1
|
van der Kooi CJ, Reuvers L, Spaethe J. Honesty, reliability, and information content of floral signals. iScience 2023; 26:107093. [PMID: 37426347 PMCID: PMC10329176 DOI: 10.1016/j.isci.2023.107093] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023] Open
Abstract
Plants advertise their presence by displaying attractive flowers, which pollinators use to locate a floral reward. Understanding how floral traits scale with reward status lies at the heart of pollination biology, because it connects the different interests of plants and pollinators. Studies on plant phenotype-reward associations often use different terms and concepts, which limits developing a broader synthesis. Here, we present a framework with definitions of the key aspects of plant phenotype-reward associations and provide measures to quantify them across different species and studies. We first distinguish between cues and signals, which are often used interchangeably, but have different meanings and are subject to different selective pressures. We then define honesty, reliability, and information content of floral cues/signals and provide ways to quantify them. Finally, we discuss the ecological and evolutionary factors that determine flower phenotype-reward associations, how context-dependent and temporally variable they are, and highlight promising research directions.
Collapse
Affiliation(s)
- Casper J. van der Kooi
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
- Department of Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| | - Lora Reuvers
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| |
Collapse
|
2
|
Howard SR, Symonds MRE. Complex preference relationships between native and non-native angiosperms and foraging insect visitors in a suburban greenspace under field and laboratory conditions. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 2023; 110:16. [PMID: 37140757 PMCID: PMC10160202 DOI: 10.1007/s00114-023-01846-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 03/23/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023]
Abstract
The introduction and spread of non-native flora threatens native pollinators and plants. Non-native angiosperms can compete with native plants for pollinators, space, and other resources which can leave native bees without adequate nutritional or nesting resources, particularly specialist species. In the current study, we conducted flower preference experiments through field observations and controlled binary choice tests in an artificial arena to determine the impact of field vs. laboratory methods on flower preferences of native bees for native or non-native flowers within their foraging range. We conducted counts of insect pollinators foraging on the flowers of three plant species in a suburban green belt including one native (Arthropodium strictum) and two non-native (Arctotheca calendula and Taraxacum officinale) plant species. We then collected native halictid bees foraging on each of the three plant species and conducted controlled binary tests to determine their preferences for the flowers of native or non-native plant species. In the field counts, halictid bees visited the native plant significantly more than the non-native species. However, in the behavioural assays when comparing A. strictum vs. A. calendula, Lasioglossum (Chilalictus) lanarium (Family: Halictidae), bees significantly preferred the non-native species, regardless of their foraging history. When comparing A. strictum vs. T. officinale, bees only showed a preference for the non-native flower when it had been collected foraging on the flowers of that plant species immediately prior to the experiment; otherwise, they showed no flower preference. Our results highlight the influence that non-native angiosperms have on native pollinators and we discuss the complexities of the results and the possible reasons for different flower preferences under laboratory and field conditions.
Collapse
Affiliation(s)
- Scarlett R Howard
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia.
- School of Biological Sciences, Monash University, Clayton, VIC, Australia.
| | - Matthew R E Symonds
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia
| |
Collapse
|
3
|
Baek M, Bish SE, Giebink NW, Papaj DR. The interplay of experience and pre-existing bias in nectar-robbing behavior by the common eastern bumble bee. Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-023-03313-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
|
4
|
Basso-Alves JP, da Silva RF, Coimbra G, Leitão SG, de Rezende CM, Bizzo HR, Freitas L, Paulino JV, Mansano VDF. Heteromorphic stamens are differentially attractive in Swartzia (Fabaceae). AOB PLANTS 2022; 14:plac041. [PMID: 36267642 PMCID: PMC9575666 DOI: 10.1093/aobpla/plac041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
The division of labour hypothesis between stamens has explained the evolution of divergent functions between dimorphic stamens in the same flower. However, little is known about whether the distinct type of stamens differs in attractiveness to pollinators. Therefore, we investigate whether the two types of stamens commonly found in Swartzia have different visual and olfactory attractants. We performed observations of anthesis dynamics, registration and collection of floral visitors, measurements of reflectance of floral parts and chemical analysis of the volatile organic compounds of the floral parts of two species, S. flaemingii and S. simplex. Both species have two distinct sets of stamens: one with smaller and abundant stamens in the centre of the flower and the other with fewer but larger abaxial stamens. The sets differ in UV reflectance (only S. simplex) and exhibit a distinct chromatic contrast. Concerning olfactory attractiveness, aliphatic compounds make up most of the odour of the two species, both whole flowers and most of their floral organs. On the other hand, only S. simplex presented apocarotenoids (as ionones) and benzenoids. Furthermore, there are differences in the proportion of volatiles emitted by the stamen in both cases, as the high proportion of sesquiterpenes among the smaller stamens compared to the larger ones. In conclusion, the two types of stamens found in S. flaemingii and S. simplex show a distinct attractiveness. In addition, our data have demonstrated diverse ways of differential attractiveness both between distinct stamens set per flower and between the two species from the same pollen flowers genus.
