Supplementary material from Flight behaviour of malaria mosquitoes around odour-baited traps: capture and escape dynamics.

Host-seeking mosquitoes rely on a range of sensory cues to find and approach blood hosts, as well as to avoid host detection. By using odour blends and visual cues that attract anthropophilic mosquitoes, odour-baited traps have been developed to monitor and control human pathogen-transmitting vectors. Although long-range attraction of such traps has already been studied thoroughly, close-range response of mosquitoes to these traps has been largely ignored. Here, we studied the flight behaviour of female malaria mosquitoes (Anopheles coluzzii) in the immediate vicinity of a commercially available odour-baited trap, positioned in a hanging and standing orientation. By analysing more than 2500 three-dimensional flight tracks, we elucidated how mosquitoes reacted to the trap, and how this led to capture. The measured flight dynamics revealed two distinct stereotypical behaviours: (i) mosquitoes that approached a trap tended to simultaneously fly downward towards the ground; (ii) mosquitoes that came close to a trap changed their flight direction by rapidly accelerating upward. The combination of these behaviours led to strikingly different flight patterns and capture dynamics, resulting in contrasting short-range attractiveness and capture mechanism of the oppositely oriented traps. These new insights may help in improving odour-baited traps, and consequently their contribution in global vector control strategies.

寻宿主蚊虫依赖多类感官线索定位、接近血液宿主，同时规避宿主的侦测。研究人员借助可吸引嗜人蚊虫的气味混合物与视觉线索，开发出诱蚊诱捕器（odour-baited traps），用于监测并防控传播人类病原体的媒介生物。尽管此类诱捕器的长程引诱效果已被充分研究，但蚊虫对诱捕器的近程响应却长期被忽视。

本研究针对两种安装姿态（悬挂式与立式）的商用诱蚊诱捕器，探究了雌性疟蚊（按蚊Anopheles coluzzii）在诱捕器近场的飞行行为。通过分析超过2500条三维飞行轨迹（three-dimensional flight tracks），我们阐明了蚊虫对诱捕器的响应机制，以及该响应如何介导蚊虫被捕获的过程。

实测的飞行动力学数据揭示了两类截然不同的典型行为模式：其一，接近诱捕器的蚊虫会伴随向地面俯冲的飞行趋势；其二，贴近诱捕器的蚊虫会通过快速向上加速来改变飞行方向。这两种行为的组合造就了差异显著的飞行模式与捕获动力学过程，进而使得两种安装姿态的诱捕器呈现出相反的近程吸引力与捕获机制。

本研究的新发现可为优化诱蚊诱捕器性能提供理论支撑，进而助力其在全球媒介生物防控策略中发挥更显著的作用。