This study investigates the nesting habits of Epicharis picta in a nest aggregation located in a fragment of the Atlantic forest in Southeastern Brazil. Ten emergence-traps were set up in this nest aggregation to standardize data collection of phenology, natural enemies, and sex ratio. Epicharis picta nests were in an area of 160 m² with a density of 41 nests/m². Nest and cell architecture are described. Epicharis picta is a protandrous, univoltine species with its emergence in this study occurring between 28 January and 15 April. We provide direct evidence of parasitism on E. picta by Rhathymus friesei, Tetraonyx sexguttata and T. aff. lycoides. The predator Apiomerus lanipes was found to prey Epicharis for the first time. We suggest the use of emergence-traps as tools to support studies of ground-nesting bees. In addition, we compile, update, and discuss data on the nesting biology of all Epicharis subgenera.