Collapse
Affiliation(s)
| | - Rafael Ferreira da Silva
- Departamento de Química Orgânica/GQO, Instituto de Química, Universidade Federal Fluminense (UFF), Niterói, RJ 24020141, Brazil
| | - Gabriel Coimbra
- Programa de Pós-Graduação em Botânica, Escola Nacional de Botânica Tropical, Jardim Botânico do Rio de Janeiro, Rio de Janeiro, RJ 22460-036, Brazil
- Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, DIPEQ-JBRJ, Rio de Janeiro, RJ 22460-030, Brazil
| | - Suzana Guimarães Leitão
- Departamento de Produtos Naturais e Alimentos, Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ 21941-902, Brazil
| | - Claudia Moraes de Rezende
- Instituto de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ 22945970, Brazil
| | | | - Leandro Freitas
- Programa de Pós-Graduação em Botânica, Escola Nacional de Botânica Tropical, Jardim Botânico do Rio de Janeiro, Rio de Janeiro, RJ 22460-036, Brazil
- Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, DIPEQ-JBRJ, Rio de Janeiro, RJ 22460-030, Brazil
| | - Juliana Villela Paulino
- Programa de Pós-Graduação em Botânica, Escola Nacional de Botânica Tropical, Jardim Botânico do Rio de Janeiro, Rio de Janeiro, RJ 22460-036, Brazil
- Departamento de Produtos Naturais e Alimentos, Faculdade de Farmácia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ 21941-902, Brazil
| | | |
Collapse
|
5
|
Howard SR, Dyer AG, Garcia JE, Giurfa M, Reser DH, Rosa MGP, Avarguès-Weber A. Naïve and Experienced Honeybee Foragers Learn Normally Configured Flowers More Easily Than Non-configured or Highly Contrasted Flowers. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.662336] [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
Angiosperms have evolved to attract and/or deter specific pollinators. Flowers provide signals and cues such as scent, colour, size, pattern, and shape, which allow certain pollinators to more easily find and visit the same type of flower. Over evolutionary time, bees and angiosperms have co-evolved resulting in flowers being more attractive to bee vision and preferences, and allowing bees to recognise specific flower traits to make decisions on where to forage. Here we tested whether bees are instinctively tuned to process flower shape by training both flower-experienced and flower-naïve honeybee foragers to discriminate between pictures of two different flower species when images were either normally configured flowers or flowers which were scrambled in terms of spatial configuration. We also tested whether increasing picture contrast, to make flower features more salient, would improve or impair performance. We used four flower conditions: (i) normally configured greyscale flower pictures, (ii) scrambled flower configurations, (iii) high contrast normally configured flowers, and (iv) asymmetrically scrambled flowers. While all flower pictures contained very similar spatial information, both experienced and naïve bees were better able to learn to discriminate between normally configured flowers than between any of the modified versions. Our results suggest that a specialisation in flower recognition in bees is due to a combination of hard-wired neural circuitry and experience-dependent factors.
