The data presented here comes from samples collected as part of two recent research projects (ISLANDBIODIV and MACDIV), which aimed to understand the drivers of community assembly in Macaronesian islands. We applied the sampling protocol COBRA (Conservation Oriented Biodiversity Rapid Assessment, Cardoso 2009) in ten 50 m x 50 m native forest plots in the Azorean Islands of Pico (6 plots) and Terceira (10 plots) to assess the diversity of spiders species. Through this publication we contribute to the knowledge of the arachnofauna of the Azores, and more specifically, to that of the islands of Pico and Terceira. This dataset presents data generated from spider samples collected in 16 forest plots on the Azorean islands of Pico and Terceira. Of the 40 species collected, 16 were introduced, 13 endemic, seven native (five of them Macaronesian endemics) and four undescribed species. Although most of the species had been previously recorded on both islands, two of the introduced species were recorded in Pico for the first time.

The University of Azores hosts the Azores Bioportal (http://azoresbioportal.uac.pt/) a regional E-Infrastructure. The Azorean Biodiversity Portal (ABP) is an e-infrastructure now associated with Portuguese PORBIOTA and LIFEWATCH. The ABP is a key e-infrastructure for the integrated management of biodiversity data of the Azores, providing a large number of specialized services supporting research, policy and education. The 3000 visits per day, the numerous international scientific collaborations, resulting in publications and academic thesis, and the connection with other prestigious databases demonstrate the Portal’s scientific quality as well as its general appeal. Several Natural History Collections are also managed by University of Azores, namely of Algae, Bryophytes, Vascular Plants, Molluscs and Arthropods.The Azorean Biodiversity Portal shares all the information available on the biodiversity of the Azores, one of the five Macaronesian archipelagos (the other being Madeira, Salvage Islands, the Canary Islands and Cape Verde). Macaronesia is recognized as an important part of the Mediterranean hotspot of biodiversity; however, a comprehensive systematic revision of its biodiversity was still lacking at the end of the 20th century.Based in two European INTERREG IIIB projects, an unprecedented collaboration of more than 200 taxonomists and other scientists resulted in accurate and comprehensive lists of terrestrial species in the Canary Islands (Izquierdo et al., 2001, 2004; Moro et al., 2003), Cape Verde (Arechavaleta et al., 2005), the Azores (Borges et al., 2005b, 2010) and Madeira–Selvagens (Borges et al., 2008). This unique collaboration was fundamental for creating the baseline taxonomic information for the ABP, updating the taxonomic information, listing synonyms.