1
|
Diaz C, Long JH. Behavior and Bioadhesives: How Bolas Spiders, Mastophora hutchinsoni, Catch Moths. INSECTS 2022; 13:insects13121166. [PMID: 36555076 PMCID: PMC9780859 DOI: 10.3390/insects13121166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 05/12/2023]
Abstract
Spiders use various combinations of silks, adhesives, and behaviors to ensnare and trap prey. A common but difficult to catch prey in most spider habitats are moths. They easily escape typical orb-webs because their bodies are covered in sacrificial scales that flake off when in contact with the web's adhesives. This defense is defeated by spiders of the sub-family of Cyrtarachninae, moth-catching specialists who combine changes in orb-web structure, predatory behavior, and chemistry of the aggregate glue placed in those webs. The most extreme changes in web structure are shown by bolas spiders, who create a solitary capture strand containing only one or two glue droplets at the end of a single thread. They prey on male moths by releasing pheromones to draw them within range of their bolas, which they flick to ensnare the moth. We used a high-speed video camera to capture the behavior of the bolas spider Mastophora hutchinsoni. We calculated the kinematics of spiders and moths in the wild to model the physical and mechanical properties of the bolas during prey capture, the behavior of the moth, and how these factors lead to successful prey capture. We created a numerical model to explain the mechanical behavior of the bolas silk during prey capture. Our kinematic analysis shows that the material properties of the aggregate glue bolas of M. hutchinsoni are distinct from that of the other previously analyzed moth-specialist, Cyrtarachne akirai. The spring-like behavior of the M. hutchinsoni bolas suggests it spins a thicker liquid.
Collapse
|
2
|
Dahake A, Jain P, Vogt CC, Kandalaft W, Stroock AD, Raguso RA. A signal-like role for floral humidity in a nocturnal pollination system. Nat Commun 2022; 13:7773. [PMID: 36522313 PMCID: PMC9755274 DOI: 10.1038/s41467-022-35353-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022] Open
Abstract
Previous studies have considered floral humidity to be an inadvertent consequence of nectar evaporation, which could be exploited as a cue by nectar-seeking pollinators. By contrast, our interdisciplinary study of a night-blooming flower, Datura wrightii, and its hawkmoth pollinator, Manduca sexta, reveals that floral relative humidity acts as a mutually beneficial signal in this system. The distinction between cue- and signal-based functions is illustrated by three experimental findings. First, floral humidity gradients in Datura are nearly ten-fold greater than those reported for other species, and result from active (stomatal conductance) rather than passive (nectar evaporation) processes. These humidity gradients are sustained in the face of wind and are reconstituted within seconds of moth visitation, implying substantial physiological costs to these desert plants. Second, the water balance costs in Datura are compensated through increased visitation by Manduca moths, with concomitant increases in pollen export. We show that moths are innately attracted to humid flowers, even when floral humidity and nectar rewards are experimentally decoupled. Moreover, moths can track minute changes in humidity via antennal hygrosensory sensilla but fail to do so when these sensilla are experimentally occluded. Third, their preference for humid flowers benefits hawkmoths by reducing the energetic costs of flower handling during nectar foraging. Taken together, these findings suggest that floral humidity may function as a signal mediating the final stages of floral choice by hawkmoths, complementing the attractive functions of visual and olfactory signals beyond the floral threshold in this nocturnal plant-pollinator system.
