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Gonzalez VH, Herbison N, Robles Perez G, Panganiban T, Haefner L, Tscheulin T, Petanidou T, Hranitz J. Bees display limited acclimation capacity for heat tolerance. Biol Open 2024; 13:bio060179. [PMID: 38427330 PMCID: PMC10979511 DOI: 10.1242/bio.060179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/28/2024] [Indexed: 03/02/2024] Open
Abstract
Bees are essential pollinators and understanding their ability to cope with extreme temperature changes is crucial for predicting their resilience to climate change, but studies are limited. We measured the response of the critical thermal maximum (CTMax) to short-term acclimation in foragers of six bee species from the Greek island of Lesvos, which differ in body size, nesting habit, and level of sociality. We calculated the acclimation response ratio as a metric to assess acclimation capacity and tested whether bees' acclimation capacity was influenced by body size and/or CTMax. We also assessed whether CTMax increases following acute heat exposure simulating a heat wave. Average estimate of CTMax varied among species and increased with body size but did not significantly shift in response to acclimation treatment except in the sweat bee Lasioglossum malachurum. Acclimation capacity averaged 9% among species and it was not significantly associated with body size or CTMax. Similarly, the average CTMax did not increase following acute heat exposure. These results indicate that bees might have limited capacity to enhance heat tolerance via acclimation or in response to prior heat exposure, rendering them physiologically sensitive to rapid temperature changes during extreme weather events. These findings reinforce the idea that insects, like other ectotherms, generally express weak plasticity in CTMax, underscoring the critical role of behavioral thermoregulation for avoidance of extreme temperatures. Conserving and restoring native vegetation can provide bees temporary thermal refuges during extreme weather events.
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Affiliation(s)
- Victor H. Gonzalez
- Undergraduate Biology Program and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA
| | - Natalie Herbison
- Undergraduate Biology Program and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA
| | | | - Trisha Panganiban
- Department of Biological Sciences, California State University, Los Angeles, CA, 35229, USA
| | - Laura Haefner
- Biology Department, Waynesburg University, PA, 47243, USA
| | - Thomas Tscheulin
- Laboratory of Biogeography and Ecology, Department of Geography, University of the Aegean, University Hill, Mytilene, 81100, Greece
| | - Theodora Petanidou
- Laboratory of Biogeography and Ecology, Department of Geography, University of the Aegean, University Hill, Mytilene, 81100, Greece
| | - John Hranitz
- Department of Biology, Commonwealth University of Pennsylvania, Bloomsburg, 17815 PA, USA
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Gonzalez VH, Manweiler R, Smith AR, Oyen K, Cardona D, Wcislo WT. Low heat tolerance and high desiccation resistance in nocturnal bees and the implications for nocturnal pollination under climate change. Sci Rep 2023; 13:22320. [PMID: 38102400 PMCID: PMC10724170 DOI: 10.1038/s41598-023-49815-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023] Open
Abstract
Predicting insect responses to climate change is essential for preserving ecosystem services and biodiversity. Due to high daytime temperatures and low humidity levels, nocturnal insects are expected to have lower heat and desiccation tolerance compared to diurnal species. We estimated the lower (CTMin) and upper (CTMax) thermal limits of Megalopta, a group of neotropical, forest-dwelling bees. We calculated warming tolerance (WT) as a metric to assess vulnerability to global warming and measured survival rates during simulated heatwaves and desiccation stress events. We also assessed the impact of body size and reproductive status (ovary area) on bees' thermal limits. Megalopta displayed lower CTMin, CTMax, and WTs than diurnal bees (stingless bees, orchid bees, and carpenter bees), but exhibited similar mortality during simulated heatwave and higher desiccation tolerance. CTMin increased with increasing body size across all bees but decreased with increasing body size and ovary area in Megalopta, suggesting a reproductive cost or differences in thermal environments. CTMax did not increase with increasing body size or ovary area. These results indicate a greater sensitivity of Megalopta to temperature than humidity and reinforce the idea that nocturnal insects are thermally constrained, which might threaten pollination services in nocturnal contexts during global warming.
