7.1 Prey deception in australian crab spiders  (Page 7/7)

Discussion questions:

1. What are some other examples of effective prey deception in animals? How are these examples similar and different to the that of the Australian crab spiders?
2. What would you expect to be evolutionary more advantageous for the Australian crab spider: to become better at signal interception or to change their prey capturing method?
3. The flowers discussed in this chapter rely on honeybees to pollinate them in order to propagate the species. As honeybees become increasingly aware of a spider’s presence on a flower and therefore choose not to visit it, a flower is less likely to pass its genes on to the next generation (Brechbühl, Rolf et al, 2010). What are the evolutionary implications for the flowers? What adaptions could the flower make to increase its likelihood of being pollinated?

Glossary:

• Araneae - spiders; air-breathing chelicerate arthropods with eight legs and venom-injecting fang
• bilateral symmetry - symmetry about one, and only one, plane (called the sagittal plane); bilateral flowers are known as zygomorphic
• coevolutionary arms race - competition between two co-evolving genes that develop adaptations in reaction to adaptations of the other based on a positive feedback model
• crypsis - the ability of an organism to avoid observation
• hymenoptera - one of the largest orders of insects, comprising of wasps, bees, sawflies, termites and ants
• ligulate florets - tongue-shaped petals
• actory - of or relating to the sense of smell
• positive feedback - an effect causes more of itself, an augmentation
• radial symmetry - symmetry about an axis; radial flowers are known as actinomorphic
• tactile - of or relating to the sense of touch
• ultraviolet - electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays (10 nm to 400 nm)

References:

• Aronsson, Marianne and Gabriella Gamberale-Stille. 2009a. Importance of internal pattern contrast and contrast against the background in aposematic signals. Behavioral Ecology. 1-7.

  This study looks at the relation between internal pattern contrast versus contrast of prey against a background using domesticated chicks. The chicks were shown prey that was plain or striped, but neither yielded the significant avoidance results in comparison to contrast against the background.

• Bhaskara, Ramachandra M., C. M. Brijesh, Saveer Ahmed, and Renee M. Borges. 2009a. Perception of ultraviolet light by crab spiders and its role in selection of hunting sites. Journal of Computational Physiology. 195:409-417.

  This article demonstrates that crab spiders (Thomisidae) are able to perceive UV light and use it to become more attractive to prey, thus enhancing their ability to capture honeybees. The crab spiders use Spathiphyllum plants.

• Brechbühl, Rolf, Christian Kropf and Sven Bacher. 2009a. Impact of flower-dwelling crab spiders on plant-pollinator mutualisms. Basic and Applied Ecology. 1-7.

  This article explores the indirect effects of the spider crab preying behavior on the plants where they act. This study demonstrates that the crab spider praying behavior can negatively effect the fitness of the plant species, but primarily when the pollinators of the plants (ie honeybees) are specialized to avoid crab spider occupied plants.

• Brechbühl, Rolf, Jéröme Casas and Sven Bacher. 2010a. Ineffective crypsis in a crab spider: a prey community perspective. Proceedings of the Royal Society of Biological Sciences. 277:739-746.

  Crypsis is the ability to avoid observation. It is a reasonable assumption to presume that predators that can avoid being recognized by their prey would have an advantage. In this study, however, it is shown that flowers with spiders on them are not visited more frequently than others. This demonstrates an indifference to predators, and in order to make sense of these findings, the authors of the paper suggest a community understanding approach.

• Briscoe, AD and Lars Chittka. 2001. The evolution of colour vision in insects. Annual Review of Entomology. 46:471-510.

  A review of the physiological, molecular, and neural mechanisms of insect color vision.

• Chittka, L. 1996. Optimal sets of colour receptors and opponent processes for coding of natural objects in insect vision. J Theoretical Biology. 181:179-196.
• Chittka, L. 2001. Camouflage of predatory crab spiders on flowers and the colour perception of bees. Entomol Gen. 25:181-187.
• Chittka, L and R Menzel. 1992. The evolutionary adaption of flower colours and the insect pollinators’ colour vision. J Comp Physiol A. 171:171-181.
• Chittka, L, A Shmida, N Troje, and R Menzel. 1994. Ultraviolet as a component of flower reflections, and the colour perception of hymenoptera. Vision Res. 34:1489-1508.

