Scale-free olfactory-driven foraging

当风把气味分子从源头吹散时，气味羽流就形成了。许多种类的昆虫可以沿着气味羽状物找到它们的来源，寻找配偶或远处的资源。许多重要害虫种类的信息素和调节昆虫行为的化学物质现已被鉴定、合成和配制，用于害虫管理计划，并广泛用于种群监测的陷阱。然而，尽管进行了大量的研究，但在这些应用中，符号化学物质并没有普遍成功。在某种程度上，这是因为对气味扩散的详细了解，即气味来源和分布、大气条件和害虫行为反应之间的相互作用，在很大程度上仍然未知。本提案将通过制定和验证在气味羽流中飞行的昆虫所经历的气味浓度的新数学模型来解决这一缺点。这是一个相当大的挑战，因为气味浓度在广泛的空间和时间尺度上表现出复杂、混乱的进化结构。事实上，气味浓度的波动是自然界中发现的最极端的波动形式之一。这些新的气味浓度数学模型将与昆虫反应模型相结合，用于预测昆虫的运动模式。据推测，观察到的昆虫觅食模式的复杂性源于昆虫对气味浓度复杂模式的幼稚反应。这与广泛持有的观念形成了对比，即昆虫的复杂行为，通过进化过程，导致了最优或有利的搜索策略。然后，该模型将与未来的实验同时使用，以便更好地了解化学生态学和病虫害管理的其他方面。例如，该模型可以用来评估吸引信息素的单个组成部分和其他符号化学物质在多大程度上可以调节源位置的早期行为，如锁定羽流，以及后来的行为，如着陆或求爱。该模型还可用于确定诱捕器的有效范围，并将诱捕器的数量与空气中人口的密度联系起来——这是一个对人口监测具有相当实际重要性的问题，因为诱捕器的数量往往与密度没有很好的相关性。

Scent plumes form when the wind disperses scent molecules from their source. Many species of insects can follow scent plumes to their sources to find mates or distant resources. The pheromones of many important pest species and semiochemicals that mediate such insect behaviour have now been identified, synthesized, and formulated for use in pest-management schemes and are used widely in traps for population monitoring. However, despite considerable research semiochemicals have not been universally successful in these applications. This is, in part, because the detailed understanding of scent dispersal which underlies the inter-play between sources and distributions of scent, atmospheric conditions and pest behaviour responses remains largely unknown. This proposal will address this shortcoming by formulating and validate new mathematical models for the scent concentration experienced by insects flying within scent plumes. This is a considerable challenege because scent concentrations exhibit a complex, chaotically evolving structure over a broad range of spatial and temporal scales. Indeed, fluctuations in scent concentrations are amongst the most extreme form of flcutuations found in Nature. These new mathematical models of scent concentration will be combined with models of insect response and used to predict insect movement patterns. It is hypothesised that the observed complexity of insect foraging patterns arises from naive insect responses to the complex patterns in scent concentrations. This constrasts with the widely held notion that the complex behaviour of insects has, through the process of evolution, resulted in optimal or advantageous searching strategies. The model will then be used in parallel with future experimentation to provide a better understanding of other aspects of chemical ecology and pest-management. The model could, for example, be used to assess the extent to which the individual components of attractive pheromones and other semiochemicals can mediate the earliest behaviours in source location, such as locking onto a plume, and later behaviours, such as landing or courtship. The model could also be used to determine the effective extent of traps and relate trap counts to densities of airborne population--a problem of considerable practical importance for population monitoring because trap counts often do not corelate well densities.