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Keaveny EC, Helling MR, Basile F, Strange JP, Lozier JD, Dillon ME. Metabolomes of bumble bees reared in common garden conditions suggest constitutive differences in energy and toxin metabolism across populations. JOURNAL OF INSECT PHYSIOLOGY 2023; 151:104581. [PMID: 37871769 DOI: 10.1016/j.jinsphys.2023.104581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 10/19/2023] [Accepted: 10/20/2023] [Indexed: 10/25/2023]
Abstract
Cold tolerance of ectotherms can vary strikingly among species and populations. Variation in cold tolerance can reflect differences in genomes and transcriptomes that confer cellular-level protection from cold; additionally, shifts in protein function and abundance can be altered by other cellular constituents as cold-exposed insects often have shifts in their metabolomes. Even without a cold challenge, insects from different populations may vary in cellular composition that could alter cold tolerance, but investigations of constitutive differences in metabolomes across wild populations remain rare. To address this gap, we reared Bombus vosnesenskii queens collected from Oregon and California (USA) that differ in cold tolerance (CTmin = -6 °C and 0 °C, respectively) in common garden conditions, and measured offspring metabolomes using untargeted LC-MS/MS. Oregon bees had higher levels of metabolites associated with carbohydrate (sorbitol, lactitol, maltitol, and sorbitol-6-phosphate) and amino acid (hydroxyproline, ornithine, and histamine) metabolism. Exogenous metabolites, likely derived from the diet, also varied between Oregon and California bees, suggesting population-level differences in toxin metabolism. Overall, our results reveal constitutive differences in metabolomes for bumble bees reared in common garden conditions from queens collected in different locations despite no previous cold exposure.
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Affiliation(s)
- Ellen C Keaveny
- Department of Zoology and Physiology and Program in Ecology and Evolution, University of Wyoming, Laramie, WY 82071, United States.
| | - Mitchell R Helling
- Department of Chemistry, University of Wyoming, Laramie, WY 82071, United States
| | - Franco Basile
- Department of Chemistry, University of Wyoming, Laramie, WY 82071, United States
| | - James P Strange
- USDA-ARS Pollinating Insects Research Unit, Utah State University, Logan, UT 84322, United States; Department of Entomology, The Ohio State University, Columbus, OH 44691, United States
| | - Jeffrey D Lozier
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, United States
| | - Michael E Dillon
- Department of Zoology and Physiology and Program in Ecology and Evolution, University of Wyoming, Laramie, WY 82071, United States.
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2
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El-Saadi MI, MacMillan HA, Ferguson LV. Cold-induced immune activation in chill-susceptible insects. CURRENT OPINION IN INSECT SCIENCE 2023:101054. [PMID: 37207832 DOI: 10.1016/j.cois.2023.101054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/03/2023] [Accepted: 05/12/2023] [Indexed: 05/21/2023]
Abstract
Chilling injuries in chill-susceptible insects, like the model dipteran Drosophila melanogaster, have been well-documented as a consequence of stressful low temperature exposures. Cold stress also causes upregulation of genes in the insect immune pathways, some of which are also upregulated following other forms of sterile stress. The adaptive significance and underlying mechanisms surrounding cold-induced immune activation, however, are still unclear. Here, we review recent work on the roles of ROS, DAMPs, and AMPs in insect immune signalling or function. Using this emerging knowledge, we propose a conceptual model linking biochemical and molecular causes of immune activation to its consequences during and following cold stress.
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Affiliation(s)
- Mahmoud I El-Saadi
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada, K1S 5B6
| | - Heath A MacMillan
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada, K1S 5B6
| | - Laura V Ferguson
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada, B4P 2R6
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3
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Orlova M, Porter M, Hines HM, Amsalem E. Symptomatic Infection with Vairimorpha spp. Decreases Diapause Survival in a Wild Bumble Bee Species ( Bombus griseocollis). Animals (Basel) 2023; 13:ani13101656. [PMID: 37238086 DOI: 10.3390/ani13101656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/27/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Vairimorpha, a microsporidian parasite (previously classified as Nosema), has been implicated in the decline of wild bumble bee species in North America. Previous studies examining its influence on colony performance have displayed variable results, from extremely detrimental effects to no observable influence, and little is known about the effects it has on individuals during the winter diapause, a bottleneck for survival in many annual pollinators. Here, we examined the effect of Vairimorpha infection, body size, and mass on diapause survival in Bombus griseocollis gynes. We demonstrate that gyne survival length in diapause is negatively affected by symptomatic Vairimorpha infection of the maternal colony but does not correlate with individual pathogen load. Our findings further indicate that increased body mass offers a protective effect against mortality during diapause in infected, but not in healthy, gynes. This suggests that access to adequate nutritional resources prior to diapause might offset the harmful effect of Vairimorpha infection.