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Affiliation(s)
- Victor H Gonzalez
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA.
| | - Rachel Manweiler
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA
| | - Adam R Smith
- Department of Biological Sciences, George Washington University, Washington, District of Columbia, USA
| | - Kennan Oyen
- Animal Disease Research Unit, Agricultural Research Service, United States Department of Agriculture, Pullman, WA, 99164, USA
| | - David Cardona
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - William T Wcislo
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
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White SA, Dillon ME. Climate warming and bumble bee declines: the need to consider sub-lethal heat, carry-over effects, and colony compensation. Front Physiol 2023; 14:1251235. [PMID: 38028807 PMCID: PMC10644220 DOI: 10.3389/fphys.2023.1251235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Global declines in abundance and diversity of insects are now well-documented and increasingly concerning given the critical and diverse roles insects play in all ecosystems. Habitat loss, invasive species, and anthropogenic chemicals are all clearly detrimental to insect populations, but mounting evidence implicates climate change as a key driver of insect declines globally. Warming temperatures combined with increased variability may expose organisms to extreme heat that exceeds tolerance, potentially driving local extirpations. In this context, heat tolerance limits (e.g., critical thermal maximum, CTmax) have been measured for many invertebrates and are often closely linked to climate regions where animals are found. However, temperatures well below CTmax may also have pronounced effects on insects, but have been relatively less studied. Additionally, many insects with out-sized ecological and economic footprints are colonial (e.g., ants, social bees, termites) such that effects of heat on individuals may propagate through or be compensated by the colony. For colonial organisms, measuring direct effects on individuals may therefore reveal little about population-level impacts of changing climates. Here, we use bumble bees (genus Bombus) as a case study to highlight how a limited understanding of heat effects below CTmax and of colonial impacts and responses both likely hinder our ability to explain past and predict future climate change impacts. Insights from bumble bees suggest that, for diverse invertebrates, predicting climate change impacts will require a more nuanced understanding of the effects of heat exposure and additional studies of carry-over effects and compensatory responses by colonies.
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Affiliation(s)
- Sabrina A. White
- Department of Zoology and Physiology and Program in Ecology, University of Wyoming, Laramie, WY, United States
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Bretzlaff T, Kerr JT, Darveau CA. High temperature sensitivity of bumblebee castes and the colony-level costs of thermoregulation in Bombus impatiens. J Therm Biol 2023; 117:103710. [PMID: 37716225 DOI: 10.1016/j.jtherbio.2023.103710] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 09/02/2023] [Accepted: 09/03/2023] [Indexed: 09/18/2023]
Abstract
Physiological thermal limits often reflect species distribution, but the role that ambient temperature (Ta) plays in limiting species within their thermal environment remains unclear. Climate change-linked declines in bumblebees, an important pollinator group, leave questions regarding which aspect of their physiology is hindered under high Ta. As a eusocial species, bumblebees utilize their ability to thermoregulate as a superorganism to maintain nest temperature (Tn) within a narrow thermal window to buffer developing larvae from developmental defects. Thermoregulatory behaviours, such as thermogenesis to warm up and fanning to cool down the nest, are energetically expensive and it is uncertain how successful large colonies are at maintaining Tn within its optimal range. Using a common bumblebee species, Bombus impatiens, our study first established the critical thermal limits (CTmax) of workers, queens, drones and larvae to determine which caste is most thermally sensitive to heat. We found that larvae had significantly lower heat tolerance than adults, highlighting the importance of colonial thermoregulation. We then measured the energy expenditure of large colonies under acute thermal stress (5-40 °C) using flow-through respirometry while simultaneously quantifying Tn. Colonies that experienced Ta at or below optimal Tn (≤30 °C) were successful at thermoregulation. At 35 °C and above, however, Tn increased despite high energetic costs to the colony. Together our results demonstrate that high Ta poses a risk to colonies that fail to buffer thermally sensitive larvae from changes in Tn.
