scholarly journals Novel data support model linking floral resources and honey bee competition with bumble bee abundances in coastal scrub

2021 ◽  
Vol 27 ◽  
Author(s):  
Diane M Thomson

Growing evidence supports that many bee populations are declining, with potentially serious consequences for pollination services. Mechanistic models that predict bee abundances from drivers like floral resource availability can be a powerful way to understand and address declines, but remain rare and largely unvalidated. I used temporally and spatially novel data to validate previous analyses linking bumble bee (Bombus spp.) declines in California coastal scrub with loss of floral resources, mediated by drought and competition with non-native honey bees (Apis mellifera). New observations from 2015-2018 were combined with data from 1999-2014 to further test these mechanistic hypotheses and evaluate predictions of a statistical model for Bombus abundances. As predicted, positive associations between spring rainfall and floral abundances and between Bombus and key forage plants were consistent between time periods. Increased A. mellifera abundance corresponded with reduced Bombus use of the most abundant forage plant and lower Bombus abundances in the following year. Quantitative predictions from the Bombus statistical model previously developed for 1999-2014 were relatively unbiased and strongly rank correlated with either spatially or temporally novel data. However, the model consistently underpredicted Bombus abundances when both flower patch and time period were novel. Overall, four new years of data further strengthen evidence that loss of floral resources due to drought and competition with feral Apis mellifera is an important cause of Bombus decline in this habitat. These findings reinforce the value of even simple models that are mechanistically framed, both in understanding past patterns of change and for qualitative prediction. 

2017 ◽  
Vol 149 (2) ◽  
pp. 204-213 ◽  
Author(s):  
S.D. Gillespie ◽  
J. Bayley ◽  
E. Elle

AbstractIntegration of pollinator-dependent invasive plants into native pollination networks can have direct and indirect effects on local plant and pollinator communities. Impacts on local plants are well documented; however effects on native pollinators have gained less attention. We examine these issues in habitat fragments of the endangered oak-savannah ecosystem in British Columbia, Canada. We measured pollen collection by native bumble bees (Bombus Latreille; Hymenoptera: Apidae) and the introduced honey bee (Apis mellifera Linnaeus; Hymenoptera: Apidae) foraging on two common native plants in habitat fragments with varying invasive (Cytisus scoparius (Linnaeus) Link; Fabaceae) density. The Bombus species with the largest workers had higher proportions of invasive pollen on their bodies and in their corbiculae than smaller workers. Honey bees rarely collected C. scoparius pollen. While some native bumble bees species collect an increasing proportion of C. scoparius pollen with increasing C. scoparius density, this did not translate into an increased potential for pollination. Rather, measures of effective pollination decline with C. scoparius density. Overall, our results suggest that some bee species may be better at finding resources at highly invaded sites. Apis mellifera is likely not playing a major role in facilitating the spread of C. scoparius in our region. Rather C. scoparius is visited by a complement of native bumble bees that are similar to pollinators in the native range of this plant.


Author(s):  
Agata Di Noi ◽  
Silvia Casini ◽  
Tommaso Campani ◽  
Giampiero Cai ◽  
Ilaria Caliani

Honey bees and the pollination services they provide are fundamental for agriculture and biodiversity. Agrochemical products and other classes of contaminants, such as trace elements and polycyclic aromatic hydrocarbons, contribute to the general decline of bees’ populations. For this reason, effects, and particularly sublethal effects of contaminants need to be investigated. We conducted a review of the existing literature regarding the type of effects evaluated in Apis mellifera, collecting information about regions, methodological approaches, the type of contaminants, and honey bees’ life stages. Europe and North America are the regions in which A. mellifera biological responses were mostly studied and the most investigated compounds are insecticides. A. mellifera was studied more in the laboratory than in field conditions. Through the observation of the different responses examined, we found that there were several knowledge gaps that should be addressed, particularly within enzymatic and molecular responses, such as those regarding the immune system and genotoxicity. The importance of developing an integrated approach that combines responses at different levels, from molecular to organism and population, needs to be highlighted in order to evaluate the impact of anthropogenic contamination on this pollinator species.


2012 ◽  
Vol 24 (8) ◽  
pp. 1079 ◽  
Author(s):  
Brandon K. Hopkins ◽  
Charles Herr ◽  
Walter S. Sheppard

Much of the world’s food production is dependent on honey bees for pollination, and expanding food production will further increase the demand for managed pollination services. Apiculturists outside the native range of the honey bee, in the Americas, Australia and eastern Asia, have used only a few of the 27 described subspecies of honey bees (Apis mellifera) for beekeeping purposes. Within the endemic ranges of a particular subspecies, hybridisation can threaten native subspecies when local beekeepers import and propagate non-native honey bees. For many threatened species, cryopreserved germplasm can provide a resource for the preservation of diversity and recovery of endangered populations. However, although instrumental insemination of queen honey bees is well established, the absence of an effective means to cryopreserve honey bee semen has limited the success of efforts to preserve genetic diversity within the species or to develop repositories of honey bee germplasm for breeding purposes. Herein we report that some queens inseminated with cryopreserved semen were capable of producing a substantial number of fertilised offspring. These diploid female larvae were used to produce two additional sequential generations of new queens, which were then back-crossed to the same stock of frozen semen. Our results demonstrate the ability to produce queens using cryopreserved honey bee spermatozoa and the potential for the establishment of a honey bee genetic repository.


