Synanthropic spiders’ diversity (Arachnida, Araneae) in the urban zone of Morelia citiy, Michoacan, Mexico. How much does the time of construction of the houses influence?

Spiders have been used to evaluate changes in systems by anthropization effect, some species showing sensitivity to gradual and drastic changes such as urbanization, and other species have been documented as tolerant to this effect. The goal of this work was to describe the change in the spider community in relation to the age of buildings. at the west of Morelia, Michoacán, Mexico. Three categories of construction time and the neighboring vegetation as the pre-urbanization environment were used for comparison. Using direct capture, pit-fall traps and beating nets, 3,619 spiders were collected, and 3,219 (315 males, 630 females and 2,274 immatures) were used for the analysis after removal juveniles that was not possible to identify. A total of 28 families, 93 genera, 47 species and 55 morphospecies were identified. This represents the greatest richness and abundance recorded in urban environments of the country. It describes changes in alpha diversity from colonization in recent constructions to those built 17 years ago. I t was observed that abundance, richness, and diversity decrease with the age of a building, but with high equitability in every age of construction. The age of a building is an important factor for the process of succession in urban environments.