  Study shows that flowers colours fall into distinct clusters as viewed by bees. The article purposes a system of colours and naming.

• Chittka, Lars and Nigel E Raine. 2006a. Recognition of flowers by pollinators. Current Opinion in Plant Biology. 9:428-435.

  This article explains the evolution of signal designs by plants to pollinators. It focuses on both visual and olfactory information processing.

• "Crab-spiders manipulate flower signals." Nature 421 (2003): 334. Nature Publishing Group. Web. www.nature.com/nature .

  This is a brief communication summary of a Heiling et. al study about pollinator attraction in Nature.

• Dimitrova, Marina and Sami Merilaita. 2009a. Prey concealment: visual background complexity and prey contrast distribution. Behavioral Ecology. 176-181.

  This study is concerned with the use of camouflage and disruptive coloration by species to avoid predation. In the study, the background of the prey was manipulated and was found to aide in the concealment of prey. Visually complex backgrounds may provide prey with decreased predation risks.

• Giurfa, M, J Núñez, L Chittka, and R Menzel. 1995. Colour preference of flower-naive honeybees. J Comp Physiol A. 177:247-259.
• Guo, Wei and Yildirim Aktas. 2009a. Backaction of a detector on the field it measures. Optics Communications. 282:14-17.

  This article provides insight into the mechanisms of light scattering between a detector and a medium. It can be used in the understanding of how a crab spiders UV contrast mechanism works.

• Heiling, A. M. and M. E. Herberstein. 2004a. Predator-Prey Coevolution: Australian Native Bees Avoid Their Spider Predators. Proceedings of the Royal Society of Biological Sciences. 271:S196-S198.

  This study compares the pollinating behavior of Australian honeybees and non-native honeybees on plants that are occupied by Australian crab spiders Thomisus spectabilis . Native bees approached spider occupied flowers more frequently, however landed on vacant flowers more frequently. The non-native bees did not show this anti-predatory response.

• Heiling, Astrid M., Ken Cheng, and Marie E. Herberstein. 2004a. Exploitation of floral signals by crab spiders ( Thomisus spectabilis , Thomisidae). Behavioral Ecology. 15:321-326.

  This study looked at potential signals to both crab spiders and honeybees to be attracted to a certain flower. The study found that honeybees use olfactory signals, which the spiders exploit to encounter prey.

• Heiling, Astrid M., Ken Cheng, and Marie E. Herberstein. 2006. Picking the right spot: crab spiders position themselves on flowers to maximize prey attraction. Behavioral Ecology. 143:957-968.

  Position of the spider on a plant is important in prey attraction, such that spiders must sit on the petals and not a daisy’s center.

• Heiling, Astrid M., Ken Cheng, Lars Chittka, Ann Goeth and Marie E. Herberstein. 2005a. The role of UV in crab spider signals: effects on perception by prey and predators. The Journal of Experimental Biology. 208:3925-3931.

  In this study, the researchers took crab spiders, typically a UV+ species, and applied an UV-absorbing surface to the insects, creating a UV- spider. This is turn translated into less attraction by honeybees, thus changing the behavior of the prey.

• Heiling, Astrid M., Lars Chittka, Ken Cheng and Marie E. Herberstein. 2005a. Colouration in crab spiders: substrate choice and prey attraction. The Journal of Experimental Biology. 208:1785-1792.

  This study combine observance of honeybee behavior and state-of-the-art knowledge about bee color vision to evaluate honeybee preferences for both white and yellow spiders on both white and yellow plants. The results showed that crab spiders select flowers adaptively in a way that attracts them to their flower, or minimally does not deter them from pollinating it.

• Herberstein, M. E., A. M. Heiling and K. Cheng. 2009a. Evidence for UV-based sensory exploitation in Australian but not European crab spiders. Evolutionary Ecology. 23:621-634.

  This study looks at UV-reflection in crab spiders, which is common in Australian species, but absent in their European counterparts. It is unknown as to whether or not UV-reflection evolved in Australia or whether UV-reflective spiders are more recent arrivals to the continent.

