title: Feeding Experience Affects the Behavioral Response of Polyphagous Gypsy Moth Caterpillars to Herbivore-induced Poplar Volatiles.
abstract: Plant volatiles influence host selection of herbivorous insects. Since volatiles often vary in space and time, herbivores (especially polyphagous ones) may be able to use these compounds as cues to track variation in host plant quality based on their innate abilities and previous experience. We investigated the behavioral response of naïve (fed on artificial diet) and experienced (fed on poplar) gypsy moth (Lymantria dispar) caterpillars, a polyphagous species, towards constitutive and herbivore-induced black poplar (Populus nigra) volatiles at different stages of herbivore attack. In Y-tube olfactometer assays, both naïve and experienced caterpillars were attracted to constitutive volatiles and volatiles released after short-term herbivory (up to 6 hr). Naïve caterpillars also were attracted to volatiles released after longer-term herbivory (24-30 hr), but experienced caterpillars preferred the odor of undamaged foliage. A multivariate statistical analysis comparing the volatile emission of undamaged plants vs. plants after short and longer-term herbivory, suggested various compounds as being responsible for distinguishing between the odors of these plants. Ten compounds were selected for individual testing of caterpillar behavioral responses in a four-arm olfactometer. Naïve caterpillars spent more time in arms containing (Z)-3-hexenol and (Z)-3-hexenyl acetate than in solvent permeated arms, while avoiding benzyl cyanide and salicyl aldehyde. Experienced caterpillars avoided benzyl cyanide and preferred (Z)-3-hexenyl acetate and the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) over solvent. Only responses to DMNT were significantly different when comparing experienced and naïve caterpillars. The results show that gypsy moth caterpillars display an innate behavioral response towards constitutive and herbivore-induced plant volatiles, but also that larval behavior is plastic and can be modulated by previous feeding experience.
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany. A.C.McCormick@Massey.ac.nz.|Institute of Agriculture and Environment, Massey University, Private Bag 11222, 4442, Palmerston North, New Zealand. A.C.McCormick@Massey.ac.nz.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: McCormick
authors.affiliation: Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.|Department of Behavioral Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 7, 82319, Seewiesen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Reinecke
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.affiliation: Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
authors.forename: Sybille B
authors.initials: SB
authors.lastname: Unsicker
mesh_terms: D000818:Animals; D003463:Cues; D005247:Feeding Behavior / Q000187:drug effects*; D060434:Herbivory / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects*; D009812:Odorants / Q000032:analysis; D032107:Populus / Q000378:metabolism*; D011235:Predatory Behavior / Q000187:drug effects; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D055549:Volatile Organic Compounds
keywords: Behavioral plasticity; Herbivore-induced plant volatiles (HIPV); Host-plant selection; Lepidoptera; Polyphagous insects; Salicaceae