title: Can insect egg deposition 'warn' a plant of future feeding damage by herbivorous larvae?
abstract: Plant anti-herbivore defence is inducible by both insect feeding and egg deposition. However, little is known about the ability of insect eggs to induce defences directed not against the eggs themselves, but against larvae that subsequently hatch from the eggs. We studied how oviposition (OP) by the sawfly Diprion pini on Pinus sylvestris foliage affects the plant's defensive potential against sawfly larvae. Larvae that initiated their development on P. sylvestris twigs on which they hatched from eggs gained less weight and suffered higher mortality than those fed on egg-free twigs. The poor performance of these larvae also affected the next herbivore generation since fecundity of resulting females was lower than that of females which spent their larval development on egg-free pine. Transcript levels of P. sylvestris sesquiterpene synthases (PsTPS1, PsTPS2) were increased by D. pini OP, reached their highest levels just before larval hatching, and decreased when larvae started to feed. However, concentrations of terpenoid and phenolic metabolites presumed to act as feeding deterrents or toxins for herbivores did not change significantly after OP and feeding. Nevertheless, our performance data suggest that insect egg deposition may act to 'warn' a plant of upcoming feeding damage by larvae.
authors.affiliation: Institute of Biology, Freie Universität Berlin, Haderslebener Strasse 9, 12163 Berlin, Germany.
authors.forename: Ivo
authors.initials: I
authors.lastname: Beyaert
authors.forename: Diana
authors.initials: D
authors.lastname: Köpke
authors.forename: Josefin
authors.initials: J
authors.lastname: Stiller
authors.forename: Almuth
authors.initials: A
authors.lastname: Hammerbacher
authors.forename: Kinuyo
authors.initials: K
authors.lastname: Yoneya
authors.forename: Axel
authors.initials: A
authors.lastname: Schmidt
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gershenzon
authors.forename: Monika
authors.initials: M
authors.lastname: Hilker
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D005260:Female; D020387:Food Chain; D008401:Gas Chromatography-Mass Spectrometry; D005786:Gene Expression Regulation; D005858:Germany; D060434:Herbivory; D006927:Hymenoptera / Q000254:growth & development / Q000502:physiology*; D007814:Larva / Q000235:genetics / Q000502:physiology; D010058:Oviposition; D028223:Pinus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry; D060888:Real-Time Polymerase Chain Reaction; D012717:Sesquiterpenes / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism
chemical_list: D012717:Sesquiterpenes; D013729:Terpenes; D019883:Alkyl and Aryl Transferases