• Hoese, F.J., E.A.J. Law, D. Rao and M.E. Herberstein. 2006a. Distinctive yellow bands on a sit-and-wait predator: prey attractant or camouflage? Behavior. 143:763-781.

  Another example of crypsis in spiders. Spiders with yellow bands on their backs attracted more insects to their web than those with their yellow bands covered by black marker. This indicates that the yellow serves some purpose, whether it be camouflage through disruptive coloration or attractiveness to insects, and thus they are able to attract more prey.

• Pasteur, Georges. 1982a. A Classificatory Review of Mimicry Systems. Ann. Rev. Ecol. Syst. 13:169-99.

  The purpose of this article is to give a definitive and comprehensive review of the types of mimicry systems known to biologists at the time. Special attention is given to semantics.

• Reader, Tom, Andrew D. Higginson, Christopher J. Barnard, Francis S. Gilbert, and The Behavioral Ecology Field Course. 2006a. The effects of predation risk from crab spiders on bee foraging behavior. Behavioral Ecology. 933-939.

  This study evaluated bee reactions to crab spider presence on plants. The study found that plant-pollinator systems were not immune to the effects of predation.

• Schaefer, H. Martin and Graeme D. Ruxton. 2009a. Deception in plants: mimicry or perceptual exploitation? Trends in Ecology and Evolution. 24:676-685.

  This article looks at mimicry and perceptual exploitation done by plants to animals. The suggestion is that perceptual exploitation is a potential lead in to the evolution of mimicry. Plants would want to manipulate animals in certain ways in order to be pollinated.

• Stevens, Martin and Isabel S. Winney, Abi Cantor and Julia Graham. 2009a. Outline and surface disruption in animal camouflage. Proceedings of the Royal Society of Biological Sciences. 276:781-786.

  This study looks at disruptive coloration of prey as viewed by avian predators. The findings show that disruptive coloration is a helpful prey concealment tactic, provided that the disruption is not along the outline of the body, thus creating a surface disruption. Object detection is more difficult if the true-body outline is hard to distinguish.

• Stevens, Martin, Innes C Cuthill, Amy M.M Windsor and Hannah J Walker. 2006a. Disruptive contrast in animal camouflage. Proceedings of the Royal Society of Biological Sciences. 273:2433-2438.

  This study looked at various types of disruptive coloration, including the counter-intuitive idea that conspicuous patterns might aid concealment. The findings showed that any disruptive contrast, including incomplete patterns, were of help to animals to avoid predation.

• Théry, Marc. 2007a. Colours of background reflected light and of the prey’s eye affect adaptive coloration in female crab spiders. Animal Behavior. 73:797-804.

  This article looks at how crab spiders are able to change colors, including through the ingestion of certain prey. The suggestion that pigment ingestion is not just used to change color, but to signal to females the hunting abilities of potential mates, was also made.

• Théry, Marc and Jéröme Casas. 2009a. The multiple disguises of spiders: web colour and decorations, body colour and movement. Philosophical Transactions of the Royal Society of Biological Sciences. 364:471-480.

  This article discusses the potential camouflage and mimicry done by spiders for prey attraction and predator deterrence.

• Théry, Marc, Martine Debut, Doris Gomez and Jéröme Casas. 2004a. Specific color sensitivities of prey and predator explain camouflage in different visual systems. Behavioral Ecology. 25-29.

  This study looked at the chromatic contrast (viewing from close range) and achromatic contrast (viewing from long-range) of female crab spiders on daisies. From this study, more questions about bird predators’ ability to constrain spider crypsis arise.

• Wignall, Anne E., Astrid M. Heiling, Ken Cheng and Marie E. Herberstein. 2005a. Symmetry Preferences in Honeybees and their Crab Spider Predators. Ethology. 112:510-518.

  This article looks at honeybee and spider symmetry preferences when choosing where to pollinate. The study removed olfactory clues, which is likely to be used in foraging decisions.

• "White Crab Spider (Thomisus Spectabilis)." OzAnimals - Australian Wildlife . Web. 20 Apr. 2010. (External Link) .