Effect of Leishmania infection on sand fly survival after oral challenge with Serratia marcescens . (A) Survival of female Lu. longipalpis containing Leishmania after oral challenge with Serratia marcescens in sucrose (diamond) in comparison with insects fed with a bloodmeal containing Serratia (square), Leishmania (triangle), or blood followed by sucrose (circle). **P ≤ 0.0001; Chi-square 96.987 (Log Rank-Mantel Cox). (B) Scatter plot showing Leishmania promastigote population, at day 3, within individual sand fly midguts after subsequent feeding with 20% w/v sucrose or a Serratia marcescens suspension (5.7 × 107 CFU mL-1) via cotton wool.