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Affiliation(s)
- Margarita Orlova
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biology and Chemistry, College of Arts and Sciences, State University of New York Polytechnic Institute, Utica, NY 13502, USA
| | - Monique Porter
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Heather M Hines
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Etya Amsalem
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802, USA
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4
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Campion C, Rajamohan A, Dillon ME. Sperm can't take the heat: Short-term temperature exposures compromise fertility of male bumble bees (Bombus impatiens). JOURNAL OF INSECT PHYSIOLOGY 2023; 146:104491. [PMID: 36773841 DOI: 10.1016/j.jinsphys.2023.104491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/23/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Bumble bee (genus Bombus) populations are increasingly under threat from habitat fragmentation, pesticides, pathogens, and climate change. Climate change is likely a prime driver of bumble bee declines but the mechanisms by which changing climates alter local abundance, leading to shifts in geographic range are unclear. Heat tolerance is quite high in worker bumble bees (CTmax ∼ 48-55 °C), making it unlikely for them to experience these high temperatures, even with climate warming. However, the thermal tolerance of whole organisms often exceeds that of their gametes; many insects can be sterilized by exposure to temperatures well below their upper thermal tolerance. Male bumble bees are independent from the colony and may encounter more frequent temperature extremes, but whether these exposures compromise spermatozoa is still unclear. Using commercially-reared Bombus impatiens colonies, males were reared in the lab and spermatozoa were exposed (in vivo and isolated in vitro) to sublethal temperatures near lower and upper thermal tolerance (CTmin and CTmax, respectively). Heat exposure (45 °C for up to 85 min) reduced spermatozoa viability both for whole males (in vivo; control = 79.5 %, heat exposed = 58 %, heat stupor = 57.7 %) and isolated seminal vesicles (in vitro; control = 85.5 %, heat exposed = 62.9 %). Whole males exposed to 4 °C for 85 min (in vivo; control = 79.2 %, cold = 72.4 %), isolated seminal vesicles exposed to 4 °C for 85 min (in vitro; control = 85.5 %, cold = 85.1 %), and whole males exposed to for 4 °C for 48 h (in vivo; control = 88.7 %, cold = 84.3 %) did not differ significantly in spermatozoa viability. After<85 min at 45 °C, males had significantly reduced spermatozoa viability, suggesting that short-term heat waves below CTmax could strongly reduce the fertility of male bumble bees with potential population-level impacts.
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Affiliation(s)
- Claire Campion
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
| | - Arun Rajamohan
- Edward T. Schafer Agricultural Research Center, USDA-ARS, 1616 Fargo, ND 58102, USA
| | - Michael E Dillon
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
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5
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Gonzalez VH, Oyen K, Vitale N, Ospina R. Neotropical stingless bees display a strong response in cold tolerance with changes in elevation. CONSERVATION PHYSIOLOGY 2022; 10:coac073. [PMID: 36570736 PMCID: PMC9773376 DOI: 10.1093/conphys/coac073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/25/2022] [Accepted: 11/09/2022] [Indexed: 06/17/2023]
Abstract
Tropical pollinators are expected to experience substantial effects due to climate change, but aspects of their thermal biology remain largely unknown. We investigated the thermal tolerance of stingless honey-making bees, the most ecologically, economically and culturally important group of tropical pollinators. We assessed changes in the lower (CTMin) and upper (CTMax) critical thermal limits of 17 species (12 genera) at two elevations (200 and 1500 m) in the Colombian Andes. In addition, we examined the influence of body size (intertegular distance, ITD), hairiness (thoracic hair length) and coloration (lightness value) on bees' thermal tolerance. Because stingless beekeepers often relocate their colonies across the altitudinal gradient, as an initial attempt to explore potential social responses to climatic variability, we also tracked for several weeks brood temperature and humidity in nests of three species at both elevations. We found that CTMin decreased with elevation while CTMax was similar between elevations. CTMin and CTMax increased (low cold tolerance and high heat tolerance) with increasing ITD, hair length and lightness value, but these relationships were weak and explained at most 10% of the variance. Neither CTMin nor CTMax displayed significant phylogenetic signal. Brood nest temperature tracked ambient diel variations more closely in the low-elevation site, but it was constant and higher at the high-elevation site. In contrast, brood nest humidity was uniform throughout the day regardless of elevation. The stronger response in CTMin, and a similar CTMax between elevations, follows a pattern of variation documented across a wide range of taxa that is commonly known as the Brett's heat-invariant hypothesis. Our results indicate differential thermal sensitivities and potential thermal adaptations to local climate, which support ongoing conservation policies to restrict the long-distance relocations of colonies. They also shed light on how malleable nest thermoregulation can be across elevations.
