Which vector control strategy is typically used to reduce indoor adult mosquito populations?

• A. Indoor residual spraying
• B. Environmental management to remove breeding sites
• C. Larvividing
• D. Bed nets and repellents

Answer: (A)

Indoor residual spraying directly targets adult mosquitoes that rest inside homes by applying a long-acting insecticide to interior surfaces. This approach increases the likelihood that indoor-resting adults encounter the chemical and die, leading to a measurable drop in the indoor mosquito population and, consequently, transmission potential. It works best for species that tend to rest indoors after feeding and when coverage is sufficiently high to create a community-wide impact.

Other options focus on stages other than indoor adults or on personal protection rather than reducing indoor adult density. Removing breeding sites and larvividing cut the future adult population at the source by targeting larvae, not the currently living indoor adults. Bed nets and repellents mainly reduce the risk of bites and may modestly influence indoor mosquitoes, but they do not primarily reduce the number of adult mosquitoes inside homes.