Biased dispersal of Metrioptera bicolor, a wing dimorphic bush-cricket

In the highly fragmented landscape of central Europe, dispersal is of particular importance as it determines the long-term survival of animal populations. Dispersal not only secures the recolonization of patches where populations went extinct, it may also rescue small populations and thus prevent local extinction events. As dispersal involves different individual fitness costs, the decision to disperse should not be random but context- dependent and often will be biased toward a certain group of individuals （e.g., sex- and wing morph-biased dispersal）. Although biased dispersal has far-reaching consequences for animal populations, immediate studies of sex- and wing morph-biased dispersal in orthopterans are very rare. Here, we used a combined approach of morphological and genetic analyses to investigate biased dispersal of Metrioptera bicolor, a wing dimorphic bush-cricket. Our results clearly show wing morph-biased dispersal for both sexes of M. bicolor. In addition, we found sex-biased dispersal for macropterous individuals, but not for micropters. Both, morphological and genetic data, favor macropterous males as dispersal unit of this bush-cricket species. To get an idea of the flight ability ofM. bicolor, we compared our morphological data with that of Locusta migratoria and Schistocerca gregaria, which are very good flyers. Based on our morphological data, we suggest a good flight ability for macropters of M. bicolor, although flying individuals of this species are seldom observed.

落角约束下的高超声速变体飞行器末制导方法

针对高超声速变体飞行器末段制导问题,提出了一种基于比例控制和预测-校正思想的末制导方法,在满足落角约束的条件下,提升飞行效果。以高超声速飞行器动力学方程为基础、三维偏置比例导引法为框架,构建末制导指令的数学表达。通过实时预测飞行器落角与目标值的偏差,在线校正导引律的偏置项。开展标称条件和任务变更条件下的仿真测试,并在扰动条件下完成蒙特卡洛打靶仿真试验。仿真结果表明,该末制导方法具有较高的制导精度和较强的抗扰动能力,且具有一定的自主性,能够适应任务变更的情况;该制导律发挥了变体飞行器的优势,相比传统飞行器具有更好的末段飞行性能。