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Affiliation(s)
- Victor H Gonzalez
- Corresponding author: Undergraduate Biology Program and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA.
| | - Kennan Oyen
- Department of Biological Sciences, McMicken College of Arts and Sciences, University of Cincinnati, 318 College Drive, Cincinnati, OH, 45221, USA
| | - Nydia Vitale
- Instituto Argentino de Investigaciones de las Zonas Áridas, CONICET, Mendoza, 5500, Argentina
| | - Rodulfo Ospina
- Laboratorio de Investigaciones en Abejas, Universidad Nacional de Colombia, Santa Fé de Bogotá, 111321, Colombia
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6
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Fitzgerald JL, Ogilvie JE, CaraDonna PJ. Ecological Drivers and Consequences of Bumble Bee Body Size Variation. ENVIRONMENTAL ENTOMOLOGY 2022; 51:1055-1068. [PMID: 36373400 DOI: 10.1093/ee/nvac093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Indexed: 06/16/2023]
Abstract
Body size is arguably one of the most important traits influencing the physiology and ecology of animals. Shifts in animal body size have been observed in response to climate change, including in bumble bees (Bombus spp. [Hymenoptera: Apidae]). Bumble bee size shifts have occurred concurrently with the precipitous population declines of several species, which appear to be related, in part, to their size. Body size variation is central to the ecology of bumble bees, from their social organization to the pollination services they provide to plants. If bumble bee size is shifted or constrained, there may be consequences for the pollination services they provide and for our ability to predict their responses to global change. Yet, there are still many aspects of the breadth and role of bumble bee body size variation that require more study. To this end, we review the current evidence of the ecological drivers of size variation in bumble bees and the consequences of that variation on bumble bee fitness, foraging, and species interactions. In total we review: (1) the proximate determinants and physiological consequences of size variation in bumble bees; (2) the environmental drivers and ecological consequences of size variation; and (3) synthesize our understanding of size variation in predicting how bumble bees will respond to future changes in climate and land use. As global change intensifies, a better understanding of the factors influencing the size distributions of bumble bees, and the consequences of those distributions, will allow us to better predict future responses of these pollinators.
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Affiliation(s)
- Jacquelyn L Fitzgerald
- Plant Biology and Conservation, Northwestern University, Evanston, IL 60201, USA
- Chicago Botanic Garden, Negaunee Institute for Plant Conservation Science & Action, Glencoe, IL 60022, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | - Jane E Ogilvie
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
| | - Paul J CaraDonna
- Plant Biology and Conservation, Northwestern University, Evanston, IL 60201, USA
- Chicago Botanic Garden, Negaunee Institute for Plant Conservation Science & Action, Glencoe, IL 60022, USA
- Rocky Mountain Biological Laboratory, Crested Butte, CO 81224, USA
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7
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Thermal limits of Africanized honey bees are influenced by temperature ramping rate but not by other experimental conditions. J Therm Biol 2022; 110:103369. [DOI: 10.1016/j.jtherbio.2022.103369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 09/30/2022] [Accepted: 10/06/2022] [Indexed: 11/05/2022]
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Gonzalez VH, Oyen K, Aguilar ML, Herrera A, Martin RD, Ospina R. High thermal tolerance in high-elevation species and laboratory-reared colonies of tropical bumble bees. Ecol Evol 2022; 12:e9560. [PMID: 36479027 PMCID: PMC9720000 DOI: 10.1002/ece3.9560] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 11/07/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
