Abstract In Colombia, few studies have focused on nest architecture, behavior or sociality of wild bees. This study provides basic information on the nests of Caenohalictus alexandrei and presents behavioral observations outside the nests, derived from direct field observation of 40 nests and 39 male sleeping cavities in two localities of the Savanna of Bogota, Colombia. We recognized four different behavioral activities carried out by adult females: foraging, guarding, opening and closing of the entrance of the nest, with foraging being the most frequent of them. The observed activities were carried out more frequently from 9:00 h to 13:00 h. Males were observed performing two behavioral activities in the sleeping cavities: staying at the cavity entrance and cavity departure. A third male activity, corporal grooming, was carried out outside the sleeping cavity. Our field observations indicate that more than one adult female was active simultaneously performing the different tasks within a single nest. The nests presented different levels of complexity in their architecture, depending on the age of the nest and number of adult females in them. Descriptions of the nesting sites and behavioral activities as well as illustrations of the nest architecture are provided.

Resumen Augochloropsis Cockerell, 1897b es un grupo altamente diverso en el Neotrópico, comúnmente recolectado en inventarios faunísticos en áreas silvestres. Estas abejas generalmente quedan sin identificar en las colecciones pues las claves taxonómicas y las descripciones originales son limitadas y no permiten la separación ni siquiera a nivel subgenérico. El objetivo de este estudio fue realizar la filogenia y la revisión taxonómica del género Augochloropsis, a nivel de subgénero, partiendo del examen detallado de 56 caracteres morfológicos de 2 433 ejemplares. Cuatro subgéneros son reconocidos y descritos de forma detallada: (Augochloropsis s. str. (Cockerell, 1897b) (Paraugochloropsis Schrottky, 1906 ((Glyptochlora Moure, 1958) (Glyptobasia (Moure, 1941)))). Se aportan fotografías sobre los caracteres morfológicos externos, ilustraciones de la cápsula genital y de los esternos metasomales SIII-SVIII del macho, así como una clave de identificación taxonómica a nivel subgenérico y mapas de distribución geográfica.

Abstract Augochloropsis Cockerell, 1897b is a highly diverse group in the Neotropics and commonly collected in wildlife surveys. These bees remain mostly unidentified in collections because of the lack of taxonomic keys and the incomplete original descriptions, which prevent sorting specimens even at the subgeneric level. The aim of this study was to perform the phylogeny and the taxonomic revision of the genus Augochloropsis to subgeneric level, based on a detailed examination of 56 morphological characters of 2 433 specimens. Four subgenera are recognized and described in detail: (Augochloropsis s.str. (Cockerell, 1897b) (Paraugochloropsis Schrottky, 1906 ((Glyptochlora Moure, 1958) (Glyptobasia (Moure, 1941)))). Photographs of external morphological characters, illustrations of the male genital capsule and the metasomal sterna SIII-SVIII are provided, as well as a taxonomic key to subgenera and distribution maps.