Passiflora maliformis is an introduced plant in Australia but its flowers are known to attract the native Jarvis’s fruit fly, Bactrocera jarvisi (Tryon). The present study identifies and quantifies likely attractant(s) of male B. jarvisi in P. maliformis flowers. The chemical compositions of the inner and outer coronal filaments, anther, stigma, ovary, sepal, and petal of P. maliformis were separately extracted with ethanol and analyzed using gas chromatography-mass spectrometry (GC-MS). Polyisoprenoid lipid precursors, fatty acids and their derivatives, and phenylpropanoids were detected in P. maliformis flowers. Phenylpropanoids included raspberry ketone, cuelure, zingerone, and zingerol, although compositions varied markedly amongst the flower parts. P. maliformis flowers were open for less than one day, and the amounts of some of the compounds decreased throughout the day. The attraction of male B. jarvisi to P. maliformis flowers is most readily explained by the presence of zingerone in these flowers.

Australia and Southeast Asia are hotspots of global diversity in the fruit-fly genus Bactrocera. Although a great diversity of species has been long recognised, evolutionary relationships are poorly understood, largely because previous sequencing techniques have provided insufficient historical signal for phylogenetic reconstruction. Poorly understood biogeographic history in Bactrocera has prevented a deeper understanding of migratory patterns in this economically important pest group. Using representatives from Australia and Malaysia, we tested the utility of a genome-reduction approach that generates thousands of single-nucleotide polymorphisms for phylogenetic reconstructions. This approach has high utility for species identification because of the ease of sample addition over time, and the species-level specificity able to be achieved with the markers. These data have provided a strongly supported phylogenetic tree congruent with topologies generated using more intensive sequencing approaches. In addition, our results do not support taxonomic assignments to species complex for a number of species, such as B. endiandrae in the dorsalis complex, yet find a close relationship between B. pallida and the dorsalis species. Our data have further validated non-monophyletic evolution of male response to primary attractants. We also showed at least two diversification events between Australia and Southeast Asia, indicating trans-regional dispersal in important pest species.

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Floral constituents of the Australian tar tree, Semecarpus australiensis, distributed in Melanesia and Northern Australia, were extracted with solvent, and analyzed by gas chromatography-mass spectrometry. The main constituents were 16-and 18-carbon fatty acids and their ethyl esters. Amongst the 67 identified compounds, zingerone was detected in minute quantity, providing the chemical basis for previous observations of fruit fly attraction to the flowers. The present study is the first to report the chemical profile of tar tree flowers.