1
|
Hemingway CT, Leonard AS, MacNeill FT, Pimplikar S, Muth F. Pollinator cognition and the function of complex rewards. Trends Ecol Evol 2024:S0169-5347(24)00146-0. [PMID: 39019730 DOI: 10.1016/j.tree.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 06/10/2024] [Accepted: 06/14/2024] [Indexed: 07/19/2024]
Abstract
The cognitive ecology of pollination is most often studied using simple rewards, yet flowers often contain multiple types of chemically complex rewards, each varying along multiple dimensions of quality. In this review we highlight ways in which reward complexity can impact pollinator cognition, demonstrating the need to consider ecologically realistic rewards to fully understand plant-pollinator interactions. We show that pollinators' reward preferences can be modulated by reward chemistry and the collection of multiple reward types. We also discuss how reward complexity can mediate pollinator learning through a variety of mechanisms, both with and without reward preference being altered. Finally, we show how an understanding of decision-making strategies is necessary to predict how pollinators' evaluation of reward options depends on the other options available.
Collapse
Affiliation(s)
- Claire T Hemingway
- Department of Ecology & Evolutionary Biology, Dabney Hall, 1416 Circle Dr., University of Tennessee, Knoxville, TN 37996, USA; Department of Psychology, Austin Peay, 1404 Circle Dr., University of Tennessee, Knoxville, TN 37996, USA; Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA.
| | - Anne S Leonard
- Department of Biology, 1664 North Virginia St, Mailstop 314, University of Nevada, Reno, NV 89557, USA
| | - Fiona Tiley MacNeill
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA
| | - Smruti Pimplikar
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA
| | - Felicity Muth
- Department of Integrative Biology, 2415 Speedway, University of Texas at Austin, Austin, TX 78712, USA; Department of Neurobiology, Physiology, and Behavior, 196 Briggs Hall, University of California, Davis, CA 95616, USA
| |
Collapse
|
2
|
Eltz T, Mende T, Ramírez SR. Evolution of Acquired Perfumes and Endogenous Lipid Secretions in Orchid Bees. J Chem Ecol 2024:10.1007/s10886-024-01514-w. [PMID: 38958679 DOI: 10.1007/s10886-024-01514-w] [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: 12/15/2023] [Revised: 05/16/2024] [Accepted: 05/18/2024] [Indexed: 07/04/2024]
Abstract
Male orchid bees are unique in the animal kingdom for making perfumes that function as sex pheromone. Males collect volatile chemicals from the environment in the neotropical forests, including floral and non-floral sources, creating complex but species-specific blends. Male orchid bees exhibit several adaptations to facilitate perfume collection and storage. When collecting volatile compounds, males apply lipid substances that they secrete from cephalic labial glands onto the fragrant substrate. These lipids help dissolve and retain the volatiles, similar to the process of 'enfleurage' in the traditional perfume industry. We investigated how the chemical composition of acquired perfume and labial gland secretions varied across the phylogeny of orchid bees, including 65 species in five genera from Central and South America. Perfumes showed rapid evolution as revealed by low overall phylogenetic signal, in agreement with the idea that perfume compounds diverge rapidly and substantially among closely related species due to their role in species recognition. A possible exception were perfumes in the genus Eulaema, clustering closely in chemospace, partly mediated by high proportions of carvone and trans-carvone oxide. Labial gland secretions, in contrast, showed a strong phylogenetic signal at the genus level, with secretions of Eufriesea and Exaerete dominated by fatty acids and Eulaema dominated by saturated acetates of chain lengths 12 to 16 C-atoms. Secretions of the majority of Euglossa were heavily dominated by one unsaturated long chain diacetate, (9Z)-Eicosen-1,20-diyldiacetate. However, we also identified few highly divergent species of Euglossa in four subclades (11 species) that appear to have secondarily replaced the diacetate with other compounds. In comparison with environment-derived perfumes, the evolution of labial gland secretion is much slower, likely constrained by the underlying biochemical pathways, but perhaps influenced by perfume-solvent chemical interactions.
