Net regeneration studies are conducted as part of net quality control assessments to evaluate their durability. Washing removes insecticide from the surface of a net, however the insecticide migrates back to the surface and is replenished. The ‘regeneration time’ is the time required to restore an effective amount of insecticide on the surface of the net.
To determine regeneration time, cone bioassays are conducted on the unwashed net first, then the net is washed and dried 3 times using standard procedures, and cone bioassay conducted on the washed net on days 1, 2, 3, 5, 7 after washing. The mortality recorded after each cone assay is used to obtain efficacy curves from which the regeneration time is extrapolated.