Data from: Comparative system identification of flower tracking performance in three hawkmoth species reveals adaptations for dim light vision

Flight control in insects is heavily dependent on vision. Thus, in dim light, the decreased reliability of visual signal detection also prompts consequences for insect flight. We have an emerging understanding of the neural mechanisms that different species employ to adapt the visual system to low light. However, much less explored are comparative analyses of how low light affects the flight behaviour of insect species, and the corresponding links between physiological adaptations and behaviour. We investigated whether the flower tracking behaviour of three hawkmoth species with different diel activity patterns revealed luminance-dependent adaptations, using a system identification approach. We found clear luminance-dependent differences in flower tracking in all three species, which were explained by a simple luminance-dependent delay model, which generalized across species. We discuss physiological and anatomical explanations for the variance in tracking responses, which could not be explained by such simple models. Differences between species could not be explained by the simple delay model. However, in several cases, they could be explained through the addition on a second model parameter, a simple scaling term, that captures the responsiveness of each species to flower movements. Thus, we demonstrate here that much of the variance in the luminance-dependent flower tracking responses of hawkmoths with different diel activity patterns can be captured by simple models of neural processing.昆虫的飞行控制高度依赖视觉。因此，在低光照环境中，视觉信号检测可靠性的下降会对昆虫飞行产生负面影响。目前学界对不同物种适配低光照视觉系统所采用的神经机制已有愈发深入的认知。然而，针对低光照如何影响昆虫物种飞行行为，以及生理适应与行为间对应关联的比较分析，仍鲜有开展。本研究采用系统辨识（system identification）方法，探究三种具有不同昼夜活动模式的天蛾（hawkmoth）物种的花追踪行为是否存在亮度依赖的适应性特征。研究发现，三种天蛾均表现出显著的亮度依赖型花追踪行为差异，且该差异可通过一个跨物种通用的简单亮度依赖延迟模型得以解释。本研究还探讨了追踪响应差异的生理与解剖层面的潜在解释——这类差异无法通过上述简单模型阐释。不同物种间的行为差异无法由该简单延迟模型解释，但在多数情况下，通过新增第二个模型参数，即用于表征各物种对花运动响应敏感性的简单缩放项，即可对该差异作出合理解释。综上，本研究证实：针对具有不同昼夜活动模式的天蛾，其亮度依赖型花追踪响应的大部分差异，均可通过简单的神经处理模型予以刻画。