The effect of chicken blood on Leishmania development in sand fly midguts: 6 days after infection. Six days after the infection by promastigotes in 10% rabbit blood (106 parasites/ml) P. duboscqi females were allowed to feed on chickens or mice. Infection rates and intensities of infection were evaluated in sand fly midguts on days 2 and 6 after the second bloodmeal. A: Intensities of infection were microscopically classified into three categories: light (< 100 parasites/gut), moderate (100–1000 parasites/gut), or heavy (> 1000 parasites/gut). Numbers above the bars indicate the number of dissected females. B: The precise number of parasites from 50 females of both groups was measured by Q-PCR 6 days after the second bloodmeal.