Figure 7

Results of extended duration bioassays on walls of experimental huts. Percentage mortality of insectary-reared Anopheles arabiensis dondotha following cone bioassay with standard exposure time of one hour (light bars) and extended exposure (darker bars) of two hours (four months), four hours (ten months), 12 hours (17 months) on sprayed mud walls. Mortality for unsprayed walls was <20% for all bioassays.