Feeding and Development of the Glassy-Winged Sharpshooter, Homalodisca vitripennis, on Australian Native Plant Species and Implications for Australian Biosecurity

Geoff M. Gurr,Lorraine J. Spohr,Matthew P. Daugherty,Mark S. Hoddle,Anna A. Rathé,Immo A. Hansen,Leigh J. Pilkington

doi:10.1371/journal.pone.0090410

Abstract

In any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. The glassy-winged sharpshooter, Homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, Xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas and are considered to be highly invasive. Neither has been detected in Australia. Twelve Australian native plant species present in the USA were observed over two years for suitability as H. vitripennis feeding, oviposition and nymph development hosts. Hosts providing evidence of adult or nymph presence were Leptospermum laevigatum, Acacia cowleana, Eremophila divaricata, Eucalyptus wandoo, Hakea laurina, Melaleuca laterita and Swainsona galegifolia. An oviposition-suitability field study was conducted with citrus, a favoured oviposition host, as a positive control. Citrus and L. laevigatum, A. cowleana, B. ericifolia×B. spinulosa, C. pulchella, E. divaricata, E. wandoo, H. laurina, and S. galegifolia were found to be oviposition hosts. Egg parasitism by the mymarid parasitoid Gonatocerus ashmeadi was observed on all Australian plants. A number of Australian plants that may facilitate H. vitripennis invasion have been identified and categorised as ‘high risk’ due to their ability to support all three life stages (egg, nymph and adult) of the insect in the field (L. laevigatum, A. cowleana, E. divaricata, H. laurina, and S. galegifolia). The implications of these host status and natural enemy research findings are discussed and placed in an Australian invasion context.

Highlights

Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is an invasive pest that has expanded its geographical range significantly, in part due to having a polyphagous feeding habit
It has been shown that, possible [15], H. vitripennis rarely persists on just one host plant species, and that mortality occurs if caged on a sub-optimal host [14]
Twelve Australian native plant species were sourced from a commercial nursery in California and were between 0.2 and 0.8 m tall, each in a standard 3.7 L plant pot with medium containing pumice for drainage

Summary

Introduction

Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) is an invasive pest that has expanded its geographical range significantly, in part due to having a polyphagous feeding habit. Homalodisca vitripennis feeds on over 100 plant species from 31 families including exotic crop, ornamental, and native American species [1,2,3,4]. The ability of H. vitripennis to use many plant species as hosts for reproduction, development, and feeding allows the insect to cope with diurnal and seasonal changes in xylem fluid [14]. The insect may feed on a single sub-optimal species for short periods of time if the energy expended in taking up and metabolising food is not exceeded by the energy in the xylem fluid [13,14,16]

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Conclusion