title: Effect of feeding by the western conifer seed bug, Leptoglossus occidentalis, on the major storage reserves of developing seeds and on seedling vigor of Douglas-fir.
abstract: The impact of feeding by the western conifer seed bug (Leptoglossus occidentalis Heidemann) on storage reserves of developing seeds of Douglas-fir (Pseudostuga menziesii (Mirb.) Franco) was studied by caging nymphal and adult seed bugs on cones during late-season development, and nymphs on cones during early, mid- and late-season development. Analysis of the major storage reserves of partially damaged seeds revealed that late-season feeding by each life stage and feeding by nymphs at all three stages of cone development significantly reduced the amounts of lipid and buffer-insoluble (crystalloid) protein in seeds at harvest by up to 78 and 97%, respectively. Seeds showing light to moderate damage on radiographs did not exhibit a reduction in the amount of buffer-soluble (matrix) protein. Seeds damaged by feeding during early development compensated in part by continuing to synthesize lipid and crystalloid protein. Light or moderate damage to mature Douglas-fir seeds exposed to L. occidentalis in the laboratory reduced seedling emergence by > 80%, but the seedlings that emerged successfully appeared to suffer no adverse effects when grown under standard nursery conditions.
authors.affiliation: Centre for Environmental Biology, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: S L
authors.initials: SL
authors.lastname: Bates
authors.forename: C G
authors.initials: CG
authors.lastname: Lait
authors.forename: J H
authors.initials: JH
authors.lastname: Borden
authors.forename: A R
authors.initials: AR
authors.lastname: Kermode
mesh_terms: D000818:Animals; D006430:Hemiptera; D008055:Lipids / Q000502:physiology; D010940:Plant Proteins / Q000502:physiology; D028224:Pseudotsuga / Q000254:growth & development / Q000469:parasitology / Q000502:physiology*; D012639:Seeds / Q000254:growth & development / Q000502:physiology*; D014197:Trees / Q000254:growth & development / Q000502:physiology*
chemical_list: D008055:Lipids; D010940:Plant Proteins