15 - Treating outside the box, using spatial models to define adulticide treatment surfaces

Integrated mosquito management relies on surveillance data including species abundances and infection status from mosquito traps to define control actions. Given limitations of sample size due to the resource-intensive nature of mosquito trapping, inferences of mosquito abundance across space and time likely result in considerable error and therefore imprecise insecticide applications. St. Tammany Parish Mosquito Abatement makes daily decisions to conduct ultra-low volume adulticide applications to static “zones”, polygon areas defined by road networks. Currently, treatment decisions are driven by mosquito abundances exceeding thresholds or the presence of arbovirus-infected mosquitoes from single trap nights within each zone. Interpolated spatial models can estimate mosquito abundance across unsampled space to create a “surface” of mosquito abundance. Since these estimates are created by weighting abundance from a network of multiple sites instead of inferring from just one, theoretically they should result in more precise treatments. Treatment “need” surfaces are no longer static polygons but become “blob-like”, creating new logistic challenges. In addition to improving treatment precision to areas of need, novel outcome metrics including estimating number of mosquitoes reduced, number of people served, and treatment costs allow for improving cost efficiency.