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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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Martínez-Martínez CA, Cordeiro GD, Martins HOJ, Kobal ROAC, Milet-Pinheiro P, Stanton MA, Franco EL, Krug C, Mateus S, Schlindwein C, Dötterl S, Alves-dos-Santos I. Floral Volatiles: A Promising Method to Access the Rare Nocturnal and Crepuscular Bees. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.676743] [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
Crepuscular and/or nocturnal bees fly during the dusk, the dawn or part of the night. Due to their short foraging time and sampling bias toward diurnal bees, nocturnal bees are rarely collected and poorly studied. So far, they have been mostly sampled with light and Malaise traps. However, synthetic chemical compounds resembling floral volatiles were recently found to be a promising alternative to attract these bees. By reviewing available literature and collecting original data, we present information on the attraction and sampling of nocturnal bees with scent-baited traps. Bees were actively captured with entomological nets while approaching to filter papers moistened with distinct chemical compound, or passively caught in bottles with scent baits left during the night. So far, all data available are from the Neotropics. Nocturnal bees belonging to three genera, i.e., Ptiloglossa, Megalopta, and Megommation were attracted to at least ten different synthetic compounds and mixtures thereof, identified from bouquets of flowers with nocturnal anthesis. Aromatic compounds, such as 2-phenyletanol, eugenol and methyl salicylate, and the monoterpenoid eucalyptol were the most successful in attracting nocturnal bees. We highlight the effectiveness of olfactory methods to survey crepuscular and nocturnal bees using chemical compounds typically reported as floral scent constituents, and the possibility to record olfactory preferences of each bee species to specific compounds. We suggest to include this method in apifauna surveys in order to improve our current knowledge on the diversity of nocturnal bees in different ecosystems.
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Soares NC, Maruyama PK, Staggemeier VG, Morellato LPC, Araújo MS. The role of individual variation in flowering and pollination in the reproductive success of a crepuscular buzz-pollinated plant. ANNALS OF BOTANY 2021; 127:213-222. [PMID: 32914162 PMCID: PMC7789112 DOI: 10.1093/aob/mcaa163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND AND AIMS Plant individuals within a population differ in their phenology and interactions with pollinators. However, it is still unknown how individual differences affect the reproductive success of plants that have functionally specialized pollination systems. Here, we evaluated whether plant individual specialization in phenology (temporal specialization) and in pollination (pollinator specialization) affect the reproductive success of the crepuscular-bee-pollinated plant Trembleya laniflora (Melastomataceae). METHODS We quantified flowering activity (amplitude, duration and overlap), plant-pollinator interactions (number of flowers visited by pollinators) and reproductive success (fruit set) of T. laniflora individuals from three distinct locations in rupestrian grasslands of southeastern Brazil. We estimated the degree of individual temporal specialization in flowering phenology and of individual specialization in plant-pollinator interactions, and tested their relationship with plant reproductive success. KEY RESULTS Trembleya laniflora presented overlapping flowering, a temporal generalization and specialized pollinator interactions. Flowering overlap among individuals and populations was higher than expected by chance but did not affect the individual interactions with pollinators and nor their reproductive success. In contrast, higher individual generalization in the interactions with pollinators was related to higher individual reproductive success. CONCLUSIONS Our findings suggest that individual generalization in plant-pollinator interaction reduces the potential costs of specialization at the species level, ensuring reproductive success. Altogether, our results highlight the complexity of specialization/generalization of plant-pollinator interactions at distinct levels of organization, from individuals to populations, to species.
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Affiliation(s)
- Natalia Costa Soares
- Laboratório de Fenologia, Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, SP, Brazil
| | - Pietro Kiyoshi Maruyama
- Centro de Síntese Ecológica e Conservação, Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vanessa Graziele Staggemeier
- Laboratório de Fenologia, Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, SP, Brazil
- Departamento de Ecologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Leonor Patrícia Cerdeira Morellato
- Laboratório de Fenologia, Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, SP, Brazil
| | - Márcio Silva Araújo
- Departamento de Biodiversidade, Instituto de Biociências, Universidade Estadual Paulista, Rio Claro, SP, Brazil
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Light intensity regulates flower visitation in Neotropical nocturnal bees. Sci Rep 2020; 10:15333. [PMID: 32948798 PMCID: PMC7501267 DOI: 10.1038/s41598-020-72047-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/12/2020] [Indexed: 11/30/2022] Open
Abstract
The foraging activity of diurnal bees often relies on flower availability, light intensity and temperature. We do not know how nocturnal bees, which fly at night and twilight, cope with these factors, especially as light levels vary considerably from night to day and from night to night due to moon phase and cloud cover. Given that bee apposition compound eyes function at their limits in dim light, we expect a strong dependence of foraging activity on light intensity in nocturnal bees. Besides being limited by minimum light levels to forage, nocturnal bees should also avoid foraging at brighter intensities, which bring increased competition with other bees. We investigated how five factors (light intensity, flower availability, temperature, humidity, and wind) affect flower visitation by Neotropical nocturnal bees in cambuci (Campomanesia phaea, Myrtaceae). We counted visits per minute over 30 nights in 33 cambuci trees. Light intensity was the main variable explaining flower visitation of nocturnal bees, which peaked at intermediate light levels occurring 25 min before sunrise. The minimum light intensity threshold to visit flowers was 0.00024 cd/m2. Our results highlight the dependence of these nocturnal insects on adequate light levels to explore resources.