Collapse
Affiliation(s)
- Thomas Eltz
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, 44801, Bochum, NRW, Germany.
| | - Tobias Mende
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, 44801, Bochum, NRW, Germany
| | - Santiago R Ramírez
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, CA, 95616, USA
| |
Collapse
|
3
|
Patt JM, Makagon A, Norton B, Marvit M, Rutschman P, Neligeorge M, Salesin J. An optical system to detect, surveil, and kill flying insect vectors of human and crop pathogens. Sci Rep 2024; 14:8174. [PMID: 38589427 PMCID: PMC11002038 DOI: 10.1038/s41598-024-57804-6] [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: 09/14/2023] [Accepted: 03/21/2024] [Indexed: 04/10/2024] Open
Abstract
Sustainable and effective means to control flying insect vectors are critically needed, especially with widespread insecticide resistance and global climate change. Understanding and controlling vectors requires accurate information about their movement and activity, which is often lacking. The Photonic Fence (PF) is an optical system that uses machine vision, infrared light, and lasers to identify, track, and interdict vectors in flight. The PF examines an insect's outline, flight speed, and other flight parameters and if these match those of a targeted vector species, then a low-power, retina-safe laser kills it. We report on proof-of-concept tests of a large, field-sized PF (30 mL × 3 mH) conducted with Aedes aegypti, a mosquito that transmits dangerous arboviruses, and Diaphorina citri, a psyllid which transmits the fatal huanglongbing disease of citrus. In tests with the laser engaged, < 1% and 3% of A. aegypti and D. citri, respectfully, were recovered versus a 38% and 19% recovery when the lacer was silenced. The PF tracked, but did not intercept the orchid bee, Euglossa dilemma. The system effectively intercepted flying vectors, but not bees, at a distance of 30 m, heralding the use of photonic energy, rather than chemicals, to control flying vectors.
Collapse
Affiliation(s)
- Joseph M Patt
- United States Department of Agriculture, Agricultural Research Service, Fort Pierce, FL, 34945, USA.
| | - Arty Makagon
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| | - Bryan Norton
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| | - Maclen Marvit
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| | - Phillip Rutschman
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| | - Matt Neligeorge
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| | - Jeremy Salesin
- Global Health Labs (Formerly Global Good Fund I, LLC), Bellevue, WA, 98007, USA
| |
Collapse
|
4
|
Palmera-Castrillon K, Junqueira CN, Toci AT, Augusto SC. Complexity of the Male Perfume of Eulaema nigrita from Forest and Woody Physiognomies of the Brazilian Savanna: Is There a Relationship with Body Size and Wing Wear? NEOTROPICAL ENTOMOLOGY 2024; 53:330-341. [PMID: 38228817 DOI: 10.1007/s13744-023-01117-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 12/06/2023] [Indexed: 01/18/2024]
Abstract
Male orchid bees collect volatile and semi-volatile compounds from the environment for storage and accumulation in specialized hind legs. Later, these compounds form a perfume blend used during courtship to lure conspecific females for mating. Male orchid bees perfume has been suggested to play an important role as a sexual signaling trait involved in pre-mating isolation of species, functioning as an indicator of male genetic quality. Eulaema nigrita Lepeletier (Apidae: Euglossini) is a common species in both forested and woody savanna (Cerrado stricto sensu) physiognomies of the Brazilian savanna biome. By identifying the chemical composition of male E. nigrita perfume, we tested for differences in the bouquet chemical profile in populations from remnants of seasonal semideciduous forest and woody savanna. In addition, we assessed the relation between perfume complexity and morphological traits associated with size and age of males. Our analysis showed a low effect of physiognomies on differences in the perfume chemical profile of sampled males. Nevertheless, we observed significant differences in the chemical profile of individuals from two seasonal semideciduous forest remnants, which suggests an environmental effect in individual bouquet. Wing wear measurements were positively related to perfume complexity, consistent with the premise that perfumes from older individuals are indicators of survival capacity in male orchid bees.