Collapse
|
6
|
Richman SK, Barker JL, Baek M, Papaj DR, Irwin RE, Bronstein JL. The Sensory and Cognitive Ecology of Nectar Robbing. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.698137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Animals foraging from flowers must assess their environment and make critical decisions about which patches, plants, and flowers to exploit to obtain limiting resources. The cognitive ecology of plant-pollinator interactions explores not only the complex nature of pollinator foraging behavior and decision making, but also how cognition shapes pollination and plant fitness. Floral visitors sometimes depart from what we think of as typical pollinator behavior and instead exploit floral resources by robbing nectar (bypassing the floral opening and instead consuming nectar through holes or perforations made in floral tissue). The impacts of nectar robbing on plant fitness are well-studied; however, there is considerably less understanding, from the animal’s perspective, about the cognitive processes underlying nectar robbing. Examining nectar robbing from the standpoint of animal cognition is important for understanding the evolution of this behavior and its ecological and evolutionary consequences. In this review, we draw on central concepts of foraging ecology and animal cognition to consider nectar robbing behavior either when individuals use robbing as their only foraging strategy or when they switch between robbing and legitimate foraging. We discuss sensory and cognitive biases, learning, and the role of a variable environment in making decisions about robbing vs. foraging legitimately. We also discuss ways in which an understanding of the cognitive processes involved in nectar robbing can address questions about how plant-robber interactions affect patterns of natural selection and floral evolution. We conclude by highlighting future research directions on the sensory and cognitive ecology of nectar robbing.
Collapse
|
7
|
Howard SR, Prendergast K, Symonds MRE, Shrestha M, Dyer AG. Spontaneous choices for insect-pollinated flower shapes by wild non-eusocial halictid bees. J Exp Biol 2021; 224:271069. [PMID: 34318316 DOI: 10.1242/jeb.242457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 07/22/2021] [Indexed: 11/20/2022]
Abstract
The majority of angiosperms require animal pollination for reproduction, and insects are the dominant group of animal pollinators. Bees are considered one of the most important and abundant insect pollinators. Research into bee behaviour and foraging decisions has typically centred on managed eusocial bee species, including Apis mellifera and Bombus terrestris. Non-eusocial bees are understudied with respect to foraging strategies and decision making, such as flower preferences. Understanding whether there are fundamental foraging strategies and preferences that are features of insect groups can provide key insights into the evolution of flower-pollinator co-evolution. In the current study, Lasioglossum (Chilalictus) lanarium and Lasioglossum (Parasphecodes) sp., two native Australian generalist halictid bees, were tested for flower shape preferences between native insect-pollinated and bird-pollinated flowers. Each bee was presented with achromatic images of either insect-pollinated or bird-pollinated flowers in a circular arena. Both native bee species demonstrated a significant preference for images of insect-pollinated flowers. These preferences are similar to those found in A. mellifera, suggesting that flower shape preference may be a deep-rooted evolutionary occurrence within bees. With growing interest in the sensory capabilities of non-eusocial bees as alternative pollinators, the current study also provides a valuable framework for further behavioural testing of such species.
Collapse
Affiliation(s)
- Scarlett R Howard
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Kit Prendergast
- School of Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
| | - Matthew R E Symonds
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Mani Shrestha
- Disturbance Ecology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, 95440 Bayreuth, Germany.,Faculty of Information Technology, Monash University, Clayton, VIC 3800, Australia
| | - Adrian G Dyer
- School of Media and Communication, RMIT University, Melbourne, VIC 3000, Australia.,Department of Physiology, Monash University, Clayton, VIC 3800, Australia
| |
Collapse
|
8
|
Comparative psychophysics of colour preferences in two species of non-eusocial Australian native halictid bees. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2021; 207:657-666. [PMID: 34241711 DOI: 10.1007/s00359-021-01504-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 10/20/2022]
Abstract
Colour signalling by flowers appears to be the main plant-pollinator communication system observed across many diverse species and locations worldwide. Bees are considered one of the most important insect pollinators; however, native non-eusocial bees are often understudied compared to managed eusocial species, such as honeybees and bumblebees. Here, we tested two species of native Australian non-eusocial halictid bees on their colour preferences for seven different broadband colours with bee-colour-space dominant wavelengths ranging from 385 to 560 nm and a neutral grey control. Lasioglossum (Chilalictus) lanarium demonstrated preferences for a UV-absorbing white (455 nm) and a yellow (560 nm) stimulus. Lasioglossum (Parasphecodes) sp. showed no colour preferences. Subsequent analyses showed that green contrast and spectral purity had a significant positive relationship with the number of visits by L. lanarium to stimuli. Colour preferences were consistent with other bee species and may be phylogenetically conserved and linked to how trichromatic bees processes visual information, although the relative dearth of empirical evidence on different bee species currently makes it difficult to dissect mechanisms. Past studies and our current results suggest that both innate and environmental factors might both be at play in mediating bee colour preferences.