Collapse
Affiliation(s)
- Ajinkya Dahake
- grid.5386.8000000041936877XDepartment of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 USA
| | - Piyush Jain
- grid.5386.8000000041936877XSibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853 USA
| | - Caleb C. Vogt
- grid.5386.8000000041936877XDepartment of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 USA
| | - William Kandalaft
- grid.5386.8000000041936877XDepartment of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 USA
| | - Abraham D. Stroock
- grid.5386.8000000041936877XSmith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853 USA
| | - Robert A. Raguso
- grid.5386.8000000041936877XDepartment of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853 USA
| |
Collapse
|
3
|
Balbuena MS, Broadhead GT, Dahake A, Barnett E, Vergara M, Skogen KA, Jogesh T, Raguso RA. Mutualism has its limits: consequences of asymmetric interactions between a well-defended plant and its herbivorous pollinator. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210166. [PMID: 35491593 DOI: 10.1098/rstb.2021.0166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Concern for pollinator health often focuses on social bees and their agricultural importance at the expense of other pollinators and their ecosystem services. When pollinating herbivores use the same plants as nectar sources and larval hosts, ecological conflicts emerge for both parties, as the pollinator's services are mitigated by herbivory and its larvae are harmed by plant defences. We tracked individual-level metrics of pollinator health-growth, survivorship, fecundity-across the life cycle of a pollinating herbivore, the common hawkmoth, Hyles lineata, interacting with a rare plant, Oenothera harringtonii, that is polymorphic for the common floral volatile (R)-(-)-linalool. Linalool had no impact on floral attraction, but its experimental addition suppressed oviposition on plants lacking linalool. Plants showed robust resistance against herbivory from leaf-disc to whole-plant scales, through poor larval growth and survivorship. Higher larval performance on other Oenothera species indicates that constitutive herbivore resistance by O. harringtonii is not a genus-wide trait. Leaf volatiles differed among populations of O. harringtonii but were not induced by larval herbivory. Similarly, elagitannins and other phenolics varied among plant tissues but were not herbivore-induced. Our findings highlight asymmetric plant-pollinator interactions and the importance of third parties, including alternative larval host plants, in maintaining pollinator health. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
Collapse
Affiliation(s)
- Maria Sol Balbuena
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET, Universidad de Buenos Aires, C1428EHA, Argentina
| | - Geoffrey T Broadhead
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
| | - Ajinkya Dahake
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
| | - Emily Barnett
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Melissa Vergara
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Krissa A Skogen
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL 60035, USA
| | - Tania Jogesh
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA.,Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL 60035, USA
| | - Robert A Raguso
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
4
|
Harrap MJM, Rands SA. The role of petal transpiration in floral humidity generation. PLANTA 2022; 255:78. [PMID: 35246754 PMCID: PMC8897325 DOI: 10.1007/s00425-022-03864-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/22/2022] [Indexed: 05/11/2023]
Abstract
Using petrolatum gel as an antitranspirant on the flowers of California poppy and giant bindweed, we show that transpiration provides a large contribution to floral humidity generation. Floral humidity, an area of elevated humidity in the headspace of flowers, is believed to be produced predominantly through a combination of evaporation of liquid nectar and transpirational water loss from the flower. However, the role of transpiration in floral humidity generation has not been directly tested and is largely inferred by continued humidity production when nectar is removed from flowers. We test whether transpiration contributes to the floral humidity generation of two species previously identified to produce elevated floral humidity, Calystegia silvatica and Eschscholzia californica. Floral humidity production of flowers that underwent an antitranspirant treatment, petrolatum gel which blocks transpiration from treated tissues, is compared to flowers that did not receive such treatments. Gel treatments reduced floral humidity production to approximately a third of that produced by untreated flowers in C. silvatica, and half of that in E. californica. This confirms the previously untested inferences that transpiration has a large contribution to floral humidity generation and that this contribution may vary between species.
Collapse
Affiliation(s)
- Michael J M Harrap
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
- The John Krebs Field Station, University of Oxford, Wytham, Oxford, OX2 8QJ, UK.
| | - Sean A Rands
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK.
| |
Collapse
|
5
|
Harrap MJM, Hempel de Ibarra N, Knowles HD, Whitney HM, Rands SA. Bumblebees can detect floral humidity. J Exp Biol 2021; 224:jeb240861. [PMID: 34161560 PMCID: PMC8246344 DOI: 10.1242/jeb.240861] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 05/10/2021] [Indexed: 11/20/2022]
Abstract
Floral humidity, a region of elevated humidity in the headspace of the flower, occurs in many plant species and may add to their multimodal floral displays. So far, the ability to detect and respond to floral humidity cues has been only established for hawkmoths when they locate and extract nectar while hovering in front of some moth-pollinated flowers. To test whether floral humidity can be used by other more widespread generalist pollinators, we designed artificial flowers that presented biologically relevant levels of humidity similar to those shown by flowering plants. Bumblebees showed a spontaneous preference for flowers that produced higher floral humidity. Furthermore, learning experiments showed that bumblebees are able to use differences in floral humidity to distinguish between rewarding and non-rewarding flowers. Our results indicate that bumblebees are sensitive to different levels of floral humidity. In this way floral humidity can add to the information provided by flowers and could impact pollinator behaviour more significantly than previously thought.
