Updated checklist of Araneid and Tomisid (Araneae, Araneidae and Thomisidae) species of Comunidad de Madrid: known and potential distribution maps, and richness patterns

Abstract

The list of species of the families Araneidae and Thomisidae in Comunidad de Madrid is updated. 3 new species of Araneidae and 15 of Thomisidae are added to the list, for a total of 30 species in the first family, and of 46 in the second. Heriaeus hirtus and Larinioides cornutus are eliminated from the catalogue. After the distributional and predictive maps were drawn, an significant lack of distributional records is noticed, especially in the Thomisidae due, probably, to their cryptic nature. Richness maps show a common pattern, with maximum values in the Rampa and minimum ones in the south of the province and high altitudes of the Sierra. Although richness scores are probably a sub estimation of true values, the general pattern can be explained according to the ecological preferences of the two families and the spatial pattern of anthropogenic alteration of the habitat in Madrid. The imperative necessity of making field surveys to complete data gaps is highlighted.