Collapse
|
9
|
Howard SR. Wild non-eusocial bees learn a colour discrimination task in response to simulated predation events. Naturwissenschaften 2021; 108:28. [PMID: 34152477 DOI: 10.1007/s00114-021-01739-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/06/2021] [Accepted: 05/31/2021] [Indexed: 02/08/2023]
Abstract
Despite representing the majority of bee species, non-eusocial bees (e.g. solitary, subsocial, semisocial, and quasisocial species) are comparatively understudied in learning, memory, and cognitive-like behaviour compared to eusocial bees, such as honeybees and bumblebees. Ecologically relevant colour discrimination tasks are well-studied in eusocial bees, and research has shown that a few non-eusocial bee species are also capable of colour learning and long-term memory retention. Australia hosts over 2000 native bee species, most of which are non-eusocial, yet evidence of cognitive-like behaviour and learning abilities under controlled testing conditions is lacking. In the current study, I examine the learning ability of a non-eusocial Australian bee, Lasioglossum (Chilalictus) lanarium, using aversive differential conditioning during a colour discrimination task. L. lanarium learnt to discriminate between salient blue- and yellow-coloured stimuli following training with simulated predation events. This study acts as a bridge between cognitive studies on eusocial and non-social bees and introduces a framework for testing non-eusocial wild bees on elemental visual learning tasks using aversive conditioning. Non-eusocial bee species are far more numerous than eusocial species and contribute to agriculture, economics, and ecosystem services in Australia and across the globe. Thus, it is important to study their capacity to learn flower traits allowing for successful foraging and pollination events, thereby permitting us a better understanding of their role in plant-pollinator interactions.
Collapse
Affiliation(s)
- Scarlett R Howard
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC, Australia.
| |
Collapse
|
10
|
Torices R, DeSoto L, Narbona E, Gómez JM, Pannell JR. Effects of the Relatedness of Neighbours on Floral Colour. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.589781] [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
The reproductive success of plants depends both on their phenotype and the local neighbourhood in which they grow. Animal-pollinated plants may benefit from increased visitation when surrounded by attractive conspecific individuals, via a “magnet effect.” Group attractiveness is thus potentially a public good that can be exploited by individuals, with selfish exploitation predicted to depend on genetic relatedness within the group. Petal colour is a potentially costly trait involved in floral signalling and advertising to pollinators. Here, we assessed whether petal colour was plastically sensitive to the relatedness of neighbours in the annual herb Moricandia moricandioides, which produces purple petals through anthocyanin pigment accumulation. We also tested whether petal colour intensity was related to nectar volume and sugar content in a context-dependent manner. Although both petal colour and petal anthocyanin concentration did not significantly vary with the neighbourhood configuration, plants growing with kin made a significantly higher investment in petal anthocyanin pigments as a result of the greater number and larger size of their flowers. Moreover the genetic relatedness of neighbours significantly modified the relationship between floral signalling and reward quantity: while focal plants growing with non-kin showed a positive relationship between petal colour and nectar production, plants growing with kin showed a positive relationship between number of flowers and nectar volume, and sugar content. The observed plastic response to group relatedness might have important effects on pollinator behaviour and visitation, with direct and indirect effects on plant reproductive success and mating patterns, at least in those plant species with patchy and genetically structured populations.
Collapse
|
11
|
Dalrymple RL, Kemp DJ, Flores-Moreno H, Laffan SW, White TE, Hemmings FA, Moles AT. Macroecological patterns in flower colour are shaped by both biotic and abiotic factors. THE NEW PHYTOLOGIST 2020; 228:1972-1985. [PMID: 32533864 DOI: 10.1111/nph.16737] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/24/2020] [Indexed: 05/22/2023]
Abstract
There is a wealth of research on the way interactions with pollinators shape flower traits. However, we have much more to learn about influences of the abiotic environment on flower colour. We combine quantitative flower colour data for 339 species from a broad spatial range covering tropical, temperate, arid, montane and coastal environments from 9.25ºS to 43.75ºS with 11 environmental variables to test hypotheses about how macroecological patterns in flower colouration relate to biotic and abiotic conditions. Both biotic community and abiotic conditions are important in explaining variation of flower colour traits on a broad scale. The diversity of pollinating insects and the plant community have the highest predictive power for flower colouration, followed by mean annual precipitation and solar radiation. On average, flower colours are more chromatic where there are fewer pollinators, solar radiation is high, precipitation and net primary production are low, and growing seasons are short, providing support for the hypothesis that higher chromatic contrast of flower colours may be related to stressful conditions. To fully understand the ecology and evolution of flower colour, we should incorporate the broad selective context that plants experience into research, rather than focusing primarily on effects of plant-pollinator interactions.
