title: Increasing neonicotinoid use and the declining butterfly fauna of lowland California.
abstract: The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association between butterfly populations and increasing neonicotinoid application is detectable while controlling for land use and other factors, and appears to be more severe for smaller-bodied species. These results suggest that neonicotinoids could influence non-target insect populations occurring in proximity to application locations, and highlights the need for mechanistic work to complement long-term observational data.
authors.affiliation: Department of Biology, University of Nevada, Reno, NV, USA forister@gmail.com.
authors.forename: Matthew L
authors.identifier: 0000-0003-2765-4779
authors.initials: ML
authors.lastname: Forister
authors.affiliation: Western Purple Martin Foundation, Nanaimo, British Columbia, Canada.
authors.forename: Bruce
authors.initials: B
authors.lastname: Cousens
authors.affiliation: Department of Biology, University of Nevada, Reno, NV, USA.
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Harrison
authors.affiliation: Biology Department, Colorado State University, CO, USA.
authors.forename: Kayce
authors.initials: K
authors.lastname: Anderson
authors.affiliation: Department of Environmental Science and Policy, University of California, Davis, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Thorne
authors.affiliation: Department of Environmental Science and Policy, University of California, Davis, USA.
authors.forename: Dave
authors.initials: D
authors.lastname: Waetjen
authors.affiliation: Department of Biology, Texas State University, San Marcos, TX, USA.
authors.forename: Chris C
authors.initials: CC
authors.lastname: Nice
authors.affiliation: US Geological Survey, California Water Science Center, Sacramento, CA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: De Parsia
authors.affiliation: US Geological Survey, California Water Science Center, Sacramento, CA, USA.
authors.forename: Michelle L
authors.identifier: 0000-0002-0891-2712
authors.initials: ML
authors.lastname: Hladik
authors.affiliation: Department of Environmental Science and Policy, University of California, Davis, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Meese
authors.affiliation: Biology Department, York University, Toronto, Ontario, Canada.
authors.forename: Heidi
authors.initials: H
authors.lastname: van Vliet
authors.affiliation: Department of Evolution and Ecology, Center for Population Biology, University of California, Davis, USA.
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Shapiro
mesh_terms: D000818:Animals; D002080:Butterflies; D002140:California
keywords: butterflies; global change; insecticide; long-term ecological data; neonicotinoids