Polar cuticular lipids differ in male and female sand flies (Phlebotomus papatasi)

The polar cuticular lipids of the Old World sand fly, Phlebotomus papatasi, were analyzed by high resolution mass spectrometry.  Blood-fed females, non-blood-fed females and males were separately analyzed and compared. The major polar cuticular lipids were found to be long-chain diols and fatty acids. Relatively high levels of diacylglycerols were found in blood-fed females and in males. A wide variety of  lipids were found at low levels, including esters, sterols, monoacylglycerols, and hydroxy fatty acids. Blood-fed females had several lyso lipids and N-acyl amino acids that were not found on unfed females or males. These substances may be surfactants used in blood-feeding.  Heneicosanoic acid was found on females at more than twice the level of males, suggesting it could be a component of a previously-described female aggregation pheromone. Four substances were identified on males at two-fold higher levels than on females: tetradienoic acid, methoxyhexadecasphinganine, butyl octadecanoate, and DG(14:1/12:0/0:0). These could be short-range pheromones involved in courtship. The potential aggregation and courtship pheromones will be further analyzed in future behavioral bioassays.