Project Details:

Title:
Control of Slugs in a Multi-Trophic Context: Using Friends to Manage Foes

Parent Project: This is the first year of this project.
Checkoff Organization:Delaware Soybean Board
Categories:Insects and pests
Organization Project Code:
Project Year:2018
Lead Principal Investigator:Ivan Hiltpold (University of Delaware)
Co-Principal Investigators:
Keywords: ground beetles, plant volatiles, Slugs

Contributing Organizations

Funding Institutions

Information and Results

Comprehensive project details are posted online for three-years only, and final reports indefinitely. For more information on this project please contact this state soybean organization.

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Final Project Results

Updated November 5, 2019:
In a series of olfactometer experiments, we have demonstrated that ground beetles are indeed responding to plant volatiles emitted by soybean fed on by slugs. We have tested three cultivars together in on olfactometer setting, and the beetles appeared to preferentially choose Cultivar 1 over Cultivar 2 and 3. These two last cultivars didn’t attract the ground beetle significantly more than the empty control arms.

In a second set of experiments, we have tested the beetle response to either a soybean plant damaged by a slug, a healthy soybean plant, a slug only, and soil only. Again, differences were observed between cultivars. The beetles were spending significantly more time in the arm with the damaged Cultivar 1 than in any other arm. Slugs only were more appealing to the predatory insects than the plant alone or bare soil, and no distinction could be made between healthy plants and bare soil. Similar behavior was recorded with Cultivar 2, however, when exposed to Cultivar 3, the predatory beetles didn’t express any preference of the proposed treatments, even for the slugs alone. The volatiles emitted from the damaged plants, the healthy plants and the slugs only are currently collected and analyzed. We are currently designing experiments to better understand the mechanistic of the defense induction by slugs in soybean (along with the volatile collection and analyzes).

Based on the data collected, it seems very clear that predatory ground beetles do respond to soybean cues emitted after slug damage. However not all cultivars are equally defended against slug herbivory as some were not recruiting the natural enemies of the mollusk herbivores. This has never been demonstrated with slugs before and will therefore be a
nice addition to the current body of literature. In addition, this information can be useful to breeders and growers willing to use ecosystem services to manage slugs in soybean. More has to be done to really understand these interactions but this first step is very promising and opens a lot of new avenues both in research and applications. One avenue could be to
use cover crops to conserve ground beetle populations over winter.

View uploaded report PDF file

The project "Control of Slugs in a Multi-Trophic Context: Using Friends to Manage Foes" found that ground beetles are respond to plant chemcials emitted by soybeans fed on by slugs. Based on the data collected, it seems very clear that predatory ground beetles do respond to soybean cues emitted after slug damage. However not all cultivars are equally defended against slug herbivory as some were not recruiting the natural enemies of the mollusk herbivores. This has never been demonstrated with slugs before and will therefore be a nice addition to the current body of literature. In addition, this information can be useful to breeders and growers willing to use ecosystem services to manage slugs in soybean. More has to be done to really understand these interactions but this first step is very promising and opens a lot of new avenues both in research and applications. One avenue could be to use cover crops to conserve ground beetle populations over winter.

Project Years