title: Dynamics of short- and long-term association between a bacterial plant pathogen and its arthropod vector.
abstract: The dynamics of association between pathogens and vectors can strongly influence epidemiology. It has been proposed that wilt disease epidemics in cucurbit populations are sustained by persistent colonization of beetle vectors (Acalymma vittatum) by the bacterial phytopathogen Erwinia tracheiphila. We developed a qPCR method to quantify E. tracheiphila in whole beetles and frass and used it to assess pathogen acquisition and retention following variable exposure to infected plants. We found that (i) E. tracheiphila is present in frass in as little as three hours after feeding on infected plants and can be transmitted with no incubation period by vectors given brief exposure to infected plants, but also by persistently colonized vectors several weeks following exposure; (ii) duration of exposure influences rates of long-term colonization; (iii) frass infectivity (assessed via inoculation experiments) reflects bacterial levels in frass samples across time; and (iv) vectors rarely clear E. tracheiphila infections, but suffer no apparent loss of fitness. These results describe a pattern conducive to the effective maintenance of E. tracheiphila within cucurbit populations.
authors.affiliation: 1] Department of Entomology, The Pennsylvania State University, University Park, PA 16802 [2] Department of Organismic and Evolutionary Biology, Harvard University, 02138.
authors.forename: L R
authors.initials: LR
authors.lastname: Shapiro
authors.affiliation: Department of Entomology, The Pennsylvania State University, University Park, PA 16802.
authors.forename: I
authors.initials: I
authors.lastname: Seidl-Adams
authors.affiliation: 1] Department of Entomology, The Pennsylvania State University, University Park, PA 16802 [2] Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.
authors.forename: C M
authors.initials: CM
authors.lastname: De Moraes
authors.affiliation: Department of Biology, The Pennsylvania State University, University Park, PA 16802.
authors.forename: A G
authors.initials: AG
authors.lastname: Stephenson
authors.affiliation: 1] Department of Entomology, The Pennsylvania State University, University Park, PA 16802 [2] Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.
authors.forename: M C
authors.initials: MC
authors.lastname: Mescher
mesh_terms: D000818:Animals; D001179:Arthropod Vectors / Q000382:microbiology*; D001517:Coleoptera / Q000382:microbiology*; D028464:Cucurbita / Q000382:microbiology / Q000469:parasitology; D004885:Erwinia / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology / Q000469:parasitology; D012337:RNA, Ribosomal, 18S / Q000378:metabolism
chemical_list: D012337:RNA, Ribosomal, 18S