title: Do Fruit Ripening Volatiles Enable Resource Specialism in Polyphagous Fruit Flies?
abstract: Frugivorous tephritid fruit flies have lineages with high levels of host generalism. These insects use olfaction to locate fruits, but how they are able to recognize the odors of so many different host species is poorly understood. We used a series of behavioral experiments to investigate the role of fruit ripening volatiles as host cues in the Queensland fruit fly, Bactrocera tryoni (Froggatt), a polyphagous pest in Australia. Odors of mature guava (Psidium guajava) attracted female and male flies more strongly than three other ripening stages and guava pulp. We analyzed volatiles from guava odor and selected eleven compounds, all of which elicited an electrophysiological response in the antenna of female flies. Three of these, ethyl acetate, ethyl butyrate, and ethyl propionate, were released at the highest rates from the most attractive ripening stage. In behavioral trials, these three esters were not attractive individually, whereas a combination was necessary and sufficient in attracting female flies. The three-component blend was as attractive as the entire 11-component blend, which without these key volatiles was not attractive. Moreover, injecting low ranking hosts (squash and cucumber) with the three volatiles increased attraction in ovipositing female flies. These fruit flies are classed as generalists, but like many polyphagous insects they could be regarded as resource specialists, preferring specific plant reproductive stages with predictable odor cues. Exploring olfaction from this perspective could improve our understanding of host choice in polyphagous insects, and the selection of volatiles to be used as attractants in insect pest management.
authors: Department of Economic Development, Jobs, Transport & Resources, Biosciences Research, AgriBio Centre, 5 Ring Road, Bundoora, VIC, 3083, Australia. paul.cunningham@ecodev.vic.gov.au.|Queensland University of Technology, Gardens Point, Brisbane, QLD, 4001, Australia. paul.cunningham@ecodev.vic.gov.au.
authors: John Paul
authors: JP
authors: Cunningham
authors: Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden.
authors: Mikael A
authors: MA
authors: Carlsson
authors: Queensland University of Technology, Gardens Point, Brisbane, QLD, 4001, Australia.
authors: Tommaso F
authors: TF
authors: Villa
authors: Department of Plant Protection Biology, Swedish University of Agricultural Science, Alnarp, Sweden.
authors: Teun
authors: T
authors: Dekker
authors: Queensland University of Technology, Gardens Point, Brisbane, QLD, 4001, Australia.|Cooperative Research Centre for Plant Biosecurity, ACT, Bruce, Australia.
authors: Anthony R
authors: AR
authors: Clarke
mesh_terms: D000818:Animals; D005260:Female; D005638:Fruit / Q000737:chemistry / Q000469:parasitology / Q000502:physiology; D007300:Insect Control / Q000379:methods; D008297:Male; D009812:Odorants / Q000032:analysis*; D010058:Oviposition; D031647:Psidium / Q000737:chemistry* / Q000469:parasitology / Q000502:physiology; D012903:Smell; D033621:Tephritidae / Q000033:anatomy & histology / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000378:metabolism
chemical_list: D055549:Volatile Organic Compounds
keywords: Bactrocera tryoni; Host plant; Olfaction; Pest management; Polyphagous