Lentic habitats in urban New Orleans consist of permanent lagoons and ponds in the city's public parks, and smaller, temporary puddles that can persist for months after storms. Arthropods found in these puddles consist of those capable of aestivation and those that must colonize from other sources. According to traditional island biogeography models, species richness of islands is determined by distance to the continent from which potential colonizers disperse, and the size of the island. This study examined these tenets in the context of urban aquatic habitats, with a large permanent lagoon in the role of continent, and newly formed puddles from an adjacent neighborhood as islands. The lagoon was sampled for arthropods, and the species richness was estimated. Rain-filled roadside puddles from an adjacent neighborhood were mapped and the size of each puddle was recorded. Arthropods were removed from each puddle in the study area and taken to the laboratory for identification. Species richness in the sampled puddles was correlated with habitat size and distance from the lagoon "continent". A biogeographic model of insect colonization of urban lentic habitats may indicate patterns of arthropods dispersal in other highly fragmented ecosystems. Understanding how proximity to large permanent ponds influences the species composition of small transient pools may enable urban planners, particularly in the rebuilding of New Orleans, to promote biocontrol of mosquito larvae by their natural enemies.