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Cordeiro GD, Pinheiro M, Dötterl S, Alves-Dos-Santos I. Pollination of Campomanesia phaea (Myrtaceae) by night-active bees: a new nocturnal pollination system mediated by floral scent. PLANT BIOLOGY (STUTTGART, GERMANY) 2017; 19:132-139. [PMID: 27770587 DOI: 10.1111/plb.12520] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/19/2016] [Indexed: 05/27/2023]
Abstract
Bees are the most important diurnal pollinators of angiosperms. In several groups of bees a nocturnal/crepuscular habit developed, yet little is known about their role in pollination and whether some plants are adapted specifically to these bees. We used a multidisciplinary approach to investigate the reproductive biology and to understand the role of nocturnal/crepuscular bees in pollination of Campomanesia phaea (Myrtaceae), popularly named cambuci. We studied the floral biology and breeding system of C. phaea. We collected the floral visitors and tested the pollinators' effectiveness. We also determined the floral scents released at night and during daytime, and studied behavioural responses of crepuscular/nocturnal bees towards these scents. The flowers of cambuci were self-incompatible and had pollen as the only resource for flower visitors. Anthesis lasted around 14 h, beginning at 04:30 h at night. The flowers released 14 volatile compounds, mainly aliphatic and aromatic compounds. We collected 52 species of floral visitors, mainly bees. Nocturnal and crepuscular bees (four species) were among the most frequent species and the only effective pollinators. In field bioassays performed at night, nocturnal/crepuscular bees were attracted by a synthetic scent blend consisting of the six most abundant compounds. This study describes the first scent-mediated pollination system between a plant and its nocturnal bee pollinators. Further, C. phaea has several floral traits that do not allow classification into other nocturnal pollination syndromes (e.g. pollinator attraction already before sunrise, with pollen as the only reward), instead it is a plant specifically adapted to nocturnal bees.
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Affiliation(s)
- G D Cordeiro
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - M Pinheiro
- Universidade Federal da Fronteira Sul, Cerro Largo, Rio Grande do Sul, Brazil
| | - S Dötterl
- Department of Ecology & Evolution, University of Salzburg, Salzburg, Austria
| | - I Alves-Dos-Santos
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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Smith AR, Kitchen SM, Toney RM, Ziegler C. Is Nocturnal Foraging in a Tropical Bee an Escape From Interference Competition? JOURNAL OF INSECT SCIENCE (ONLINE) 2017; 17:3743770. [PMID: 28931157 PMCID: PMC5469389 DOI: 10.1093/jisesa/iex030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 06/07/2023]
Abstract
Temporal niche partitioning may result from interference competition if animals shift their activity patterns to avoid aggressive competitors. If doing so also shifts food sources, it is difficult to distinguish the effects of interference and consumptive competition in selecting for temporal niche shift. Bees compete for pollen and nectar from flowers through both interference and consumptive competition, and some species of bees have evolved nocturnality. Here, we use tropical forest canopy towers to observe bees (the night-flying sweat bees Megalopta genalis and M. centralis [Halictidae], honey bees, and stingless bees [Apidae]) visiting flowers of the balsa tree (Ochroma pyramalidae, Malvaceae). Because Ochroma flowers are open in the late afternoon through the night we can test the relative influence of each competition type on temporal nice. Niche shift due to consumptive competition predicts that Megalopta forage when resources are available: from afternoon into the night. Niche shift due to interference competition predicts that Megalopta forage only in the absence of diurnal bees. We found no overlap between diurnal bees and Megalopta in the evening, and only one instance of overlap in the morning, despite the abundance of pollen and nectar in the late afternoon and evening. This supports the hypothesis that Megalopta are avoiding interference competition, but not the hypothesis that they are limited by consumptive competition. We propose that the release from interference competition enables Megalopta to provision cells quickly, and spend most of their time investing in nest defense. Thus, increases in foraging efficiency directly resulting from temporal shifts to escape interference competition may indirectly lead to reduced predation and parasitism.
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Affiliation(s)
- Adam R. Smith
- Department of Biological Sciences, George Washington University, Washington, DC (; ; )
| | - Shannon M. Kitchen
- Department of Biological Sciences, George Washington University, Washington, DC (; ; )
| | - Ryan M. Toney
- Department of Biological Sciences, George Washington University, Washington, DC (; ; )
| | - Christian Ziegler
- Smithsonian Tropical Research Institute, Luis Clement Ave., Bldg. 401 Tupper, Balboa Ancon, Panama, Republic of Panama ()
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