shingle traps consist of a 1-sq.ft. white roofing shingle secured to the ground with tent stakes and are known to provide a refuge for slugs to hide under during daylight. Each week, traps are checked in the morning by lifting the shingle and counting the number of adult and juvenile slugs underneath each trap. The data collected from this study will allow us to have a better understanding of the slug variations in Ohio and across the region.

Figure 1. Slug feeding on soybean cotyledon in the field.   

For our first report covers monitoring from May 5^th to May 11^th. During this time, we had 17 counties monitoring a total of 149 shingle traps. Because of the rain many fields have not been planted, and our slug numbers are low. Our highest slug average over the past week was 2.0. We will continue to update slug numbers as the season continues, so stay tuned for slug updates over the next few weeks!

Slugs in Ohio

May 5^th – May 11^th

Figure 2. Average slugs captured from May 5^th to May 11^th. 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.