This paper describes and illustrates females and males of two species of Caenohalictus Cameron, 1903: C. sabanaensis n.sp. and C. alexandrei n.sp. Both species are commonly collected in the Savanna of Bogotá, a high plateau in the central region of the Eastern Andes of Colombia. Notes on morphological variations within and among the species, as well as comments on some biological aspects and images of diagnostic structures are provided.

Phylogeny and taxonomic classification to subgeneric level of Augochloropsis (Hymenoptera: Halictidae). 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. Rev. Biol. Trop. 65 (4): 1277-1306. Epub 2017 December 01.

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.

We revise the bee subgenus Augochloropsis (Glyptochlora) and recognize four species in the group. Three new species are described, Augochloropsis peruviana n. sp., Augochloropsis ticuna n. sp. and Augochloropsis atrocyanea n. sp. and the type species, Augochloropsis ornata (Smith, 1879), is re-described. The descriptions were based on females collected in the Amazon Basin forests from Colombia, Peru, and Brazil. The disjunct distribution exhibited by A. (Glyptochlora) with respect its nearest phylogenetic group Augochloropsis (Glyptobasia), with species only present in the Atlantic Forest of eastern Brazil, is discussed in light of current knowledge about other taxa with similar distribution pattern. This is new evidence for an already well-established pattern of disjunct distributions of some bee taxa between these two biomes. An identification key for the species and a distribution map are also provided.

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