Bumble bees are key pollinators with some species reared in captivity at a commercial scale, but with significant evidence of population declines and with alarming predictions of substantial impacts under climate change scenarios. While studies on the thermal biology of temperate bumble bees are still limited, they are entirely absent from the tropics where the effects of climate change are expected to be greater. Herein, we test whether bees' thermal tolerance decreases with elevation and whether the stable optimal conditions used in laboratory-reared colonies reduces their thermal tolerance. We assessed changes in the lower (CTMin) and upper (CTMax) critical thermal limits of four species at two elevations (2600 and 3600 m) in the Colombian Andes, examined the effect of body size, and evaluated the thermal tolerance of wild-caught and laboratory-reared individuals of Bombus pauloensis. We also compiled information on bumble bees' thermal limits and assessed potential predictors for broadscale patterns of variation. We found that CTMin decreased with increasing elevation, while CTMax was similar between elevations. CTMax was slightly higher (0.84°C) in laboratory-reared than in wild-caught bees while CTMin was similar, and CTMin decreased with increasing body size while CTMax did not. Latitude is a good predictor for CTMin while annual mean temperature, maximum and minimum temperatures of the warmest and coldest months are good predictors for both CTMin and CTMax. The stronger response in CTMin with increasing elevation, and similar CTMax, supports Brett's heat-invariant hypothesis, which has been documented in other taxa. Andean bumble bees appear to be about as heat tolerant as those from temperate areas, suggesting that other aspects besides temperature (e.g., water balance) might be more determinant environmental factors for these species. Laboratory-reared colonies are adequate surrogates for addressing questions on thermal tolerance and global warming impacts.
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Affiliation(s)
- Victor H. Gonzalez
- Undergraduate Biology Program and Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
| | - Kennan Oyen
- Department of Biological Sciences, McMicken College of Arts and SciencesUniversity of CincinnatiCincinnatiOhioUSA
| | | | - Andres Herrera
- Undergraduate Biology Program and Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
| | | | - Rodulfo Ospina
- Laboratorio de Investigaciones en AbejasUniversidad Nacional de ColombiaSanta Fé de BogotáColombia
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9
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Moraiti CA, Verykouki E, Papadopoulos NT. Chill coma recovery of Ceratitis capitata adults across the Northern Hemisphere. Sci Rep 2022; 12:17555. [PMID: 36266456 PMCID: PMC9585097 DOI: 10.1038/s41598-022-21340-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 09/26/2022] [Indexed: 01/13/2023] Open
Abstract
The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is an invasive pest, that is currently expanding its geographic distribution from the Mediterranean coasts to more temperate areas of Europe. Given that low temperature is a primary determinant of insect species' range boundaries especially in the Northern Hemisphere with pronounced seasonality, we used chill coma recovery time for assessing latitudinal clines in basal chill tolerance of C. capitata adults. We selected six populations obtained from areas with broad climatic variability based on the main bioclimatic variables of temperature and precipitation, spanning a latitudinal range of about 19° from Middle East to Central Europe. Adults were exposed to 0 °C for 4 h, and time to regain the typical standing position of a fly at 25 °C were recorded. The post-stress survival after a period of 8 days was also recorded. Results revealed that adults from Israel and Austria were less chill tolerant than those from Greece, resulting in curvilinear trends with latitude. Analysis of macroclimatic conditions revealed combined effects of latitude (as a proxy of photoperiod) and macroclimatic conditions on chill coma recovery time. Nonetheless, there was not a deleterious effect on post-recovery survival, except for flies obtained from the northern most point (Vienna, Austria). Overall, it seems that evolutionary patterns of basal chill coma recovery time of C. capitata adults are driven mainly by local climatic variability.
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Affiliation(s)
- Cleopatra A Moraiti
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, Fytokou St., 38446, Volos, Magnesia, Greece
| | - Eleni Verykouki
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, Fytokou St., 38446, Volos, Magnesia, Greece
| | - Nikos T Papadopoulos
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, School of Agricultural Sciences, University of Thessaly, Fytokou St., 38446, Volos, Magnesia, Greece.
