Spiders along with insects comprise over two-thirds of the planet’s biodiversity. At a time where habitats are being rapidly cleared, many species become extinct before even being discovered, and of those recorded, little or nothing is known of their ecology or behavior, especially with respect to Neotropical species. In this series of studies, the major focus is on the pholcid Mesabolivar aurantiacus, and the relationships between its favoured microhabitat, and the other arthropods it shares this space with, including, conspecifics, the orb-weaving spider Azilia vachoni, and the nabid bug Arachnocoris trinitatus which is found in its webs. These relationships were examined through observational studies, disturbance and removal experiments. Notes on the web structure of the pholcid Physocyclus globosus and an aggregation of the semi-social mygalomorph Ischnothele caudata are also included. Therefore, it is expected that these studies will serve to fill the gap in knowledge of the spider fauna of this region and will be useful to the nature enthusiast and scientist alike in learning about the ecology and behaviour of some of this region’s unique spider fauna.