Collapse
Affiliation(s)
- Rhiannon L Dalrymple
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Darrell J Kemp
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, North Ryde, Sydney, NSW, 2109, Australia
| | - Habacuc Flores-Moreno
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Shawn W Laffan
- School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Thomas E White
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, Sydney, NSW, 2109, Australia
| | - Frank A Hemmings
- John T. Waterhouse Herbarium, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Angela T Moles
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| |
Collapse
|
12
|
Garcia JE, Phillips RD, Peter CI, Dyer AG. Changing How Biologists View Flowers-Color as a Perception Not a Trait. FRONTIERS IN PLANT SCIENCE 2020; 11:601700. [PMID: 33329670 PMCID: PMC7710862 DOI: 10.3389/fpls.2020.601700] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/23/2020] [Indexed: 05/31/2023]
Abstract
Studying flower color evolution can be challenging as it may require several different areas of expertise, ranging from botany and ecology through to understanding color sensing of insects and thus how they perceive flower signals. Whilst studies often view plant-pollinator interactions from the plant's perspective, there is growing evidence from psychophysics studies that pollinators have their own complex decision making processes depending on their perception of color, viewing conditions and individual experience. Mimicry of rewarding flowers by orchids is a fascinating system for studying the pollinator decision making process, as rewarding model flowering plants and mimics can be clearly characterized. Here, we focus on a system where the rewardless orchid Eulophia zeyheriana mimics the floral color of Wahlenbergia cuspidata (Campanulaceae) to attract its pollinator species, a halictid bee. Using recently developed psychophysics principles, we explore whether the color perception of an insect observer encountering variable model and mimic flower color signals can help explain why species with non-rewarding flowers can exist in nature. Our approach involves the use of color discrimination functions rather than relying on discrimination thresholds, and the use of statistical distributions to model intraspecific color variations. Results show that whilst an experienced insect observer can frequently make accurate discriminations between mimic and rewarding flowers, intraspecific signal variability leads to overlap in the perceived color, which will frequently confuse an inexperienced pollinator. This new perspective provides an improved way to incorporate pollinator decision making into the complex field of plant-pollinator interactions.
Collapse
Affiliation(s)
- Jair E. Garcia
- Bio-Inspired Digital Sensing Laboratory (BIDS Lab), School of Media and Communication, RMIT University, Melbourne, VIC, Australia
| | - Ryan D. Phillips
- Department of Ecology, Environment and Evolution, La Trobe University, Bundoora, VIC, Australia
- Department of Biodiversity, Conservation, and Attractions, Kings Park Science, Perth, WA, Australia
- Department of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Craig I. Peter
- Department of Botany, Rhodes University, Grahamstown, South Africa
| | - Adrian G. Dyer
- Bio-Inspired Digital Sensing Laboratory (BIDS Lab), School of Media and Communication, RMIT University, Melbourne, VIC, Australia
| |
Collapse
|
13
|
Shrestha M, Garcia JE, Burd M, Dyer AG. Australian native flower colours: Does nectar reward drive bee pollinator flower preferences? PLoS One 2020; 15:e0226469. [PMID: 32525873 PMCID: PMC7289428 DOI: 10.1371/journal.pone.0226469] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 05/18/2020] [Indexed: 11/18/2022] Open
Abstract
Colour is an important signal that flowering plants use to attract insect pollinators like bees. Previous research in Germany has shown that nectar volume is higher for flower colours that are innately preferred by European bees, suggesting an important link between colour signals, bee preferences and floral rewards. In Australia, flower colour signals have evolved in parallel to the Northern hemisphere to enable easy discrimination and detection by the phylogenetically ancient trichromatic visual system of bees, and native Australian bees also possess similar innate colour preferences to European bees. We measured 59 spectral signatures from flowers present at two preserved native habitats in South Eastern Australia and tested whether there were any significant differences in the frequency of flowers presenting higher nectar rewards depending upon the colour category of the flower signals, as perceived by bees. We also tested if there was a significant correlation between chromatic contrast and the frequency of flowers presenting higher nectar rewards. For the entire sample, and for subsets excluding species in the Asteraceae and Orchidaceae, we found no significant difference among colour categories in the frequency of high nectar reward. This suggests that whilst such relationships between flower colour signals and nectar volume rewards have been observed at a field site in Germany, the effect is likely to be specific at a community level rather than a broad general principle that has resulted in the common signalling of bee flower colours around the world.
