Moulting decisions and the timing of maturation are crucial factors determining the fitness of most arthropods. In spiders, this decisions are different for each sex and depend on the quality of the habitat. Studying the proximate factors influencing this decisions in spiders will be a goal of this research. The semi-permanent structure of the web will enable us to monitor short term decisions of the foraging spider and to relate the morphology of the web to its function. Sophicated engineering methods make it possible to study the physical properties of spider webs in great detail. We will monitor web characteristics and their changes, growth, instar length, number of moults, timing of moults and reproductive success and compare females and males within and between species. We will manipulate the amount and quality of the prey and the web morphology both, in the field and in the laboratory.