Open AccessSpecies limits, quarantine risk and the intrigue of a polyphagous invasive pest with highly restricted host relationships in its area of invasion
Author(s) -
Rafter Michelle A.,
Hereward James P.,
Walter Gimme H.
Publication year - 2013
Publication title -
evolutionary applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.776
H-Index - 68
ISSN - 1752-4571
DOI - 10.1111/eva.12096
Subject(s) - biology , thrips , quarantine , clade , pest analysis , host (biology) , range (aeronautics) , ecology , gene flow , generalist and specialist species , invasive species , phylogenetic tree , zoology , botany , genetic variation , habitat , genetics , gene , materials science , composite material
Abstract Scirtothrips aurantii is a generalist horticultural pest in its native African range and recently established quite widely in Australia on the invasive succulent weed B ryophyllum delagoense . Paradoxically, this thrips is not polyphagous in its incursive range. The issue is principally one of quarantine. Will the thrips in Australia shift, perhaps adaptively, to citrus, and should the primary focus be on containment around A ustralian citrus, or does the real quarantine risk exist offshore with thrips present on citrus in A frica? We examined the phylogenetic relationships between B ryophyllum ‐associated thrips populations in Australia and populations sampled from various host plant species in S outh A frica (including B ryophyllum ) using both CO 1 and 28s markers. Eight variable microsatellite markers were developed to assess the extent of gene flow between the thrips on different hosts in S outh A frica. The COI phylogeny resolved S. aurantii into three distinct clades with samples collected from B. delagoense in South Africa and Australia representing a single clade, a second clade associated with Gloriosa lilies and the third with horticultural hosts. The microsatellite analysis confirmed that the populations associated with citrus and Bryophyllum do not hybridize with one another in sympatry. We conclude that the citrus‐damaging thrips are not currently present in A ustralia and remain a serious quarantine concern in relation to A ustralian horticulture.