Collapse
Affiliation(s)
- Mani Shrestha
- Bio-Inspired Digital Lab (BIDS-Lab), Schools of Media and Communication, RMIT University, Melbourne, Australia
| | - Jair E. Garcia
- Bio-Inspired Digital Lab (BIDS-Lab), Schools of Media and Communication, RMIT University, Melbourne, Australia
| | - Martin Burd
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Adrian G. Dyer
- Bio-Inspired Digital Lab (BIDS-Lab), Schools of Media and Communication, RMIT University, Melbourne, Australia
- * E-mail:
| |
Collapse
|
14
|
Esmaile N, Rodrigues D. Attractiveness to highly informative flowers and absence of conditioning in the southern monarch butterfly. Behav Processes 2020; 175:104120. [DOI: 10.1016/j.beproc.2020.104120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/27/2020] [Accepted: 03/27/2020] [Indexed: 11/30/2022]
|
15
|
Howard SR, Schramme J, Garcia JE, Ng L, Avarguès-Weber A, Greentree AD, Dyer AG. Spontaneous quantity discrimination of artificial flowers by foraging honeybees. J Exp Biol 2020; 223:223/9/jeb223610. [DOI: 10.1242/jeb.223610] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 04/07/2020] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Many animals need to process numerical and quantity information in order to survive. Spontaneous quantity discrimination allows differentiation between two or more quantities without reinforcement or prior training on any numerical task. It is useful for assessing food resources, aggressive interactions, predator avoidance and prey choice. Honeybees have previously demonstrated landmark counting, quantity matching, use of numerical rules, quantity discrimination and arithmetic, but have not been tested for spontaneous quantity discrimination. In bees, spontaneous quantity discrimination could be useful when assessing the quantity of flowers available in a patch and thus maximizing foraging efficiency. In the current study, we assessed the spontaneous quantity discrimination behaviour of honeybees. Bees were trained to associate a single yellow artificial flower with sucrose. Bees were then tested for their ability to discriminate between 13 different quantity comparisons of artificial flowers (numeric ratio range: 0.08–0.8). Bees significantly preferred the higher quantity only in comparisons where ‘1’ was the lower quantity and where there was a sufficient magnitudinal distance between quantities (e.g. 1 versus 12, 1 versus 4, and 1 versus 3 but not 1 versus 2). Our results suggest a possible evolutionary benefit to choosing a foraging patch with a higher quantity of flowers when resources are scarce.
