10: Identification of bacterial odors from oviposition substrates to control sand fly populations

Sand flies (Diptera: Psychodidae) are vectors of protozoan parasites that cause human leishmaniases, which following malaria and dengue, are the most pervasive vector-borne diseases. Leishmaniases are found in warm tropical, semi-arid, and arid environments. With no vaccine against the etiologic agent, reduction of exposure to sand fly bites is the most effective prevention measure with spraying of insecticides being a common approach. However, this method is highly variable and can affect a wide range of non-target organisms. Therefore, it is critical to develop a sustainable control method for this neglected disease vector. Chemical attractants from oviposition sites can provide the basis for a novel targeted surveillance technology. Hence, the aim of this project is to identify specific metabolites that serve as oviposition site attractants, repellents or oviposition stimulants for the sand fly, Phlebotomus papatasi, using a stepwise approach combining chemical, electrophysiological and behavioral techniques. We collected odors from natural attractive sources, such as conspecific materials and microbes isolated from oviposition substrates, and analyzed them by gas chromatography coupled to mass spectrometry. Biologically-active odorants were discriminated from non-active compounds using electrophysiological recordings from sand fly antennae. After identifying all bioactive odorants and the respective behavioral responses from sand flies, field traps that emit volatile attractants will be used to control sand fly populations and avoid capturing non-target organisms.