Collapse
Affiliation(s)
- Kevin Palmera-Castrillon
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Depto de Biologia, Univ de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Aline Theodoro Toci
- Instituto Latino-Americano de Ciências da Vida E da Natureza, Univ Federal da Integração Latino-Americana, Foz Do Iguaçu, Paraná, Brazil
| | | |
Collapse
|
5
|
Henske J, Eltz T. Age-dependent perfume development in male orchid bees, Euglossa imperialis. J Exp Biol 2024; 227:jeb246995. [PMID: 38511547 PMCID: PMC11006377 DOI: 10.1242/jeb.246995] [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: 11/06/2023] [Accepted: 02/24/2024] [Indexed: 03/22/2024]
Abstract
Male neotropical orchid bees concoct complex perfume blends by collecting exogenous volatiles from various sources, including orchids. These perfumes, stored in specialized hind-leg pouches and released during courtship, serve as inter-sexual signals. It has been hypothesized that male perfumes honestly indicate aspects of male fitness. If perfume traits such as quantity or complexity increase over individual lifetime, perfumes could reflect age (survival) and cumulative foraging success of males. We conducted a two-season mark-recapture study with Euglossa imperialis in Costa Rica, monitoring the balance of perfume uptake and expenditure over individual male lifetime. We sealed one hind-leg pouch upon initial capture, 'freezing' the perfume status on one side, and compared it with the other side at recapture to assess changes in perfume traits over time. Additionally, we used a novel method to estimate individual age by combining two parameters of wing degradation. Contrary to predictions, young to intermediate-aged bees had the highest quantities of perfume and the highest diversity of detected compounds. At the same time, the change in perfume between recaptures was positive (increase in amount and complexity) in young bees, whereas it was neutral to negative in older bees. Although these findings do not disprove an indicator function of male perfume, they shift the emphasis to non-cumulative fitness components such as sensory acuteness or cognitive capacity as likely targets of selection. Females preferring strong perfume signals in mates would maximize speed of foraging in offspring rather than their lifetime cumulative yield.
Collapse
Affiliation(s)
- Jonas Henske
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Thomas Eltz
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr-Universität Bochum, 44801 Bochum, Germany
| |
Collapse
|
6
|
Jarrett BJM, Miller CW. Host Plant Effects on Sexual Selection Dynamics in Phytophagous Insects. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:41-57. [PMID: 37562047 DOI: 10.1146/annurev-ento-022823-020258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Natural selection is notoriously dynamic in nature, and so, too, is sexual selection. The interactions between phytophagous insects and their host plants have provided valuable insights into the many ways in which ecological factors can influence sexual selection. In this review, we highlight recent discoveries and provide guidance for future work in this area. Importantly, host plants can affect both the agents of sexual selection (e.g., mate choice and male-male competition) and the traits under selection (e.g., ornaments and weapons). Furthermore, in our rapidly changing world, insects now routinely encounter new potential host plants. The process of adaptation to a new host may be hindered or accelerated by sexual selection, and the unexplored evolutionary trajectories that emerge from these dynamics are relevant to pest management and insect conservation strategies. Examining the effects of host plants on sexual selection has the potential to advance our fundamental understanding of sexual conflict, host range evolution, and speciation, with relevance across taxa.
Collapse
Affiliation(s)
- Benjamin J M Jarrett
- School of Natural Sciences, Bangor University, Bangor, United Kingdom;
- Department of Biology, Lund University, Lund, Sweden
- Department of Entomology and Nematology, University of Florida, Gainesville, Florida, USA;
| | - Christine W Miller
- Department of Entomology and Nematology, University of Florida, Gainesville, Florida, USA;
| |
Collapse
|
7
|
Ayasse M. Chemical ecology: Male orchid bees attract females with environmental-derived perfumes in courtship display. Curr Biol 2023; 33:R405-R407. [PMID: 37220732 DOI: 10.1016/j.cub.2023.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Are male orchid bees the 'chemical peacocks' of the insect world? A new study on orchid bees shows that perfumes of males do indeed have a comparable function as a peacock's tail to increase male mating success and paternity.
Collapse
Affiliation(s)
- Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation Genomics, Ulm University, Albert-Einstein Allee 11, D-89081 Ulm, Germany.
| |
Collapse
|
8
|
Better than Chanel: perfumed male bees draw more mates. Nature 2023; 616:414. [PMID: 37045963 DOI: 10.1038/d41586-023-01033-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
|