title: Geographic distribution and relative abundance of the invasive glassy-winged sharpshooter: effects of temperature and egg parasitoids.
abstract: The capacity to predict the geographic distribution and relative abundance of invasive species is pivotal to developing policy for eradication or control and management. Commonly used methods fall under the ambit of ecological niche models (ENMs). These methods were reviewed and shortcomings  identified. Weather-driven physiologically based demographic models (PBDMs) are proposed that resolve many of the deficiencies of ENMs. The PBDM approach is used to analyze the invasiveness of the polyphagous glassy-winged sharpshooter (Homalodisca vitripennis [Germar]), a pest native to the  southeastern United States and northeastern Mexico that extended its range into California in 1989. Glassy-winged sharpshooter vectors the pathogenic bacterium, Xylella fastidiosa (Wells) that causes Pierce's disease in grape and scorch-like diseases in other plants. PBDMs for glassy-winged  sharpshooter and its egg parasitoids (Gonatocerus ashmeadi Girault and G. triguttatus Girault) were developed and linked to a PBDM for grape published by Wermelinger et al. (1991). Daily weather data from 108 locations across California for the period 1995-2006 were used to drive the  PBDM system, and GRASS GIS was used to map the simulation results. The geographic distribution of glassy-winged sharpshooter, as observed, is predicted to be largely restricted to the warm areas of southern California, with the action of the two egg parasitoids reducing its abundance >90%.  The average indispensable mortality contributed by G. triguttatus is <1%. A temperature-dependent developmental rate model for X. fastidiosa was developed that suggests its geographic range is also limited to the warm inland areas of southern California. Biological control of glassy-winged  sharpshooter further decreases the pathogen's relative range. Climate warming scenarios of +2°C and +3°C suggest that the distribution and severity of glassy-winged sharpshooter and X. fastidiosa will increase in the agriculturally rich central valley of California. The utility of  holistic analyses for formulating control policy and tactics for invasive species is discussed.
authors.affiliation: Center for the Analysis of Sustainable Agricultural Systems (CASAS Global), Kensington, CA 94707, USA. CASAS.Global@berkeley.edu
authors.forename: Andrew Paul
authors.initials: AP
authors.lastname: Gutierrez
authors.forename: Luigi
authors.initials: L
authors.lastname: Ponti
authors.forename: Mark
authors.initials: M
authors.lastname: Hoddle
authors.forename: Rodrigo P P
authors.initials: RP
authors.lastname: Almeida
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Irvin
mesh_terms: D000818:Animals; D002140:California; D004463:Ecology / Q000379:methods*; D005843:Geography; D006430:Hemiptera / Q000469:parasitology / Q000502:physiology*; D007303:Insect Vectors; D058865:Introduced Species; D008954:Models, Biological; D010063:Ovum / Q000469:parasitology; D010572:Pest Control, Biological; D010935:Plant Diseases; D011156:Population Density; D012044:Regression Analysis; D013696:Temperature