Arthropod predator community composition and activity-density in Nebraska grassland and adjacent row crops

Monday, November 14, 2022

10:30 AM – 10:42 AM PT

Location: Vancouver Convention Centre, Meeting Room 122

Presenting Author(s)

Hannah E. Stowe

PhD Student
University of Nebraska
Lincoln, Nebraska

Co-Author(s)

KT

Kristen Tam

University of California
San Francisco, California
Julie Ann Peterson

Associate Professor
University of Nebraska
North Platte, Nebraska

Land use and agricultural intensity can significantly alter natural enemy abundance and distribution, both within individual fields and between adjacent field boundaries. Row crop fields represent a large percentage of Nebraska’s total agriculture acreage, although interspersed perennial grasslands can be found through enrollment in the Conservation Reserve Program (CRP). Biological control can depend heavily on the presence of diverse and dynamic predatory populations and understanding landscape and edge effects on their community may be instrumental to land management decisions. Our aim is to investigate the influence of CRP and row crop fields and their intersection on arthropod predators. We collected epigeal predators using wet pitfall traps and foliar and airborne predators using sticky card traps to determine community composition and activity-density in field centers and at the shared edge of both adjacent fields. Carabid beetles predominated within crop fields, with lower activity levels in grasslands and intermediate activity on field edges. Spiders showed more complex effects; overall activity was low in border regions but higher in both the grasslands and the crop field centers, with sampling date also affecting activity patterns. Activity-density of other arthropod predators was dependent on edge proximity and land use type but varied in direction and magnitude. Such trends can reveal how environmental resource availability and seasonal cues influence arthropod activity patterns and thus ecosystem services in a complex manner, while illustrating potential spillover benefits to crop fields from adjacent perennial grasslands.