Land cover and climate drive shifts in Bombus assemblage composition

Bumble Bee Responses to Climate and Landscapes: Investigating Habitat Associations and Species Assemblages Across Geographic Regions in the United States of America

“…While research is underway to understand the broader impacts of pest monitoring traps on bumble bees at a national scale (Spears and Ramirez, 2015; Spears et al, 2016, 2021; Christman et al, 2022a), science policy is needed to make actionable change. With informed science policy, innovative management practices and mandates can be employed that meet multiple federal agency’s goals, while also preventing the least amount of harm to agriculture, natural resources, and imperiled species.…”

“…Bumble bees were collected within pest monitoring traps that were placed by state cooperators in agricultural fields across diverse regions in the USA as part of early-detection surveys for invasive lepidopterans following Spears et al, (2016) and U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Cooperative Agricultural Pest Survey approved methods for pest surveillance (CAPS, 2022). Previous research identified that bumble bees are attracted to pest monitoring traps and suggested that these captures be used to advance knowledge of biodiversity, population fluctuations, and other ecological objectives (Buchholz et al, 2011; Spears and Ramirez, 2015; Sipolski et al, 2019; Whitfield et al, 2019; Grocock et al, 2020; Grocock and Evenden, 2020; Parys et al, 2021; Spears et al, 2016, 2021; Christman et al, 2022a).…”

“…Target pests included Christmas berry webworm (CBW, Cryptoblabes gnidiella Milliere, 1867), cotton cutworm (CC, Spodoptera litura Fabricius, 1775), Egyptian cottonworm (EC, Spodoptera littoralis Boisduval, 1833), golden twin spot moth (GTS, Chrysodeixis chalcites Esper, 1789), Old World bollworm (OWB, Helicoverpa armigera Hübner, 1808), and silver Y moth (SYM, Autographa gamma Linnaeus, 1758). Following methodology outlined in Christman et al (2022a) and CAPS (2022), multi-colored (green canopy, yellow funnel, and white bucket) bucket traps (International Pheromone Systems, Cheshire, UK) were placed 20 m apart and hung 1.5 m above the ground along the edge of vegetable or other commodity crop fields (e.g., alfalfa, corn, small grain) as part of the CAPS monitoring program. Each trap contained a pheromone lure for a single target pest inside the lure basket of the trap canopy.…”

“…For example, imperiled B. occidentalis range-wide declines have been attributed to increasing temperatures during the warmest quarter of the year, severe drought years, and use of nitroguanidine neonicotinoid insecticides, while their occupancy is positively associated with increased forest and shrub area (Janousek et al, 2022). Meanwhile, previous research in Utah identified that bumble bee assemblage composition was highest at agricultural sites surrounded by more agricultural land cover, low temperatures, and high relative humidity, and lowest at agricultural sites with more urban land cover in the surrounding area, high temperatures, and low relative humidity (Christman et al, 2022a). Further, land use can amplify or offset changes in suitable habitat for bumble bees under various climate projections, emphasizing the importance of utilizing targeted land management practices on top of climate mitigation techniques to reduce the magnitude of bumble bee declines (Prestele et al, 2021).…”

Bumblebee occupancy responds to complex interactions between local and landscape land use, climatic niche properties and climate change

“…The availability of natural or semi-natural habitats in the landscape has been shown to be important for sustaining the diversity of bees, as well as improving individual and colony performance, including in agricultural habitats (12,(25)(26)(27)(28). However, effects often depended on the species and/or the nature of the natural habitat (8,28,29), and sometimes were absent or negative, for example when farmed areas provide abundant floral resources (25,30). At the same time, farming practices within agricultural land uses may impact biodiversity within natural habitats.…”