Commercial Bombus impatiens colonies function as ecological traps for wild queens

Abstract

In response to anthropogenic environmental change, the cues that animals use throughout their lifecycle to optimize fitness may become unreliable, resulting in an ecological trap. Here we investigated whether commercial bumble bee Bombus impatiens colonies managed for early spring crop pollination act as ecological traps for wild nest‐searching Bombus queens by subverting their natural nest usurpation behaviour. An average of 10 dead wild queens were recovered from each standard colony during the 2‐week period of the experiment, but colonies with queen excluders were successful in preventing wild queen deaths. The use of queen excluders did not impact colony performance in terms of resident queen survival, colony reproduction, colony weight gain or worker body size. Sites where wild nest‐searching queens were small had higher rates of failed usurpation, suggesting smaller‐sized queens are disproportionately at risk from failed usurpation. Furthermore, sites where commercial colonies without queen excluders were introduced for spring crop pollination had fewer bumble bee visits to a later‐blooming crop compared to sites without commercial colonies. Synthesis and applications. Our findings reveal a novel mechanism by which commercial colonies can negatively impact wild bumble bee populations and their pollination services. At the same time, we demonstrate a simple and inexpensive risk mitigation tool—a queen excluder—was 100% effective at eliminating this risk without compromising colony performance. Commercial colonies used outdoors during the bumble bee nest‐searching period should be fit with queen excluders to prevent negative impacts on wild pollinator communities and their services.

Niche analyses and the potential distribution of four invasive bumblebees worldwide

“…These factors may affect behavior, physiology, reproduction, and species distribution, impacting the foraging areas and the ecosystem, which are important variables affecting these species (Gérard et al., 2022 ). However, the adaptations in some species of Bombus , such as the physiological mechanisms of thermoregulation and other key factors (Dafni et al., 2010 ; Wynants et al., 2021 ), together with the commercialization events in different countries and the poor management in the culture greenhouses, have potentiated the invasion processes in different regions of the world (Acosta, 2015 ; Sutherland et al., 2017 ), promoting potential mating with wild bees (Kubo et al., 2023 ; Miller et al., 2023 ; Naeem et al., 2018 ) and competition for resources with native species, to the degree of putting them at risk of extinction (Dafni et al., 2010 ; Esterio et al., 2013 ; Hallmen, 2017 ; Madjidian et al., 2008 ; Morales et al., 2013 ; Naeem et al., 2018 ; Pérez & Macías‐Hernández, 2012 ; Sachman‐Ruiz et al., 2015 ).…”

“…mating with wild bees (Kubo et al, 2023;Miller et al, 2023;Naeem et al, 2018) and competition for resources with native species, to the degree of putting them at risk of extinction (Dafni et al, 2010;Esterio et al, 2013;Hallmen, 2017;Madjidian et al, 2008;Morales et al, 2013;Naeem et al, 2018;Pérez & Macías-Hernández, 2012;Sachman-Ruiz et al, 2015).…”

Identifying conservation priority areas for North American bumble bee species in Canada under current and future climate scenarios

“…Agricultural areas, particularly intensive agricultural areas, may lack high quality habitat, often use pesticides which can be harmful, may be a source of pathogen exposure and sites of high competition for floral resources from managed bees (Cameron & Sadd, 2020; Colla et al, 2006; de Pereira et al, 2021; Grixti et al, 2009; Siviter et al, 2023; Szabo et al, 2012). Agricultural lands within conservation priority areas should be managed for more bee‐friendly practices including incorporating semi‐natural habitats, reducing or eliminating pesticide use, restricting the spread of disease from managed bees and providing enough natural floral resources to mitigate competition (Crone & Williams, 2016; Hemberger et al, 2021; Klatt et al, 2020; Miller et al, 2023; Purvis, Meehan, & Lindo, 2020). Grasslands are also commonly represented within conservation priority areas although they are some of the most at risk land cover types in the world (Carbutt et al, 2017; Hoekstra et al, 2005).…”

Herbivore and pollinator body size effects on strawberry fruit quality

“…In total, our average bee ITD was 3.47 ± 0.36mm (mean ± 1SD). Miller et al [ 25 ] used commercial hives in the same region of New York State and found an average bee ITD of 3.34 ± 0.45mm (mean ± 1SD) and in nearby Southern Quebec, Gervais et al [ 26 ] found an average ITD of 3.943 ± 0.318mm (mean ± 1SD). Both studies measured body size later in the season, to ensure that body size (a plastic trait affected by available resources) was a reflection of the landscape’s resources and not the method by which they were commercially raised.…”