Oxytrigona mellicolor

Oxytrigona mellicolor (Packard, 1869) (Figure 4) Trigona mellicolor Packard, 1869: 56, holotype female worker (MCZ, examined through photographs available at https:// mczbase.mcz.harvard.edu/guid/MCZ:Ent:559), from Ecuador. Oxytrigona huaoranii Gonzalez & Roubik, 2008: 59, holotype female worker (USNM), from Napo, Ecuador; 55 paratype female workers (SEMC, STRI, RPSP, examined). New synonym. Comments. The species was described based on material collected between Quito and the Napo River in Ecuador (Packard 1869). Even though Camargo et al. (2023) and the MCZ database label the type material as “ syntype ”, only a single female worker is recorded in the literature (Figure 4, see also Cockerell 1907, Schwarz 1948). There is no indication in the original description of the species that there is more than one specimen attributed as type material. Therefore, I assume that the single specimen available in the MCZ database (MCZ 559) corresponds to the holotype (as also suggested in Camargo et al. 2023). Historically, O. mellicolor is interpreted as a species widely distributed on the northwestern slope of the Andes, ranging from southern Ecuador to northern Guatemala (Camargo et al. 2023). However, this interpretation is probably incorrect, as the Napo River runs east from the Andes, being a tributary of the Amazonas River. Examining the holotype, it is possible to identify characters used in the diagnosis of O. huaoranii by Gonzalez & Roubik (2008), such as the short fore femur with strongly curved ventral margin. Based on the description and comparisons with the paratype specimens deposited at RPSP (see figure 57 in Almeida et al. 2020), it becomes clear that O. huaoranii is a junior synonym of O. mellicolor. Specimens identified as O. mellicolor from the western side of the Andes and Central America, in fact, belong to an undescribed species, which is accounted for below. Oxytrigona mellicolor is, therefore, a species with restricted distribution, only recorded for the humid region of Napo, Ecuador. I also conclude that the type series of O. mellicolor is not mislabeled as previously suggested by Camargo & Pedro (2007). Diagnosis. The species is the only one in the genus with striae on the anterior portion of the propodeum. Besides that, it is characterized by the frons with denser punctation between compound eye and frontal line (Figure 4B), interspaces about as long as puncture diameter; absence of long erect setae ventrad ocellar triangle level (Figures 4A–C); antennal sockets separated by one socket diameter (Figure 4B; ventral margin of fore femur strongly curved and carinate (Figure 4E); and by the broadened marginal cell on forewing (Figure 5D). The diagnosis of O. huaoranii by Gonzalez & Roubik (2008) can be applied. Distribution. Eastern Ecuador. Examined material. ECUADOR. RPSP: 2♀ “ECUADOR: Napo Prov. \ Yasuni Nat. Park. Est.\La Catolica T4- 26 Apr.\1998 Droubik No. 50” [Paratypes].