The species of Lasioglossum from Greater Puerto Rico are reviewed. Nine species are recognized, including five new species described herein: Lasioglossum (Dialictus) genaroi sp. nov., L. (D.) dispersum sp. nov., L. (D.) enatum sp. nov., L. (D.) monense sp. nov. and L. (D.) amona sp. nov. The latter two are known only from Mona Island. Keys and images are provided to assist in identification. Details of nesting biology, floral hosts and distribution are provided where available. Three species, L. (D.) parvum (Cresson, 1865), L. (D.) busckiellum (Cockerell, 1915), and L. (D.) mestrei (Baker, 1906) are removed from the list of species for Puerto Rico. Details on their revised distribution are provided. Three new records for Haiti, L. (D.) gundlachii (Baker, 1906), L. (D.) ferrerii (Baker, 1906) and L. (D.) busckiellum are documented. Notes on other species in the Greater Antilles are provided, including the synonymy of Lasioglossum bruesi (Cockerell, 1912) and L. jamaicae (Ellis, 1914) under L. gemmatum (Smith, 1853).
Apoidea, distribution, new species, synonymy, taxonomy.