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10
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Roeder KA, Daniels JD. Thermal tolerance of western corn rootworm: Critical thermal limits, knock-down resistance, and chill coma recovery. J Therm Biol 2022; 109:103338. [DOI: 10.1016/j.jtherbio.2022.103338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/02/2022] [Accepted: 09/13/2022] [Indexed: 10/14/2022]
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11
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Keaveny EC, Waybright SA, Rusch TW, Dillon ME. Supercooling points of freeze-avoiding bumble bees vary with caste and queen life stage. J Therm Biol 2022; 104:103196. [PMID: 35180973 DOI: 10.1016/j.jtherbio.2022.103196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/12/2022] [Accepted: 01/21/2022] [Indexed: 11/27/2022]
Abstract
Bumble bees thrive in cold climates including high latitude and high altitude regions around the world, yet cold tolerance strategies are largely unknown for most species. To determine bumble bee cold tolerance strategy, we exposed bumble bees to a range of low temperatures and measured survival 72 h post-exposure. All bees that froze died within 72 h while only one bee died without freezing, suggesting that bumble bees are generally freeze-avoiding insects and may be slightly chill susceptible. We then assessed whether temperatures that cause internal ice formation (supercooling points, SCP) varied among bumble bee castes (drones, workers, and queens), or across queen life stages, collection elevation, species, or season. Males froze at significantly lower temperatures than workers or queens. Queens in pre-overwintering or overwintering states froze at significantly lower temperatures than queens stimulated to initiate ovary development by CO2 narcosis (i.e., "spring" queens). We also tested whether the presence of water (i.e., wet or dry) or ramping rate affected SCP. As expected, queens inoculated with water froze at significantly higher temperatures than dry queens. SCP tended to be lower, but not significantly so, at faster ramping rates (0.5 °C/min vs 0.25 °C/min). We also found no differences in SCP between queen bumble bees collected in spring and fall, between queens collected at two sites differing in elevation by 1100 m, or between three field-caught bumble bee species. Bumble bees appear to have relatively high, invariable SCPs, likely making them highly susceptible to freezing across all seasons. As bumble bees are not freeze-tolerant and appear to lack the ability to prevent freezing at temperatures much below 0 °C, they may rely on season- and caste-specific micro-habitat selection to thrive in cold climates.
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Affiliation(s)
- Ellen C Keaveny
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA.
| | - Sarah A Waybright
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA.
| | - Travis W Rusch
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
| | - Michael E Dillon
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, 82071, USA
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12
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Ghisbain G. Are Bumblebees Relevant Models for Understanding Wild Bee Decline? FRONTIERS IN CONSERVATION SCIENCE 2021. [DOI: 10.3389/fcosc.2021.752213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The unsustainable use of ecosystems by human societies has put global biodiversity in peril. Bees are, in this context, a popular example of a highly diversified group of pollinators whose collapse is a major concern given the invaluable ecosystem services they provide. Amongst them, bumblebees (Bombus) have increasingly drawn the attention of scientists due to their dramatic population declines globally. This regression has converted them into popular conservation entities, making them the second most studied group of bees worldwide. However, in addition to have become relevant models in the fields of ecology, evolution and biogeography, bumblebees have also been used as models for studying wild bee decline and conservation worldwide. Integrating evidence from the comparative ecology and resilience of bumblebees and wild bees, I discuss the relevance of using Bombus as radars for wild bee decline worldwide. Responses of bumblebees to environmental changes are generally not comparable with those of wild bees because of their relatively long activity period, their inherent sensitivity to high temperatures, their relatively generalist diet breadth and many aspects arising from their eusocial behavior. Moreover, important differences in the available historical data between bumblebees and other bees make comparisons of conservation status even more arduous. Overall, these results reinforce the need for conservation actions that consider a higher level of understanding of ecological diversity in wild bees, highlight the need for an updated and more extensive sampling of these organisms, and emphasize that more caution is required when extrapolating trends from model species.
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13
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Przybyla K, Michez D, Zambra E, Anselmo A, Hennebert E, Rasmont P, Martinet B. Effects of Heat Stress on Mating Behavior and Colony Development in Bombus terrestris (Hymenoptera: Apidae). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.748405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Climate change is related to an increase in the frequency and intensity of extreme events such as heatwaves. In insect pollinators, heat exposure is associated with direct physiological perturbations, and in several species, could lead to a decrease of fitness related to a decrease in fertility. Here we developed a new experimental protocol in controlled conditions to assess if the exposure to high temperatures could modify the attractiveness and fertility of Bombus terrestris males. Our results show that virgin queens of B. terrestris do not have preferences between the pheromonal secretions of heat-exposed and control males. Moreover, mating with a heat-exposed male has no impact on the copulation behavior and the development of the nest (brood composition). We advise to extend trials to cover a range of wild and heat-sensitive species on multiple generations to better understand the impact of heat waves on the bumblebee communities.
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