Proportion of mosquitoes dying within 24 hours after exposure to 0%, 1% or 2% DDT. Exposures occurred on 10 days (left) or 19 days (right) after blood feeding on mice infected with Plasmodium. The diamonds represent mosquitoes that had fed on an uninfected mouse (open diamonds) and those fed on an infected mouse (solid diamonds). The squares consider only the mosquitoes fed on an infected mouse, and represent those in which we found parasites (solid squares) and those that had no parasites (open squares). The vertical lines show the 95% confidence intervals of the proportions.