1st Place: D3042: Enhancing biological control by ground beetles (Coleoptera: Carabidae) through agricultural drainage ditch management practices

Conservation biological control (CBC) seeks to mitigate insect pest damage by utilizing existing natural enemies on farms. Many species of ground beetles (Coleoptera: Carabidae) are widespread generalist predators that feed on a variety of important insect pests. While agricultural drainage ditches function to enhance groundwater flow from crop fields, they also represent habitats with high plant and arthropod biodiversity relative to adjacent crops and therefore may represent a source of natural enemies for CBC. Our objectives are to 1) quantify the diversity and abundance of carabids in ditches, 2) investigate movement of carabids between ditches and crop fields, and 3) compare the effects of ditch management practices on carabids including timing of mowing and spreading of straw along ditch banks. Sweep, sticky trap, and pitfall trap samples were collected from agricultural drainage ditches on the Eastern Shore of Maryland throughout summers from 2020 to 2022. Directional pitfall traps were placed along ditch margins to assess proportions of carabids running in each direction. Ditches at six farms across the Eastern Shore were sampled for objectives 1 and 2. For objective 3, mowing and straw treatments were applied during the fall and spring to plots along a ditch at one farm in a randomized block design. Thus far, we observed high abundance and diversity of ground-running carabids within ditches and adjacent crops. Results of this study can be used to provide farmers with an additional tool to increase the activity of natural enemies and reduce damage caused by pests.