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Affiliation(s)
- Tiffany Bretzlaff
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
| | - Jeremy T Kerr
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
| | - Charles-A Darveau
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, K1N 6N5, Canada.
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Baudier KM, Ostwald MM, Haney BR, Calixto JM, Cossio FJ, Fewell JH. Social Factors in Heat Survival: Multiqueen Desert Ant Colonies Have Higher and More Uniform Heat Tolerance. Physiol Biochem Zool 2022; 95:379-389. [PMID: 35914287 DOI: 10.1086/721251] [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] [Indexed: 11/03/2022]
Abstract
AbstractInvestigations of thermally adaptive behavioral phenotypes are critical for both understanding climate as a selective force and predicting global species distributions under climate change conditions. Cooperative nest founding is a common strategy in harsh environments for many species and can enhance growth and competitive advantage, but whether this social strategy has direct effects on thermal tolerance was previously unknown. We examined the effects of alternative social strategies on thermal tolerance in a facultatively polygynous (multiqueen) desert ant, Pogonomyrmex californicus, asking whether and how queen number affects worker thermal tolerances. We established and reared lab colonies with one to four queens, then quantified all colony member heat tolerances (maximum critical temperature [CTmax]). Workers from colonies with more queens had higher and less variant CTmax. Our findings resemble weak link patterns, in which colony group thermal performance is improved by reducing frequencies of the most temperature-vulnerable individuals. Using ambient temperatures from our collection site, we show that multiqueen colonies have thermal tolerance distributions that enable increased midday foraging in hot desert environments. Our results suggest advantages to polygyny under climate change scenarios and raise the question of whether improved thermal tolerance is a factor that has enabled the success of polygyne species in other climatically extreme environments.
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Thermal physiology, foraging pattern, and worker body size interact to influence coexistence in sympatric polymorphic harvester ants (Messor spp.). Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03186-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Baudier KM, Pavlic TP. Multi-level instrumentation of bivouac thermoregulation: current methods and future directions. ARTIFICIAL LIFE AND ROBOTICS 2022. [DOI: 10.1007/s10015-022-00759-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Nascimento G, Câmara T, Arnan X. Critical thermal limits in ants and their implications under climate change. Biol Rev Camb Philos Soc 2022; 97:1287-1305. [PMID: 35174946 DOI: 10.1111/brv.12843] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 11/28/2022]
Abstract
Critical thermal limits (CTLs) constrain the performance of organisms, shaping their abundance, current distributions, and future distributions. Consequently, CTLs may also determine the quality of ecosystem services as well as organismal and ecosystem vulnerability to climate change. As some of the most ubiquitous animals in terrestrial ecosystems, ants are important members of ecological communities. In recent years, an increasing body of research has explored ant physiological thermal limits. However, these CTL data tend to centre on a few species and biogeographical regions. To encourage an expansion of perspectives, we herein review the factors that determine ant CTLs and examine their effects on present and future species distributions and ecosystem processes. Special emphasis is placed on the implications of CTLs for safeguarding ant diversity and ant-mediated ecosystem services in the future. First, we compile, quantify, and categorise studies on ant CTLs based on study taxon, biogeographical region, methodology, and study question. Second, we use this comprehensive database to analyse the abiotic and biotic factors shaping ant CTLs. Our results highlight how CTLs may affect future distribution patterns and ecological performance in ants. Additionally, we identify the greatest remaining gaps in knowledge and create a research roadmap to promote rapid advances in this field of study.
