title: Non-glandular trichomes ofSolanum carolinensedeter feeding byManduca sextacaterpillars and cause damage to the gut peritrophic matrix.
abstract: Plant trichomes constitute a first line of defence against insect herbivores. The pre- and post-ingestive defensive functions of glandular trichomes are well documented and include direct toxicity, adhesion, antinutrition and defence gene induction. By contrast, the defensive functions of non-glandular trichomes are less well characterized, although these structures are thought to serve as physical barriers that impede herbivore feeding and movement. We experimentally varied the density of stellate non-glandular trichomes in several ways to explore their pre- and post-ingestive effects on herbivores. Larvae ofManduca sexta(Sphingidae) initiated feeding faster and gained more weight onSolanum carolinense(Solanaceae) leaves having lower trichome densities (or experimentally removed trichomes) than on leaves having higher trichome densities. Adding trichomes to artificial diet also deterred feeding and adversely affected caterpillar growth relative to controls. Scanning electron and light microscopy revealed that the ingestion of stellate trichomes byM. sextacaterpillars caused extensive damage to the peritrophic membrane, a gut lining that is essential to digestion and pathogen isolation. These findings suggest that, in addition to acting as a physical barrier to deter feeding, trichomes can inhibit caterpillar growth and development via post-ingestive effects.
authors.affiliation: Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland.
authors.forename: Rupesh R
authors.initials: RR
authors.lastname: Kariyat
authors.affiliation: Department of Biology, Dickinson College, Carlisle, PA 17013, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Smith
authors.affiliation: Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Stephenson
authors.affiliation: Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland.
authors.forename: Consuelo M
authors.identifier: 0000-0001-6737-9842
authors.initials: CM
authors.lastname: De Moraes
authors.affiliation: Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland mescher@usys.ethz.ch.
authors.forename: Mark C
authors.identifier: 0000-0002-7908-3309
authors.initials: MC
authors.lastname: Mescher
mesh_terms: D000818:Animals; D004064:Digestive System / Q000473:pathology; D060434:Herbivory; D018402:Manduca; D018515:Plant Leaves / Q000033:anatomy & histology*; D032322:Solanum; D064201:Trichomes / Q000033:anatomy & histology*
keywords: Manduca sexta; Solanum carolinense; herbivory; peritrophic matrix; plant defence; trichomes