Titel: Acoustic alarm signalling facilitates predator
protection of treehoppers by mutualist
ant bodyguards
Auteur(s): Manuel A. Morales, Jennifer L. Barone and Charles S. Henry
Gepubliceerd in: Proceedings B
Jaar van publicatie: 2008
Abstract: Mutualism is a net positive interaction that includes varying degrees of both costs and benefits. Because
tension between the costs and benefits of mutualism can lead to evolutionary instability, identifying
mechanisms that regulate investment between partners is critical to understanding the evolution and
maintenance of mutualism. Recently, studies have highlighted the importance of interspecific signalling as
one mechanism for regulating investment between mutualist partners. Here, we provide evidence for
interspecific alarm signalling in an insect protection mutualism and we demonstrate a functional link
between this acoustic signalling and efficacy of protection. The treehopper Publilia concava Say
(Hemiptera: Membracidae) is an insect that provides ants with a carbohydrate-rich excretion called
honeydew in return for protection from predators. Adults of this species produce distinct vibrational
signals in the context of predator encounters. In laboratory trials, putative alarm signal production
significantly increased following initial contact with ladybeetle predators (primarily Harmonia axyridis
Pallas, Coleoptera: Coccinellidae), but not following initial contact with ants. In field trials, playback of a
recorded treehopper alarmsignal resulted in a significant increase in both ant activity and the probability of
ladybeetle discovery by ants relative to both silence and treehopper courtship signal controls. Our results
show that P. concava treehoppers produce alarm signals in response to predator threat and that this
signalling can increase effectiveness of predator protection by ants.
Webadres:
http://www.publishing.royalsociety.org/ ... 080410.pdf
protection of treehoppers by mutualist
ant bodyguards
Auteur(s): Manuel A. Morales, Jennifer L. Barone and Charles S. Henry
Gepubliceerd in: Proceedings B
Jaar van publicatie: 2008
Abstract: Mutualism is a net positive interaction that includes varying degrees of both costs and benefits. Because
tension between the costs and benefits of mutualism can lead to evolutionary instability, identifying
mechanisms that regulate investment between partners is critical to understanding the evolution and
maintenance of mutualism. Recently, studies have highlighted the importance of interspecific signalling as
one mechanism for regulating investment between mutualist partners. Here, we provide evidence for
interspecific alarm signalling in an insect protection mutualism and we demonstrate a functional link
between this acoustic signalling and efficacy of protection. The treehopper Publilia concava Say
(Hemiptera: Membracidae) is an insect that provides ants with a carbohydrate-rich excretion called
honeydew in return for protection from predators. Adults of this species produce distinct vibrational
signals in the context of predator encounters. In laboratory trials, putative alarm signal production
significantly increased following initial contact with ladybeetle predators (primarily Harmonia axyridis
Pallas, Coleoptera: Coccinellidae), but not following initial contact with ants. In field trials, playback of a
recorded treehopper alarmsignal resulted in a significant increase in both ant activity and the probability of
ladybeetle discovery by ants relative to both silence and treehopper courtship signal controls. Our results
show that P. concava treehoppers produce alarm signals in response to predator threat and that this
signalling can increase effectiveness of predator protection by ants.
Webadres:
http://www.publishing.royalsociety.org/ ... 080410.pdf