Quantifying long-range migration in Lepidoptera: integrating population dynamics and flight behaviour

众所周知，一些常见的英国蝴蝶(如大白蝶和小白蝶)和飞蛾(如银色Y蝶)会进行长距离的季节性迁徙，有时会超过数百公里。这些蝴蝶和蛾子是其活动范围南部(南欧)农作物的害虫，随着气候变暖，它们可能会在未来大量迁徙到英国，成为重要的害虫。然而，我们仍然远未理解这些运动是如何实现的。例如，所有早期的观测都非常接近地面，所以我们对物种通常飞行的高度知之甚少，也不知道这些高度的风是否正朝着物种试图达到的方向吹。同样，如果风吹过蝴蝶和飞蛾，我们不知道它们在靠近地面飞行时是否能控制它们的飞行方向。我们会使用两种特别为研究昆虫迁徙而设计的雷达，调查蝴蝶和飞蛾是否选择在特定的时间和高度飞行，以便它们能利用有利的风向帮助它们向最有利的方向迁徙。我们还将使用专门建造的飞行模拟器，在那里，被拴住的昆虫可以随意选择飞行方向，以测试季节因素(如白天的时间)或幼虫的饲养条件(如过度拥挤或缺乏食物)对促进迁徙飞行更重要。最后，我们将评估迁徙如何影响英国选定物种的种群规模，以及这种影响在气候变化的影响下可能会如何变化。

Some common British butterflies (e.g. the Large White and Small White) and moths (e.g. the Silver Y) are known to make long-distance seasonal migrations, sometimes over hundreds of kilometres. These butterflies and moths are pests of agricultural crops in the south of their range (southern Europe), and with climate warming they may migrate to the UK in greater numbers in the future and become important pests. However, we are still far from understanding how these movements are achieved. For example, all earlier observations have made very close to the ground , so we know very little about the heights at which the species generally fly, nor whether the wind at these heights is blowing in the direction that the species are trying to tarvel. Equally, we don't know if the butterflies and moths can control their flight direction when they are flying near the ground if the wind is blowing acros them. We will use two types of radar specially-designed for studying insect migration to investigate whether the butterflies and moths choose to fly at particular times and heights so that they can use winds blowing in a favourable direction to help them migrate in the most advantageous direction. We will also use purpose-built flight simulators, where a tethered insect can choose its flight heading at will, to test whether seasonal factors (such as the hours of daylight) or larval rearing conditions (such as overcrowding or a lack of food) are more important in promoting migratory flight. Finally, we will assess how migration affects the population sizes of the selected species in the UK, and how this is likely to change under the influence of climate change.