Model based determination of the influence of textile fabric on bioassay analysis and the effectiveness of a textile slow-release system of DEET in mosquito control Running Title: Influence of textile fabric

BACKGROUND: Determining how effective a product is to repel mosquitoes or other flying insects is a difficult task. One approach is using a bioassay with textile fabric. We investigated the role of the textile substrate in the bioassay with a numerical model, and compared with known results for DEET. We next apply the model to determine the effectiveness of textile slow-release formulations based on coatings, and compare this with a field study in the Cameroon. Slow-release formulations are difficult to evaluate with standard tests as the compound needs a build up time not present in these tests. RESULTS: We found excellent correspondence between the model and the known DEET results without matching parameters. Slow release approaches are deemed possible but have several drawbacks. Modeling can help in identifying optimal use conditions. The field test with a slow release system performed better than the model anticipated with initially more than 90% repellency. DEET coated textile was considered not marketable however. CONCLUSION: We advise that bioassays also characterize more detailed the type of textile fabric used so as to allow drawing conclusions with textile modeling. Concerning coated textile slow release systems, more research is needed. We nevertheless advise usage mainly at entrance points, eg as scrims.