Navy Entomology Center of Excellence Jacksonville, Florida, United States
Abstract: From a Force Health Protection perspective, insecticide-impregnated screened panels placed along the perimeter of outdoor/semi-outdoor work areas may provide an additional layer of protection from mosquito vectors. Studies were conducted within a deciduous forest adjacent to a brackish needle grass marsh located at Kings Bay, GA. A 0.4% deltamethrin-impregnated screen material (with untreated screen as a control) was evaluated as open top screen cubes at heights of 3, 2.4, and 1.5 m by 3 m wide (n=4 each) at different time intervals from March 2019 through August 2021. Each cubicle contained a CDC light trap with dry ice. Field results indicated that the majority of mosquitoes collected from all traps were Aedes taeniorhynchus and trapped mosquito counts in 3 m tall untreated cubicles (at 1 wk) were reduced considerably compared with sentinel CDC trap counts. One 3 m tall treated and untreated cubicle was retained as sentinels to monitor reduction by physical exclusion (if present) throughout the 107 wk study while other cubical heights were investigated. We found ≥80% mosquito reduction occurred in 3 m tall deltamethrin-treated screen cubes on 13 of 107 weeks; with 9 time periods attributable to the insecticide (P≤0.05). In treated 2.4 m tall cubes, similar reduction occurred for 7 of 52 wks; the insecticide provided reduction at 4 of those time periods. In 1.5 m tall treated cubicles ≥80% reduction occurred on 5 of 43 wks with insecticide providing reduction at 2 time periods. The deltamethrin screen produced 100% mortality in bioassays against laboratory-reared female Aedes aegypti throughout the study. Data suggests the majority of mosquito reduction in treated cubes was attributed to physical exclusion while the insecticide provided some reduction.