2021 ◽  
Author(s):  
Amy C Geffre ◽  
Dillon Travis ◽  
Joshua Kohn ◽  
James Nieh

Bees provide critical pollination services but are threatened by multiple stressors, including viral pathogens. Most studies of pollinator health focus on managed honey bees (Apis mellifera Linnaeus) (MHB) or native bee species, but a third player, the feral honey bee (FHB), requires further study. Spillover and spillback of viral pathogens between these managed, feral, and native bees is generating increasing interest. In this case study, we provide evidence suggesting that FHB colonies play an important role in viral pathogen dynamics of southern California pollinator communities because they act as reservoirs, of viral pathogens such as acute bee paralysis virus (ABPV), black queen cell virus (BQCV), and deformed wing virus (DWV). Surprisingly, even though FHB are not treated for diseases or parasites, they harbor similar pathogen loads to MHB, which are usually highly treated, suggesting the need for future studies to determine if FHB resist or are more resilient to viruses.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1993
Author(s):  
Philipp W. Eckerter ◽  
Lars Albus ◽  
Sharumathi Natarajan ◽  
Matthias Albrecht ◽  
Lolita Ammann ◽  
...  

Wild bumblebees are key pollinators of crops and wild plants that rely on the continuous availability of floral resources. A better understanding of the spatio-temporal availability and use of floral food resources may help to promote bumblebees and their pollination services in agricultural landscapes. We placed colonies of Bombus terrestris L. in 24 agricultural landscapes with various degrees of floral resource availability and assessed different parameters of colony growth and fitness. We estimated pollen availability during different periods of colony development based on detailed information of the bumblebee pollen diet and the spatial distribution of the visited plant species. Total pollen availability did not significantly explain colony growth or fitness. However, when using habitat maps, the weight gain of colonies, the number of queen cells, and colony survival decreased with increasing distance from the forest. The better explanation of bumblebee performance by forest proximity than by (plant-inferred) pollen availability indicates that other functions of forests than pollen provision were important. The conservation of forests next to agricultural land might help to sustain high populations of these important wild pollinators and enhance their crop pollination services. Combining different mapping approaches might help to further disentangle complex relationships between B. terrestris and their environment in agricultural landscapes.


2005 ◽  
Vol 137 (4) ◽  
pp. 441-449 ◽  
Author(s):  
Miguel Angel Pinkus-Rendon ◽  
Víctor Parra-Tabla ◽  
Virginia Meléndez-Ramírez

AbstractDespite the importance of native pollinators in agricultural systems, little is known about the potential competitive interactions among them or the way they exploit crops' floral resources. This study determines the temporal use of floral resources by, and interspecific interactions between, native bees and Apis mellifera L. (Hymenoptera: Apidae) in experimental plots of squash, Cucurbita moschata (Duchesne ex Lam.) Duchesne ex Poir. (Cucurbitaceae), and watermelon, Citrullus lanatus (Thunb.) (Cucurbitaceae). General and specific niche overlap analyses were done to determine whether temporally differential use of floral resources occurred. Direct displacement interactions at the floral level were quantified. The species with the greatest abundances were Peponapis limitaris Cockerell (Apidae), Partamona bilineata Say (Apidae), and A. mellifera. Overall, the niche overlap analyses in both crops suggested that floral resources are not used simultaneously by different bee species. Winner events during aggressive encounters suggested a hierarchy among bee species, with A. mellifera being one of the species with more winner encounters in both crops. It is suggested that those deciding whether or not to introduce A. mellifera into crops should consider whether the abundance of native bee species is sufficient to ensure efficient fruit production.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257701
Author(s):  
Gabriela M. Quinlan ◽  
Meghan O. Milbrath ◽  
Clint R. V. Otto ◽  
Rufus Isaacs

Agriculturally important commercially managed pollinators including honey bees (Apis mellifera L., 1758) and bumble bees (Bombus impatiens Cresson, 1863) rely on the surrounding landscape to fulfill their dietary needs. A previous study in Europe demonstrated that managed honey bee foragers and unmanaged native bumble bee foragers are associated with different land uses. However, it is unclear how response to land use compares between managed honey bees and a managed native bumble bee species in the United States, where honey bees are an imported species. Furthermore, to our knowledge, no such direct comparisons of bee responses to land use have been made at the colony level. To better understand how two different social bees respond to variation in land use, we monitored the weights of A. mellifera and B. impatiens colonies placed in 12 apiaries across a range of land use in Michigan, United States in 2017. Bombus impatiens colonies gained more weight and produced more drones when surrounded by diverse agricultural land (i.e., non-corn/soybean cropland such as tree fruits and grapes), while honey bee colonies gained more weight when surrounded by more grassland/pasture land. These findings add to our understanding of how different bee species respond to agricultural landscapes, highlighting the need for further species-specific land use studies to inform tailored land management.


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