Failure of Interior Residual Sprays as Protection Against Mosquitoes in Military-Issued Two-Man Tents

Most studies on interior (or indoor) residual spraying (IRS) have been targeted on permanent/semiper- manent structures. We measured the utility of a portable fi eld bioassay, which can be set up quickly to determine the best chemical repellent or irritant for use as an IRS during an emergency or military situation when displaced persons are tem- porarily housed in tents. If the bioassay were used over an extended period of time, it would also offer a unique way to monitor vector susceptibility and would be able to determine which chemical is most effi cient in individual populations. In total, 2,193 mosquitoes belonging to seven species in figenera were collected over the study period. No statistical differences were found between any of the treatments, control, and standard tents utilizing the 4 × 4 Latin square design. Therefore, we conclude that IRS with these tested chemicals in military-issued two-person tents are not effective or sig- nifi cant at stopping mosquito entrance. Further studies on implementation of a portable, fi eld bioassay should include utilizing different mosquito traps in the bioassay and looking at the difference between contact irritants and spatial repel- lents in different-sized tents, as spatial repellency may be more important in smaller-sized tents.