title: Non-target effects of transgenic blight-resistant American chestnut (Fagales: Fagaceae) on insect herbivores.
abstract: American chestnut [Castanea dentata (Marshall) Borkhausen], a canopy dominant species across wide swaths of eastern North America, was reduced to an understory shrub after introduction of the blight fungus [Cryphonectria parasitica (Murrill) Barr] in the early 1900s. Restoration of  American chestnut by using biotechnology is promising, but the imprecise nature of transgenesis may inadvertently alter tree phenotype, thus potentially impacting ecologically dependent organisms. We quantified effects of genetic engineering and fungal inoculation of trees on insect herbivores  by using transgenic American chestnuts expressing an oxalate oxidase gene and wild-type American and Chinese (C. mollissima Blume) chestnuts. Of three generalist folivores bioassayed, only gypsy moth [Lymantria dispar (L.)] was affected by genetic modification, exhibiting faster growth on  transgenic than on wild-type chestnuts, whereas growth of polyphemus moth [Antheraea polyphemus (Cramer)] differed between wild-type species, and fall webworm [Hyphantria cunea (Drury)] performed equally on all trees. Inoculation of chestnuts with blight fungus had no effect on the growth  of two herbivores assayed (polyphemus moth and fall webworm). Enhanced fitness of gypsy moth on genetically modified trees may hinder restoration efforts if this invasive herbivore's growth is improved because of transgene expression.
authors.affiliation: Department of Environmental and Forest Biology, SUNY-College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Post
authors.forename: D
authors.initials: D
authors.lastname: Parry
mesh_terms: D000818:Animals; D029962:Fagaceae / Q000235:genetics* / Q000382:microbiology / Q000469:parasitology; D005260:Female; D060434:Herbivory; D006790:Host-Parasite Interactions; D007814:Larva / Q000254:growth & development; D008297:Male; D009036:Moths / Q000502:physiology*; D010935:Plant Diseases; D030821:Plants, Genetically Modified / Q000469:parasitology*