Euglossa Latreille, 1802 do not live in large colonies, and these are usually maintained or “reactivated” by new females, subordinate to their mother, which construct and provision brood cells. This study aimed to obtain information about the natural history of Euglossa cordata (Linnaeus, 1758) specially focusing on nest behavior. Our specific objective was to answer the following question: do E. cordata females reside in a single nest? We construct 14 artificial nesting boxes and made them available for E. cordata bees in natural environment for seven months. During this time, we use a re-marking method to identify bee fidelity to a single nest box. More specifically, we record bee permanence in the nests, the time bees take to provision brood to new cells and the time taken to offspring emergence. A total of 12 boxes were colonized by E. cordata and 23 cells were built in an average of 9.78 ± 11 days per cell. Eleven females emerged from the cells in 48.6 ± 11 days. Although adult females moved between nests and sometimes used multiple nests at the same time, E. cordata showed a relatively high fidelity to a single nest (81.1% of the female bees stayed in a single nest more than 50% of time).

Tetrapedia diversipes Klug (Apidae) is a solitary bee with wide geographical distribution. Females of this species usually nest in pre-existing cavities and although their biology is relatively well known, studies on their trophic niche are still scarce. Thus, the present study aimed to identify the plant species used in the diet of immature T. diversipes through the analysis of residual pollen material. The nests used in the study were obtained through the use of trap nests during the period between December 2014 and October 2015, distributed in an area of coastal forest in northeastern Brazil. For the study of the trophic niche, samples of post-emergency residue (feces) from cells of offspring of males (n = 31) and females (n = 66) of T. diversipes were analyzed. In total, 29 pollen types were identified in the feeding of T. diversipes, being of the pollen types identified, only seven were not used by both sexes. Although a significant difference was found in the amplitude in the trophic niche between the sexes, there was a high overlap for Horn-Morisita index (CH = 0.989), with no significant difference being found in the frequency distribution of male and female food items (D = 0.214; p = 0.341). In this study we concluded that the diet of T. diversipes in coastal forest is polyletic, similarly to the pattern found in other studies of pollen resources in different vegetation in Brazil, with a predominance of pollen from the families Euphorbiaceae, Asteraceae and Onagraceae.