Collapse
Affiliation(s)
- Michael J. M. Harrap
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
- Centre for Research in Animal Behaviour, School of Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Natalie Hempel de Ibarra
- Centre for Research in Animal Behaviour, School of Psychology, University of Exeter, Exeter, EX4 4QG, UK
| | - Henry D. Knowles
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
- Natural Resources Wales, Maes Newydd, Llandarcy, Neath Port Talbot, SA10 6JQ, UK
| | - Heather M. Whitney
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Sean A. Rands
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| |
Collapse
|
6
|
Wolfin MS, Chilson RR, Thrall J, Liu Y, Volo S, Cha DH, Loeb GM, Linn CE. Proximate Mechanisms of Host Plant Location by a Specialist Phytophagous Insect, the Grape Berry Moth, Paralobesia Viteana. J Chem Ecol 2019; 45:946-958. [PMID: 31755018 DOI: 10.1007/s10886-019-01112-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 09/12/2019] [Accepted: 10/03/2019] [Indexed: 12/01/2022]
Abstract
There are contrasting hypotheses regarding the role of plant volatiles in host plant location. We used the grape berry moth (GBM; Paralobesia viteana)-grape plant (Vitis spp.) complex as a model for studying the proximate mechanisms of long distance olfactory-mediated, host-plant location and selection by a specialist phytophagous insect. We used flight tunnel assays to observe GBM female in-flight responses to host (V. riparia) and non-host (apple, Malus domestica; and gray dogwood, Cornus racimosa,) odor sources in the form of plant shoots, extracts of shoots, and synthetic blends. Gas chromatography-electroantennographic detection and gas chromatography/mass spectrometry analyses were used to identify antennal-active volatile compounds. All antennal-active compounds found in grape shoots were also present in dogwood and apple shoots. Female GBM flew upwind to host and non-host extracts and synthetic blends at similar levels, suggesting discrimination is not occurring at long distance from the plant. Further, females did not land on sources releasing plant extracts and synthetic blends, suggesting not all landing cues were present. Additionally, mated and unmated moths displayed similar levels of upwind flight responses to all odor sources, supporting the idea that plant volatiles are not functioning solely as ovipositional cues. The results of this study support a hypothesis that GBM females are using volatile blends to locate a favorable habitat rather than a specific host plant, and that discrimination is occurring within the habitat, or even post-landing.
Collapse
Affiliation(s)
- Michael S Wolfin
- Department of Entomology, Cornell AgriTech at the New York Agricultural Experiment Station, Cornell University, Geneva, NY, USA. .,Department of Entomology, Pennsylvania State University, State College, PA, USA.
| | - Ronald R Chilson
- Department of Entomology, Cornell AgriTech at the New York Agricultural Experiment Station, Cornell University, Geneva, NY, USA
| | - Jonathan Thrall
- Biology Department, Hobart and William Smith Colleges, Geneva, NY, USA
| | - Yuxi Liu
- Biology Department, Hobart and William Smith Colleges, Geneva, NY, USA
| | - Sara Volo
- Biology Department, Hobart and William Smith Colleges, Geneva, NY, USA
| | - Dong H Cha
- USDA-ARS, Daniel K. Inouye US Pacific Basin Agricultural Research Center, Hilo, HI, USA
| | - Gregory M Loeb
- Department of Entomology, Cornell AgriTech at the New York Agricultural Experiment Station, Cornell University, Geneva, NY, USA
| | - Charles E Linn
- Department of Entomology, Cornell AgriTech at the New York Agricultural Experiment Station, Cornell University, Geneva, NY, USA
| |
Collapse
|