title: Water-seeking behavior in worm-infected crickets and reversibility of parasitic manipulation.
abstract: One of the most fascinating examples of parasite-induced host manipulation is that of hairworms, first, because they induce a spectacular "suicide" water-seeking behavior in their terrestrial insect hosts and, second, because the emergence of the parasite is not lethal per se for the host that can live several months following parasite release. The mechanisms hairworms use to increase the encounter rate between their host and water remain, however, poorly understood. Considering the selective landscape in which nematomorph manipulation has evolved as well as previously obtained proteomics data, we predicted that crickets harboring mature hairworms would display a modified behavioral response to light. Since following parasite emergence in water, the cricket host and parasitic worm do not interact physiologically anymore, we also predicted that the host would recover from the modified behaviors. We examined the effect of hairworm infection on different behavioral responses of the host when stimulated by light to record responses from uninfected, infected, and ex-infected crickets. We showed that hairworm infection fundamentally modifies cricket behavior by inducing directed responses to light, a condition from which they mostly recover once the parasite is released. This study supports the idea that host manipulation by parasites is subtle, complex, and multidimensional.
authors.affiliation: GEMI/UMR CNRS-IRD 2724, Equipe: "Evolution des Systèmes Symbiotiques", IRD, 911 Avenue Agropolis, B.P. 5045, 34032 Montpellier Cedex 1, France.
authors.forename: Fleur
authors.initials: F
authors.lastname: Ponton
authors.forename: Fernando
authors.initials: F
authors.lastname: Otálora-Luna
authors.forename: Thierry
authors.initials: T
authors.lastname: Lefèvre
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Guerin
authors.forename: Camille
authors.initials: C
authors.lastname: Lebarbenchon
authors.forename: David
authors.initials: D
authors.lastname: Duneau
authors.forename: David G
authors.initials: DG
authors.lastname: Biron
authors.forename: Frédéric
authors.initials: F
authors.lastname: Thomas