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Abstract

The preference of two allopatric populations of Culex annulirostris mosquitoes in South Australia (SA) for guinea pigs and chickens was investigated using host-baited traps in the field and in a flight tunnel for laboratory assays. Mosquitoes from the Riverland of SA preferred guinea pigs, those from northeast SA preferred chickens. In the field, 2184 Cx. annulirostris were captured during four experiments in each region. The proportion choosing chicken was 0.5393 in northeast SA and 0.4348 in the Riverland. In the laboratory, replicate trials utilizing 15 mosquitoes at a time yielded results concordant with field assays. This study demonstrates variation in Cx. annulirostris host preference throughout this species geographic range. Semiochemical analysis of the two host species was performed on solvent extractions and volatile trapping samples from fur and feathers, respectively. This revealed differences that are likely to be the basis for host discrimination by Cx. annulirostris.

Volatile compounds from the integument of White Leghorn Chickens (Gallus gallus domesticus L.): Candidate attractants of ornithophilic mosquito species*

“…Hexanal, benzaldehyde, and nonanal have been reported previously from both chicken feathers and guinea pig hair [20]. In addition to hexanal, we detected other aldehydes including heptanal, octanal, decanal, and benzaldehyde.…”

“…Two diones, 2,4-hexanedione (enol) and 2,5-hexanedione were also identified. was reported by Williams et al [20] as a volatile produced from guinea pigs but was not detected in their collections from chicken feathers. The presence of 2,5-hexanedione, a metabolite found in human urine that arises from exposure to hexane, is of concern because of its association with polyneuropathy [27].…”

“…when added to a trap, provided that trap placement is at the proper height [19]. The work of Williams et al [20] combined chemical analysis and bioassays to identify compounds that mediate host-seeking behavior of Culex annulirostris Skuse, a mosquito found in Australia and nearby regions surrounding the Australian continent. They employed solid phase microextraction (SPME) fibers to concentrate emana-tions for subsequent GC/MS identification both from solvent extraction of the fur or feathers and from concentration of volatiles in the headspace.…”

Sheep Skin Odor Improves Trap Captures of Mosquito Vectors of Rift Valley Fever

“…Among the species complexes captured, there are known marked differences in olfactory responses between members of the complexes [39], [40]. Culex pipiens preferentially feed on birds [41] although they can adapt and readily feed on mammals in proportions possibly based on host abundance [42]. The observed differences in trap responses in the highest trap treatments (i.e., LC and LCF) at both districts may indicate different spatial feeding preferences in geographically separate populations.…”

Headspace solid phase microextraction/gas chromatography–mass spectrometry combined to chemometric analysis for volatile organic compounds determination in canine hair: A new tool to detect dog contamination by visceral leishmaniasis

“…Some of the compounds identified in the present study were already recognized as attractive to hematophagous mosquitoes. Tetradecane is one of the main exhaled compounds from chicken and it is a potential attractive to Culex annulirostris, a vector of diseases such as Ross River fever, Barman forest virus, Kunjin virus and Murray Valley encephalitis [37]. Nonanal elucidated the electrophysiologic and behavior responses of Culex quinquefasciatus, human philariosys vector [38], while 2-hexanone, benzaldehyde and hexanal were reported as important compounds in L. longipalpis orientation [39] and tridecane to present repellent proprieties to Anoplolepis longipalpis, Sitotroga cerealella and C. quinquefasciatus [40].…”