Data from: Investigating movement in the laboratory: dispersal apparatus designs and the red flour beetle, Tribolium castaneum

The natural dispersal of Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) has been emulated in the laboratory for more than 50 years, using a simple dispersal apparatus. This has typically comprised of a starting container (initial resource or patch) connected by tubing, which contains thread for the animals to climb into a tube and hence to an end container. That is, beetles move to a new viable resource or patch from an inter-patch zone or non-viable habitat. We modified this basic apparatus design to test the effect of tubing length and tubing insertion angle on the dispersal rate and proportion of successful dispersers. We expected that the proportion of successful dispersers would be repeatable within each apparatus design, and that increasing tubing length and steepness of the insertion angle would reduce dispersal rate and success across apparatus designs. Dispersal increased linearly through time, similarly so for both males and females. The design with the most vertical tubing insertion angle had a lower proportion of successful dispersers. Tubing length also had a negative relationship with dispersal success (as judged by insects reaching the end container), but a significant reduction in dispersal success was only apparent between the shortest and longest tubing between containers. We suggest that locating and climbing the vertical section of string before they can enter the tubing between containers restricts dispersal and that at higher densities, insects exhibit greater inclination to climb. This type of apparatus has flexible design tolerances and further potential to study the dispersal of other small insect species that primarily use pedestrian locomotion.赤拟谷盗（Tribolium castaneum Herbst，鞘翅目Coleoptera：拟步甲科Tenebrionidae）的自然扩散行为，已借助简易扩散装置在实验室中被模拟研究达50余年。该装置通常由起始容器（初始资源斑块）与连接管路组成，管路内铺设棉线供昆虫攀爬，进而通过管路进入末端容器。简言之，该装置模拟了甲虫从斑块间区域或不适生境迁移至新的可利用资源斑块的过程。本研究对该基础装置的设计进行改良，以探究管路长度与管路插入角度对扩散速率及成功扩散个体比例的影响。我们预期，同一装置设计下的成功扩散个体比例具备可重复性；且随着管路长度增加与插入角度陡增，不同装置设计的扩散速率与扩散成功率均会降低。扩散行为随时间呈线性增长，雄性与雌性个体均表现出该规律。管路插入角度最接近垂直的装置，其成功扩散个体的比例更低。管路长度与扩散成功率（以抵达末端容器的昆虫数量为判定标准）呈负相关关系，但仅在容器间最短与最长管路组之间，扩散成功率才出现显著下降。我们推测，昆虫需先定位并攀爬垂直棉线段才能进入容器间的管路，这一过程限制了扩散行为；而在种群密度较高时，昆虫的攀爬意愿会更强。该类装置具备灵活的设计容错空间，且可进一步用于探究其他主要依靠步行运动的小型昆虫的扩散行为。