Large-Scale Deployment of Lehmann’s Funnel Entry Traps to Control Malaria Mosquito Populations

Abstract

Effective tools to prevent mosquito bites are essential for malaria control. The Lehmann Funnel Entry Trap (LFET), a window screen proven effective in reducing mosquito density, was tested for its large-scale impact on malaria vector control and community acceptance. A total of 1313 traps were deployed in Vallée du Kou 3 (VK3), with 12 traps randomly selected for detailed evaluation against untrapped houses in Vallée du Kou 5 (VK5). Traps were placed in windows with doors blocked by curtains. From July to October, mosquitoes were collected for nine days per month from VK3 traps and VK5 control houses. Morphological identification, density analysis, resistance gene screening, and female age structure determination were conducted. The trap's impact was assessed via pyrethrum spray catch (PSC) and for nine days per month, while trap fabric integrity and community perceptions were also evaluated. Traps reduced mosquito entry density by more than 90% in VK3 houses. VK3 had 33% higher house mosquito density pre-intervention and 47% lower house mosquito density post-intervention than VK5. Old female mosquito numbers rose in VK5 but not VK3. Pyrethroid resistance was high (kdr mutation frequency > 0.9) in both control and intervention sites. VK3 residents appreciated the traps for reducing bites and improving sleep. The LFET effectively controls malaria vectors and is well-suited for widespread use in malaria elimination efforts.