title: Plant inbreeding and prior herbivory influence the attraction of caterpillars (Manduca sexta) to odors of the host plant Solanum carolinense (Solanaceae).
abstract: The mediation of plant-insect interactions by plant odors has been studied extensively, but most previous work has focused on documenting the role of constitutive and herbivore- or pathogen-induced plant volatiles as foraging cues for insect herbivores and their natural enemies. Relatively little work has explored genotypic variation in plant-odor profiles within species, and few studies have addressed the perception and use of olfactory cues by lepidopteran larvae or other herbivores during feeding.
  
  
  METHODS
  We examined the effects of plant breeding (inbred vs. outbred individuals) and plant exposure to prior herbivory on the preferences of caterpillars (Manduca sexta) for odors of Solanum carolinense in leaf-disc and whole-plant choice assays.
  
  
  RESULTS
  Second- and third-instar larvae of M. sexta clearly and consistently preferred undamaged over herbivore-damaged plants of both breeding types and also consistently preferred inbred over outbred plants that had the same damage status. Similar preferences were observed even when plants were covered with bridal-veil cloth to mask visual cues, demonstrating that olfactory cues influence larval preferences.
  
  
  CONCLUSIONS
  The observed preferences are consistent with our previous findings regarding the constitutive and induced volatile profiles of inbred and outbred horsenettle plants and their effects on plant-herbivore interactions. They furthermore correspond to differences in host-plant quality predicted by previous work and, thus, suggest that naive larvae of M. sexta can accurately assess aspects of host-plant quality via olfactory cues perceived at a distance.
authors: Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, Pennsylvania 16802 USA.
authors: Rupesh R
authors: RR
authors: Kariyat
authors: Sarah R
authors: SR
authors: Scanlon
authors: Ryan P
authors: RP
authors: Moraski
authors: Andrew G
authors: AG
authors: Stephenson
authors: Mark C
authors: MC
authors: Mescher
authors: Consuelo M
authors: CM
authors: De Moraes
mesh_terms: D000818:Animals; D060434:Herbivory; D007178:Inbreeding; D007814:Larva; D018402:Manduca; D009812:Odorants; D010935:Plant Diseases; D018515:Plant Leaves; D032322:Solanum / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D055549:Volatile Organic Compounds
keywords: Manduca sexta; Solanum carolinense; herbivory; host location; inbreeding; induced defenses; resistance