Identifying wild bee visitors of major crops in North America with notes on potential threats from agricultural practices

Abstract

Considering the critical importance of insect pollination to food security and documented declines in wild bee populations, it is imperative to develop effective conservation and management strategies that promote the health of wild bee communities associated with agroecosystems. Identifying wild bee visitors of crops, including crop-flower visitors and species that nest within cropping areas, may prove critical to this endeavor as optimal conservation strategies may differ among bee species and/or guilds, regions, and cropping systems. Although lists of bee species that are associated with North American crops are scattered throughout the literature, there is a need for a comprehensive compilation of those species by crop, region, and nesting guild. Here, we searched the literature to compile a list of wild bee species associated with 33 major crops in North America and assessed the overlap in bee species communities among crops and regions. Of the 739 crop-associated bee species retrieved, 405 species (54.8%) were ground nesters, and 438 species (59.3%) were identified as crop-flower visitors of at least one crop. Because of their nesting and foraging behavior, we argue that these species are more likely to be exposed to agricultural pesticide residues than bee species that do not nest in the ground or feed directly on crop flowers. We further compiled lists of wild bees that have been found to be associated with all of the four most surveyed perennial fruit crops (apple, blueberry, cranberry, strawberry) and all of the three most surveyed cucurbit crops (cucumber, Cucurbita, watermelon) in eastern North America. These lists of bee species can be used to focus attention on species needing better protection strategies within agroecosystems, especially for these two important North American crop groups and can also inform the development of multi-species pesticide risk assessment schemes.

Safeguarding pollinators requires specific habitat prescriptions and substantially more land area than suggested by current policy

“…If the goal is to safeguard wider pollinator biodiversity (species richness), more habitat and distinctly different habitat types are required (Fig. 4 ) than if the goal is to enhance crop pollination through increasing the abundance of specific functional groups or indeed particularly important species that dominate crop flower visitation 33 , 34 (Fig. 2 ; Table 2 ).…”

Combining community science and taxonomist expertise for large‐scale monitoring of insect pollinators: Perspective and insights from Abeilles citoyennes

“…An impressive number of specimens (>16,000) have been collected by community scientists during the project, permitting the identification of ≥252 species of bees (out of a total of 298 species recorded for Quebec; The Royal Saskatchewan Museum (2023)) and 86 species of hover flies (out of 413 species known in Eastern North America; Skevington et al (2019)). In comparison, a recent review of the bee fauna associated with agriculture in North America reported a total number of 185 bee species for the Province of Quebec from 11 monitoring studies conducted between 1967 and 2021 (Rondeau et al, 2022) while 200 species were reported for the cities of Montreal and Quebec (Normandin et al, 2017). For hover flies, previous studies have reported a total number of 28 species in lowbush blueberry (Moisan‐DeSerres et al, 2015), 33 species in cranberry crops (Gervais et al, 2018), and 48 species in urban green spaces (McCune et al, 2023).…”

“…), several species of which have been shown to be declining in the province of Ontario and western Canada (Colla & Dumesh, 2010;Colla & Packer, 2008;Colla & Ratti, 2010;Macphail et al, 2019). In Quebec, short-term surveys have been conducted in agricultural (Gervais et al, 2017(Gervais et al, , 2018Moisan-Deserres et al, 2014;Moisan-DeSerres et al, 2015;Rondeau et al, 2022;Slupik et al, 2022) and urban (MacInnis et al, 2023;Martins et al, 2017;Normandin et al, 2017) areas, but more work is needed to reliably assess trajectories of wild bee communities over time and to forecast their resilience to ongoing and future perturbations.…”

“…As such, historical baseline data on insect pollinator populations at larger scales (that are both biologically and geographically relevant) are rarely available (Woodard et al, 2020). This lack of data limits the identification of pollinator communities that require conservation actions as well as those that need special attention because of the extended services they provide to ecosystem function and crop production (Rondeau et al, 2022; Woodard et al, 2020).…”

Unveiling the submerged secrets: bumblebee queens' resilience to flooding

“…These queens are the only individuals that survive the winter, while the workers and males perish before the winter months. While allowing the queens to escape the cold, underground overwintering means that diapausing queens are exposed to various stressors such as parasites [8,9], mould [10,11], soil contaminants [12][13][14] and flooding [15].…”