Sand fly blood meal volumes and their relation to female body weight

Abstract

Background Sand fly females took a blood meal to develop eggs. The size of the blood meal is important for the fecundity but also affects the dose of pathogens acquired by females while feeding on infected host or during experimental membrane-feeding experiments. Methods Under standard laboratory conditions we compared blood meal volumes taken by females of ten sand fly species belonging to four genera: Phlebotomus, Lutzomyia, Migonomyia and Sergentomyia. Amount of ingested blood was determined by haemoglobin assay. In addition, we weighted unfed sand flies to calculate a ratio between body weight and blood meal weight. Results The mean blood meal volume ingested by sand fly females of different species ranged from 0.47 to 1.01 µl. Five species studied, Phlebotomus papatasi, P. duboscqi, Lutzomyia longipalpis, Sergentomyia minuta and S. schwetzi took about double size blood meal in comparison to Migonomyia migonei. In females, the mean body weight ranged from 0.183 mg in S. minuta to 0.369 mg in P. duboscqi. In males, the mean body weight ranged from 0.106 mg in M. migonei to 0.242 mg in P. duboscqi. Males were always lighter than females, the ratio between sexes ranged from 75% in P. argentipes to 52% in P. tobbi. Conclusions Interspecific analysis did not reveal any correlation between mean blood meal volume/weight and the mean weight of females (M_bl/M_f). Most species took a blood meal 2.25–3.05 times higher their body weight. Relatively tiny females of P. argentipes took 3.34 times their body weight. The highest (M_bl/M_f) ratio was found in both Sergentomyia species studied; females of S. minuta and S. schwetzi took bloodmeals 4,5–5 times higher than their body weight. This parameter is substantially higher then reported for any mosquitoes and biting midges.