180 - Attraction of sand fly larvae Phlebotomus papatasi to larval feeding media and investigation of chemoattractants

Phlebotomine sand flies are important vectors of pathogens of medical importance, such as the Leishmania parasites responsible for 700,000 – 1 million new cases of leishmaniasis every year. For developing novel and targeted vector control tools it is important to improve our understanding on the ecology of sand flies across all different stages of their development. While there are numerous studies investigating attraction and oviposition preferences of adult sand flies, the ecology of larvae remains comparatively less known. The aim of this study was to explore the effect of different larval feeding media in attracting sand fly larvae.  Two different bioassays were conducted a) a no-choice and b) a choice bioassay. No choice assays were used to determine the optimum time when 90% of the sand fly larvae reaches the standard feed mixture in comparison with the control (the pot with no feed). At the optimum time the majority of the larvae were found in the standard food. The choice assays were used to compare the feeding preferences between the standard feed medium, and other feeding substrates. Gas chromatography mass spectroscopy (GC-MS) equipped with the automated headspace (HS) system was applied to determine differences between the molecular compositions of the study materials, and by eliminating the identical components, identify molecule(s) that possibly produce the feeding attraction. These attractant molecules could be used to improve larviciding treatments  by increasing contact of the larvae with insecticide, or/and as the lead structures for development of new active compounds.