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Affiliation(s)
- Geraldo Nascimento
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil
| | - Talita Câmara
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil
| | - Xavier Arnan
- Universidade de Pernambuco - Campus Garanhuns, Rua Capitão Pedro Rodrigues, 105 - São José, Garanhuns, 55294-902, Brazil.,Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, Universidade de Pernambuco - Campus Petrolina, BR 203, KM 2 - Vila Eduardo, Petrolina, 56328-900, Brazil.,CREAF, Campus de Bellaterra (UAB) Edifici C, Cerdanyola del Vallès, 08193, Spain
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Perez R, Aron S. Adaptations to thermal stress in social insects: recent advances and future directions. Biol Rev Camb Philos Soc 2020; 95:1535-1553. [PMID: 33021060 DOI: 10.1111/brv.12628] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/20/2023]
Abstract
Thermal stress is a major driver of population declines and extinctions. Shifts in thermal regimes create new environmental conditions, leading to trait adaptation, population migration, and/or species extinction. Extensive research has examined thermal adaptations in terrestrial arthropods. However, little is known about social insects, despite their major role in ecosystems. It is only within the last few years that the adaptations of social insects to thermal stress have received attention. Herein, we discuss what is currently known about thermal tolerance and thermal adaptation in social insects - namely ants, termites, social bees, and social wasps. We describe the behavioural, morphological, physiological, and molecular adaptations that social insects have evolved to cope with thermal stress. We examine individual and collective responses to both temporary and persistent changes in thermal conditions and explore the extent to which individuals can exploit genetic variability to acclimatise. Finally, we consider the costs and benefits of sociality in the face of thermal stress, and we propose some future research directions that should advance our knowledge of individual and collective thermal adaptations in social insects.
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Affiliation(s)
- Rémy Perez
- Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium
| | - Serge Aron
- Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium
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Baudier KM, O’Donnell S. Rain shadow effects predict population differences in thermal tolerance of leaf‐cutting ant workers (
Atta cephalotes
). Biotropica 2019. [DOI: 10.1111/btp.12733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Kaitlin M. Baudier
- School of Life Sciences Arizona State University Tempe Arizona
- Departments of Biodiversity Earth & Environmental Science and Biology Drexel University Philadelphia Pennsylvania
| | - Sean O’Donnell
- Departments of Biodiversity Earth & Environmental Science and Biology Drexel University Philadelphia Pennsylvania
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Manfredini F, Arbetman M, Toth AL. A Potential Role for Phenotypic Plasticity in Invasions and Declines of Social Insects. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00375] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Baudier K, O'Donnell S. Complex body size differences in thermal tolerance among army ant workers (Eciton burchellii parvispinum). J Therm Biol 2018; 78:277-280. [PMID: 30509648 DOI: 10.1016/j.jtherbio.2018.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/05/2018] [Accepted: 10/13/2018] [Indexed: 12/12/2022]
Abstract
In social insects, group members can differ in thermal physiology, and these differences may affect colony function. Upper thermal tolerance limits (CTmax) generally increase with body size among and within ant species, but size effects on lower thermal tolerances (CTmin) are poorly known. To test whether CTmin co-variation with body size matched patterns for CTmax, we measured CTmax and CTmin in workers of four size-based worker subcastes in the army ant Eciton burchellii parvispinum. CTmax increased with worker body size as expected. CTmin showed a more complex relationship with size: the two intermediate-size subcastes (media and porters) tolerated lower temperatures than the smallest (minims) and the largest (soldiers) worker subcastes. Body-size effects on CTmax were not predictive of body-size effects on CTmin. These patterns held for colonies collected across elevations that spanned approximately 8 °C in mean annual temperature, even though high-elevation colonies had significantly lower CTmin overall. We predict Eciton army ant subcastes will be differentially affected by directional changes in high and low temperature extremes. Worker subcastes perform distinct but complementary roles in colony function, and differential temperature effects among subcastes could impair colony performance and negatively impact colony fitness.
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Affiliation(s)
| | - Sean O'Donnell
- Biodiversity Earth & Environmental Science and Biology, Drexel University, USA.
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Baudier KM, D’Amelio CL, Malhotra R, O’Connor MP, O’Donnell S. Extreme Insolation: Climatic Variation Shapes the Evolution of Thermal Tolerance at Multiple Scales. Am Nat 2018; 192:347-359. [DOI: 10.1086/698656] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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