Evaluating the influences of straw mulch on the biodiversity of ground beetle (Coleoptera: Carabidae) communities in potato fields across Idaho

Idaho is a high-agriculture state with a diverse set of crops, including alfalfa, hops, onions, sugar beets, and potatoes. Even though its productivity and revenue are high, the expansion of conventional agriculture is known to negatively impact the environment. However, regenerative agriculture practices like straw mulch have been shown to aid in mitigating the effects of conventional farming practices. Fields placed with straw mulch have shown benefits in increasing soil retention and yield grade. In addition, straw mulch can influence the abundance of predatory insects like Geocoridae and Anthocoridae (Hemiptera). However, the effect of straw mulch on ground predators like ground beetles (Coleoptera: Carabidae) remains unknown. We aim to fill this knowledge gap by assessing the influence of straw mulch on the community of carabids in Idaho. In the summer of 2025, we evaluated three straw-mulch densities in potato fields across southern Idaho (n=3). Treatments included no straw mulch (control), low-density (1600 lbs/Acre), and high-density (3200 lbs/Acre). We expect a positive relationship between the mulch density rates and species richness, and a lower activity density of beetles in plots where the straw mulch was applied. This study aims to understand the additional benefits of straw mulch and its influence on carabids in Idaho potato crop fields. Ultimately, this practice will seek to advance sustainable farming practices that encourage beneficial insects and enhance IPM strategies across the Pacific Northwest.