The southern US has a large presence of mosquito vector species for dengue virus (DENV) and experiences thousands of DENV importations every year, which have led to several local outbreaks. Adulticide spraying targeting active mosquitoes is one of the most common insecticide strategies used as a response to an outbreak. The aim of this study is to evaluate the effectiveness of adulticide spraying conducted at different times of the day to curb DENV transmission. Based on unique dataset of Aedes aegypti diel activity patterns in Miami-Dade County, Florida, and Brownsville, Texas, we developed a mechanistic model of DENV transmission, which simulates adulticide spraying interventions. We estimated that spraying adulticide for 14 consecutive days at 7am or 8 pm was highly effective in reducing DENV outbreak probability from 10% in the absence of interventions to 0.1% for Miami-Dade County, and from 7.8 to 0.1% for Brownsville. Moreover, in case of a local outbreak in Miami-Dade County, we estimated the median number of symptomatic infections after the identification of a local outbreak to be reduced from 67.0 (IQR: 25.5–103.0) in the absence of interventions to 1.0 (IQR: 0.0–2.0) when spraying adulticide for 14 consecutive days at 8 pm. In Brownsville, the same intervention is estimated to lead to a decrease from 15.0 (IQR: 7.0–33.0) cases to 1.0 (IQR: 0.0–2.0). Our study highlights the importance of considering diel activity patterns of vector mosquito species in arbovirus preparedness and response planning and provide quantitative evidence to guide the decision-making of mosquito control authorities.

美国南部存在大量登革热病毒 (DENV) 蚊媒物种，每年都会有数以千计的登革热病毒输入，导致多起局部疫情暴发。针对活跃蚊子喷洒杀成虫剂是应对疫情的最常见杀虫剂策略之一。本研究的目的是评估在一天中不同时间喷洒杀成虫剂以遏制登革热病毒传播的有效性。基于佛罗里达州迈阿密戴德县和德克萨斯州布朗斯维尔的埃及伊蚊昼夜活动模式的独特数据集，我们开发了 DENV 传播机制模型，该模型模拟了杀成虫喷洒干预措施。我们估计，在迈阿密-戴德县连续 14 天早上 7 点或晚上 8 点喷洒杀成虫剂，可以非常有效地将 DENV 爆发概率从没有干预的情况下的 10% 降低到 0.1%，将布朗斯维尔从 7.8% 降低到 0.1%。此外，如果迈阿密-戴德县爆发局部疫情，我们估计，在确定局部疫情后，有症状感染的中位数将从不采取干预措施的情况下的 67.0（IQR：25.5–103.0）减少到 1.0（IQR） ：0.0–2.0）当连续 14 天晚上 8 点喷洒杀成虫剂时。在布朗斯维尔，同样的干预措施估计会使病例数从 15.0（IQR：7.0-33.0）减少到 1.0（IQR：0.0-2.0）。我们的研究强调了在虫媒病毒准备和应对计划中考虑媒介蚊种昼夜活动模式的重要性，并为指导蚊虫控制当局的决策提供了定量证据。