« Previous AbstractFungal infection reduces herbivore-induced plant volatiles of maize but does not affect naive parasitoids    Next AbstractCopper and herbivory lead to priming and synergism in phytohormones and plant volatiles in the absence of salicylate-jasmonate antagonism »

J Chem Ecol

Title:		Caterpillar footprints as host location kairomones for Cotesia marginiventris: persistence and chemical nature
Author(s):		Rostas M; Wolfling M;
Address:		"Department of Botany II, University of Wurzburg, Germany. michael.rostas@botanik.uni-wuerzburg.de"
Journal Title:		J Chem Ecol
Year:		2009
Volume:		20090120
Issue:		1
Page Number:		20 - 27
DOI:		10.1007/s10886-009-9590-z
ISSN/ISBN:		1573-1561 (Electronic) 0098-0331 (Linking)
Abstract:		"Herbivores walking over the epicuticular wax layer of a plant may leave tracks that disclose their presence to hunting predators or parasitoids. The braconid wasp Cotesia marginiventris is a solitary parasitoid of young noctuid caterpillars. It can locate potential hosts from a distance by orienting toward the scent of herbivore-damaged plants. Upon landing on the caterpillars' food plant, the female parasitoid searches for further cues (kairomones) that confirm the presence of a suitable host. In a previous study, we showed that C. marginiventris recognizes the chemical footprints of absent Spodoptera frugiperda caterpillars on a leaf. Here, we report on the persistence and chemical nature of this host location kairomone. In a series of behavioral assays, we confirmed that caterpillars of S. frugiperda leave chemical tracks that elicit characteristic antennation behavior in C. marginiventris for up to 2 days. Both hexane extracts of caterpillar footprints and of the larvae's ventral cuticle induced antennation and contained almost identical long-chain hydrocarbons, thus suggesting the prolegs and claspers as the kairomones' main source. A series of linear C(21) to C(32) alkanes accounted for ca 90% of all identified compounds. Female wasps showed significant antennation responses on leaves treated with a reconstructed blend of these n-alkanes. However, wasp responses were relatively weak. Therefore, we presume that minor compounds, such as monomethyl-branched alkanes, which were also found, may contribute additionally to host recognition"
Keywords:		Alkenes/chemistry/metabolism Animals Feeding Behavior Female Host-Parasite Interactions Pheromones/*chemistry/*metabolism Plant Leaves/parasitology Spodoptera/chemistry/*parasitology Time Factors Wasps/*physiology;
Notes:		"MedlineRostas, Michael Wolfling, Mirko eng Research Support, Non-U.S. Gov't 2009/01/21 J Chem Ecol. 2009 Jan; 35(1):20-7. doi: 10.1007/s10886-009-9590-z. Epub 2009 Jan 20"