Behavioral, microbial, and chemical ecology of sand fly oviposition site selection

Grant Number: 1R01AI180067 - 01A1 PI PI Name: Wasserberg, Gideon University of North Carolina at Greensboro Phlebotomine sand flies are vectors of the protozoan agents of human leishmaniases, as well as various bacterial and viral pathogens associated with neglected tropical diseases. Unlike most biting Diptera, sand flies have a fully terrestrial life cycle. For Phlebotomus papatasi, the most important vector of Leishmania major in arid areas of the Old World, the burrows of its gerbilline host are critical for shelter and breeding and therefore constitute a weak and exploitable link. The critical dependency of P. papatasi on its rodent host and burrow represents a tightly coupled vector-host system, and possibly a resource-based mating system. We hypothesize that elements within the burrow, including the host, its decomposing feces, saprophytic microbes, and some juvenile and adult stages provide a highly attractive environment not only for gravid females but also to host- and mate-seeking females and males. We predict that multiple chemical and biological cues converge within the burrow environment to guide host location, mate finding, and egg-laying behavior. By integrating lab and field studies, our goal is to test the resource-based attraction hypothesis and investigate the microbial and chemical mechanisms underlying it. Our long-term goal is to leverage these cues to develop an attractive lure, and ultimately an attractive lethal oviposition trap, for P. papatasi. No such tool currently exists, and targeting gravid females could be particularly impactful for reducing vector populations and interrupting pathogen transmission.