Drasctic loss of insects (Lepidoptera: Geometridae) in urban landscapes in a tropical biodiersity hotspot

Abstract

Abstract: Accelerating urbanization is a particularly important threat to biodiversity in tropical countries. We investigated the diversity and numbers of geometrid moths along a forest-to-urban gradient in a tropical biodiversity hotspot in and around the provincial capital city Loja in southern Ecuador. Moths were collected at different land-use types: forest, forest-pasture, pasture, and urban. We collected a total of 3,064 moths representing 299 morphospecies. Species richness, diversity and numbers of moths drastically decreased along the gradient. Species composition of moth communities in less urbanized localities was strongly different from those collected at most urbanized ones. Floristic composition and degree of urbanization were the main drivers of community differences. Also, different contributions of beta diversity components were found between land-use types depending of degree of disturbance. In sum, moth assemblages in this tropical biodiversity hotspot become severely impoverished throughurbanization. We recommend a more cautious development of urbanized areas in the region through the creation of more green space within the city and the creation of a buffer zone between Loja and adjacent Podocarpus National Park.