Abstract

Background Mosquitoes use odours to find energy resources, blood hosts and oviposition sites. While these odour sources are normally spatio-temporally segregated in a mosquito's life history, here this study explored to what extent a combination of flower- and human-mimicking synthetic volatiles would attract the malaria vectorAnopheles gambiaesensu stricto (s.s.) Methods In the laboratory and in large (80 m(2)) outdoor cages in Tanzania, nulliparous and parousA. gambiae s.s.were offered choices between a blend of human skin volatiles (Skin Lure), a blend of floral volatiles (Vectrax), or a combination thereof. The blends consisted of odours that induce distinct, non-overlapping activation patterns in the olfactory circuitry, in sensory neurons expressing olfactory receptors (ORs) and ionotropic receptors (IRs), respectively. Catches were compared between treatments. Results In the laboratory nulliparous and parous mosquitoes preferred skin odours and combinations thereof over floral odours. However, in semi-field settings nulliparous were significantly more caught with floral odours, whereas no differences were observed for parous females. Combining floral and human volatiles did not augment attractiveness. Conclusions Nulliparous and parousA. gambiae s.s.are attracted to combinations of odours derived from spatio-temporally segregated resources in mosquito life-history (floral and human volatiles). This is favourable as mosquito populations are comprised of individuals whose nutritional and developmental state steer them to diverging odours sources, baits that attract irrespective of mosquito status could enhance overall effectiveness and use in monitoring and control. However, combinations of floral and skin odours did not augment attraction in semi-field settings, in spite of the fact that these blends activate distinct sets of sensory neurons. Instead, mosquito preference appeared to be modulated by blood meal experience from floral to a more generic attraction to odour blends. Results are discussed both from an odour coding, as well as from an application perspective.

Keywords

Anopheles gambiae; Mosquito; Attraction; Vectrax; Skin Lure; Volatiles

Published in

Malaria Journal
2020, Volume: 19, number: 1, article number: 318
Publisher: BMC

SLU Authors

• Dekker, Teun

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Zoology


Publication identifier

DOI: https://doi.org/10.1186/s12936-020-03395-2

Permanent link to this page (URI)

https://res.slu.se/id/publ/107877