title: Ground beetle (Coleoptera: Carabidae) phenology, diversity, and response to weed cover in a turfgrass ecosystem.
abstract: Despite being fragmented and highly disturbed habitats, urban turfgrass ecosystems harbor a surprising diversity of arthropods. The suitability of turf as arthropod habitat, however, likely depends on the extent and types of pesticides and fertilizers used. For example, moderate levels  of weed cover in low-input lawns may provide alternative food resources. We conducted a 2-yr field study to: 1) characterize the ground beetle (Carabidae) species assemblage in turfgrass, and 2) assess the direct and indirect effects of lawn management on carabid communities. Weed cover and  beetle activity were compared among four lawn management programs: 1) consumer/garden center, 2) integrated pest management (IPM), 3) natural organic, and 4) no-input control. Nearly 5,000 carabid beetles across 17 species were collected with the predator Cyclotrachelus sodalis LeConte numerically  dominating the trap catch (87% and 45% of individuals in 2005 and 2006, respectively). Populations of C. sodalis underwent a distinct peak in activity during the third week of June, whereas omnivorous and granivorous species tended to occur at far lower levels and were less variable over the  season. We found no evidence for direct effects of lawn management on carabid species diversity; however, we detected an indirect effect mediated by variation in weed cover. Seed-feeding species were positively correlated with turf weeds early in 2006, whereas strictly predaceous species were  not. Thus, turf management programs that lead to changes in plant species composition (i.e., herbicide regimes) may indirectly shape epigeal arthropod communities more strongly than the direct effects of insecticide use.
authors.affiliation: Department of Entomology, Purdue University, West Lafayette, IN 47907, USA. blubaugh@purdue.edu
authors.forename: Carmen K
authors.initials: CK
authors.lastname: Blubaugh
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Caceres
authors.forename: Ian
authors.initials: I
authors.lastname: Kaplan
authors.forename: Jonathan
authors.initials: J
authors.lastname: Larson
authors.forename: Clifford S
authors.initials: CS
authors.lastname: Sadof
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Richmond
mesh_terms: D000818:Animals; D044822:Biodiversity; D001517:Coleoptera; D005308:Fertilizers; D010575:Pesticides; D057685:Plant Weeds; D006109:Poaceae; D011897:Random Allocation; D058728:Weed Control
chemical_list: D005308:Fertilizers; D010575:Pesticides