title: Invasive mutualisms between a plant pathogen and insect vectors in the Middle East and Brazil.
abstract: Complex multi-trophic interactions in vectorborne diseases limit our understanding and ability to predict outbreaks. Arthropod-vectored pathogens are especially problematic, with the potential for novel interspecific interactions during invasions. Variations and novelties in plant-arthropod-pathogen triumvirates present significant threats to global food security. We examined aspects of a phytoplasma pathogen of citrus across two continents. 'CandidatusPhytoplasma aurantifolia' causes Witches' Broom Disease of Lime (WBDL) and has devastated citrus production in the Middle East. A variant of this phytoplasma currently displays asymptomatic or 'silent' infections in Brazil. We first studied vector capacity and fitness impacts of the pathogen on its vectors. The potential for co-occurring weed species to act as pathogen reservoirs was analysed and key transmission periods in the year were also studied. We demonstrate that two invasive hemipteran insects-Diaphorina citriandHishimonus phycitis-can vector the phytoplasma. Feeding on phytoplasma-infected hosts greatly increased reproduction of its invasive vectorD. citriboth in Oman and Brazil; suggesting that increased fitness of invasive insect vectors thereby further increases the pathogen's capacity to spread. Based on our findings, this is a robust system for studying the effects of invasions on vectorborne diseases and highlights concerns about its spread to warmer, drier regions of Brazil.
authors.affiliation: Department of Entomology , Universidade Federal de Viçosa , Viçosa, Minas Gerais, CEP 35.700-900 , Brazil.
authors.forename: Renan Batista
authors.initials: RB
authors.lastname: Queiroz
authors.affiliation: Department of Entomology , Universidade Federal de Viçosa , Viçosa, Minas Gerais, CEP 35.700-900 , Brazil.
authors.forename: Philip
authors.identifier: 0000-0001-6013-1043
authors.initials: P
authors.lastname: Donkersley
authors.affiliation: Department of Phytopathology , Universidade Federal de Viçosa , Viçosa, Minas Gerais, CEP 35.700-900 , Brazil.
authors.forename: Fábio Nascimento
authors.initials: FN
authors.lastname: Silva
authors.affiliation: Department of Crop Sciences, College of Agricultural and Marine Sciences , Sultan Qaboos University , PO Box 34, Al-Khod 123 , Oman.
authors.forename: Issa Hashil
authors.initials: IH
authors.lastname: Al-Mahmmoli
authors.affiliation: Department of Crop Sciences, College of Agricultural and Marine Sciences , Sultan Qaboos University , PO Box 34, Al-Khod 123 , Oman.
authors.forename: Abdullah Mohammed
authors.initials: AM
authors.lastname: Al-Sadi
authors.affiliation: Department of Phytopathology , Universidade Federal de Viçosa , Viçosa, Minas Gerais, CEP 35.700-900 , Brazil.
authors.forename: Claudine Márcia
authors.initials: CM
authors.lastname: Carvalho
authors.affiliation: Department of Entomology , Universidade Federal de Viçosa , Viçosa, Minas Gerais, CEP 35.700-900 , Brazil.
authors.forename: Simon L
authors.initials: SL
authors.lastname: Elliot
keywords: Citrus aurantifolia; Diaphorina citri; Hishimonus phycitis; acid lime; insect vectors; silent infection