Collapse
Affiliation(s)
- Scarlett R. Howard
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Jürgen Schramme
- Institute of Developmental Biology and Neurobiology (iDN), Johannes Gutenberg University, Mainz 55122, Germany
| | - Jair E. Garcia
- Bio-inspired Digital Sensing (BIDS) Lab, School of Media and Communication, RMIT University, Melbourne, VIC 3000, Australia
| | - Leslie Ng
- School of BioSciences, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Aurore Avarguès-Weber
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse 31000, France
| | - Andrew D. Greentree
- ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, VIC 3000, Australia
| | - Adrian G. Dyer
- Bio-inspired Digital Sensing (BIDS) Lab, School of Media and Communication, RMIT University, Melbourne, VIC 3000, Australia
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
| |
Collapse
|
16
|
Koethe S, Fischbach V, Banysch S, Reinartz L, Hrncir M, Lunau K. A Comparative Study of Food Source Selection in Stingless Bees and Honeybees: Scent Marks, Location, or Color. FRONTIERS IN PLANT SCIENCE 2020; 11:516. [PMID: 32435253 PMCID: PMC7218124 DOI: 10.3389/fpls.2020.00516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
In social bees, the choice of food sources is based on several factors, including scent marks, color, and location of flowers. Here, we used similar setups, in which two stingless bee species, Melipona subnitida and Plebeia flavocincta, and the Western honeybee, Apis mellifera, were tested regarding the importance of chemical cues, color cues, and location-dependent cues for foraging behavior. It was determined whether workers chose food sources according to (1) scent marks deposited by conspecifics, (2) the color hue of a food source, (3) the trained location or the proximity of a food source to the hive. All three species preferred the scent-marked over an unmarked feeder that was presented simultaneously, but M. subnitida showed a weaker preference compared to the other species. When trained to blue feeders all three bee species preferred blue, but A. mellifera showed the strongest fidelity. The training to yellow feeders led to less distinct color choices. Only workers of M. subnitida mostly orientated at the training position and the close proximity to the nest. Whether the distance of a feeding site influenced the choice was dependent on the tested parameter (color or scent marks) and the species. Workers of M. subnitida preferably visited the feeder closer to the nest during the scent mark trials, but choose randomly when tested for color learning. Worker honeybees preferred the closer feeding site if trained to yellow, but not if trained to blue, and preferred the more distant feeder during the scent mark trials. Workers of P. flavocincta preferred the closer feeder if trained to blue or yellow, and preferred the more distant feeder during the scent mark trials. The disparity among the species corresponds to differences in body size. Smaller bees are known for reduced visual capabilities and might rely less on visual parameters of the target such as color hue, saturation, or brightness but use scent cues instead. Moreover, the dim-light conditions in forest habitats might reduce the reliability of visual orientation as compared to olfactory orientation. Honeybees showed the most pronounced orientation at floral color cues.
Collapse
Affiliation(s)
- Sebastian Koethe
- Institute of Sensory Ecology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Vivian Fischbach
- Institute of Sensory Ecology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sarah Banysch
- Institute of Sensory Ecology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Lara Reinartz
- Institute of Sensory Ecology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Michael Hrncir
- Departamento de Biociências, Universidade Federal Rural do Semi-Árido, Mossoró, Brazil
- Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Klaus Lunau
- Institute of Sensory Ecology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| |
Collapse
|
17
|
Babiychuk E, Teixeira JG, Tyski L, Guimaraes JTF, Romeiro LA, da Silva EF, Dos Santos JF, Vasconcelos S, da Silva DF, Castilho A, Siqueira JO, Fonseca VLI, Kushnir S. Geography is essential for reproductive isolation between florally diversified morning glory species from Amazon canga savannahs. Sci Rep 2019; 9:18052. [PMID: 31792228 PMCID: PMC6889514 DOI: 10.1038/s41598-019-53853-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 11/06/2019] [Indexed: 11/29/2022] Open
Abstract
The variety, relative importance and eco-evolutionary stability of reproductive barriers are critical to understanding the processes of speciation and species persistence. Here we evaluated the strength of the biotic prezygotic and postzygotic isolation barriers between closely related morning glory species from Amazon canga savannahs. The flower geometry and flower visitor assemblage analyses supported pollination by the bees in lavender-flowered Ipomoea marabaensis and recruitment of hummingbirds as pollinators in red-flowered Ipomoea cavalcantei. Nevertheless, native bee species and alien honeybees foraged on flowers of both species. Real-time interspecific hybridization underscored functionality of the overlap in flower visitor assemblages, questioning the strength of prezygotic isolation underpinned by diversification in flower colour and geometry. Interspecific hybrids were fertile and produced offspring in nature. No significant asymmetry in interspecific hybridization and hybrid incompatibilities among offspring were found, indicating weak postmating and postzygotic isolation. The results suggested that despite floral diversification, the insular-type geographic isolation remains a major barrier to gene flow. Findings set a framework for the future analysis of contemporary evolution of plant-pollinator networks at the population, community, and ecosystem levels in tropical ecosystems that are known to be distinct from the more familiar temperate climate models.
