I work for a company which tests, among other things, repellents and insectides. We have run a modified version of the WHO tunnel test at our institution before (which excludes the animal component) but the glass tunnels are hazardous and difficult to work with. I've had a design built and tested in the past with untreated netting which is made of acrylic, but have had queries raised on whether acrylic plastic can absorb insecticides, and leave with a residual effect. The insecticide would only be on fabric or netting, not sprayed on the actual tunnel, but there would likely be a bit of transfer from mosquitoes contacting the net and then the walls of the tunnel. Anyone have any knowledge of chemistry who might be able to answer this, preferably with a reference?