CONTROLLING CULICOIDES BITING MIDGES WITH PURPOSE-GROWN VEGETATION BARRIERS IN RESIDENTIAL COASTAL AREAS: AN...

Culicoides biting midges are a major nuisance in coastal residential areas of Australia, yet effective control strategies remain limited. This study evaluated the effectiveness of a residual insecticide treatment applied to a purpose-grown vegetation barrier in reducing biting midge nuisance in adjacent coastal residences, with secondary effects on mosquito abundance also monitored. Biting midge and mosquito populations were monitored continuously using automated smart traps (BG-Counter®) over 18 wk, including 11 wk of pretreatment and 7 wk posttreatment surveillance. During the pretreatment surveillance period, properties adjacent to the vegetation barrier (n = 4) recorded 71% fewer biting midges than nonadjacent properties (n = 2), although this effect was temporally variable (95% confidence interval [CI]: -95% to +55%) and not significant. No reduction in mosquito abundance was observed during the same period. Following treatment of the barrier with a residual insecticide (BiFlex AquaMax®, bifenthrin 100 g/liter), biting midge and mosquito populations declined by 86% (95% CI: 77-92%) and 79% (95% CI: 68-86%), respectively, across the study landscape, including in areas with and without the vegetation barrier. A significant barrier-insecticide interaction for both groups indicated that reductions were greatest in residences adjacent to the vegetation barrier. Decreases in mosquito abundance following application of the residual spray suggests that the vegetation barrier functioned as important harborage habitat, enabling targeted control within and beyond its immediate boundary. These findings support the integration of insecticide-treated vegetation barriers into pest management programs targeting nuisance biting midge and mosquito populations in coastal residential environments.