Collapse
Affiliation(s)
- Elena Babiychuk
- Instituto Tecnológico Vale, Rua Boaventura da Silva 955, CEP 66055-090, Belém, Pará, Brazil.
| | | | - Lourival Tyski
- Parque Zoobotânico Vale, VALE S.A., Rod. Raimundo Mascarenhas, Km 26, S/N., Núcleo Urbano de Carajás, CEP 68516-000, Parauapebas, Pará, Brazil
| | | | - Luiza Araújo Romeiro
- Instituto Tecnológico Vale, Rua Boaventura da Silva 955, CEP 66055-090, Belém, Pará, Brazil
| | | | | | - Santelmo Vasconcelos
- Instituto Tecnológico Vale, Rua Boaventura da Silva 955, CEP 66055-090, Belém, Pará, Brazil
| | - Delmo Fonseca da Silva
- Parque Zoobotânico Vale, VALE S.A., Rod. Raimundo Mascarenhas, Km 26, S/N., Núcleo Urbano de Carajás, CEP 68516-000, Parauapebas, Pará, Brazil
| | - Alexandre Castilho
- Gerência de Meio Ambiente, Departamento de Ferrosos Corredor Norte, Vale S.A., Rua Guamá n 60, Núcleo Urbano, CEP 68516-000, Parauapebas, Pará, Brazil
| | - José Oswaldo Siqueira
- Instituto Tecnológico Vale, Rua Boaventura da Silva 955, CEP 66055-090, Belém, Pará, Brazil
| | | | - Sergei Kushnir
- Unaffiliated, Belém, Pará, Brazil.,Teagasc, Crop Science Department, Oak Park, Carlow, R93 XE12, Ireland
| |
Collapse
|
18
|
Baracchi D. Cognitive ecology of pollinators and the main determinants of foraging plasticity. Curr Zool 2019; 65:421-424. [PMID: 31423133 PMCID: PMC6688568 DOI: 10.1093/cz/zoz036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- David Baracchi
- Dipartimento di Biologia, Università degli Studi di Firenze, Via Madonna del Piano, 6, Sesto Fiorentino, Firenze, 50019, Italy
| |
Collapse
|
19
|
Hannah L, Dyer AG, Garcia JE, Dorin A, Burd M. Psychophysics of the hoverfly: categorical or continuous color discrimination? Curr Zool 2019; 65:483-492. [PMID: 31413720 PMCID: PMC6688577 DOI: 10.1093/cz/zoz008] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/26/2019] [Indexed: 12/12/2022] Open
Abstract
There is increasing interest in flies as potentially important pollinators. Flies are known to have a complex visual system, including 4 spectral classes of photoreceptors that contribute to the perception of color. Our current understanding of how color signals are perceived by flies is based on data for the blowfly Lucilia sp., which after being conditioned to rewarded monochromatic light stimuli, showed evidence of a categorical color visual system. The resulting opponent fly color space has 4 distinct categories, and has been used to interpret how some fly pollinators may perceive flower colors. However, formal proof that flower flies (Syrphidae) only use a simple, categorical color process remains outstanding. In free-flying experiments, we tested the hoverfly Eristalis tenax, a Batesian mimic of the honeybee, that receives its nutrition by visiting flowers. Using a range of broadband similar–dissimilar color stimuli previously used to test color perception in pollinating hymenopteran species, we evaluated if there are steep changes in behavioral choices with continuously increasing color differences as might be expected by categorical color processing. Our data revealed that color choices by the hoverfly are mediated by a continuous monotonic function. Thus, these flies did not use a categorical processing, but showed evidence of a color discrimination function similar to that observed in several bee species. We therefore empirically provide data for the minimum color distance that can be discriminated by hoverflies in fly color space, enabling an improved understanding of plant–pollinator interactions with a non-model insect species.
Collapse
Affiliation(s)
- Lea Hannah
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia.,Hawkesbury Institute for the Environment, Western Sydney University, Richmond, New South Wales 2753, Australia
| | - Adrian G Dyer
- School of Media and Communication, RMIT University, Melbourne, Victoria 3001, Australia.,Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Jair E Garcia
- School of Media and Communication, RMIT University, Melbourne, Victoria 3001, Australia
| | - Alan Dorin
- Faculty of Information Technology, Monash University, Clayton, Victoria 3800, Australia
| | - Martin Burd
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|