Key to both sexes of the species of Brachymelecta 1. Mandible bidentate, with inner preapical tooth as well as usual apical tooth (rutellum) (Fig. 14A). Mesoscutum covered in dense, uniformly golden-yellow hairs (Fig. 15). Mesoscutellum without pair of spines or well-defined mammiform tubercles, although mesoscutellum bigibbous to some degree and sometimes with pair of very minute protrusions (Fig. 15D). Mesotibia with black hairs only (Fig. 15A, C). T1–T4 without fasciae or with only very faint apical bands of golden-yellow hairs (Fig. 15B) ...................................................................................... B. larreae (Cockerell, 1900) – Mandible tridentate, with inner basal tooth as well as inner preapical tooth and usual apical tooth (rutellum) (Fig. 14B). Mesoscutum with pair of spots or bands (Figs 3B, 5B, 10B, 11, 13B, 16B). Mesoscutellum with pair of spines or mammiform tubercles (least developed pair shown in Fig. 13D) (see also Figs 3D, 5D, 10D, 16D). Mesotibia dorsally with some off-white or yellow-orange hairs, those of female sparser and usually reduced to small bands or spots (Figs 3A–B, 5A, 10A–B, 11, 16A–B); those of male forming patch of very dense off-white, golden-yellow, or yellow-orange hairs, occupying nearly entire dorsal surface (Figs 3C, 5C, 7A, C, 8A–B, 13C, 16C). T1–T3 with well-defined off-white to golden-yellow or yellow-orange apical fasciae (Figs 3A–C, 5A–C, 8A–C, 10A–C, 11, 13A–C, 16A–C), rarely entirely covered in pale tomentum (Figs 7A–C, 8D) ............. 2 2. Mesoscutum with pair of anterior spots or bands of hairs darker than surrounding off-white or yellow-orange hairs (Figs 5B, 13B). Mesoscutellum with pair of short, mammiform tubercles (Figs 5D, 13D). Maxillary palpus with four or five palpomeres (Fig. 12A) [North America] .................. 3 – Mesoscutum with pair of central spots of off-white or pale to golden-yellow hairs lighter than surrounding black hairs (Figs 3B, 10B, 11, 16B). Mesoscutellum with pair of spines (Figs 3D, 10D, 16D). Maxillary palpus with fewer than four palpomeres (Fig. 12B) [Greater Antilles] ................. 4 3. T3 and T4 each with fascia narrowed or interrupted laterally, mesad the inner pair of anterolateral extensions (Fig. 5A–C). Fore wing infuscate apically, subhyaline in most cells and around third submarginal crossvein and second recurrent vein (Fig. 5A–C). Head, mesosoma, and metasoma with pale hairs off-white (rarely pale yellow and never orange) (Figs 5A–C, 8) ........................................................................................................ B. californica (Cresson, 1878) – T3 and T4 each with fascia broadened anterolaterally, that of T3 into inner pair of anterolateral extensions (Fig. 13A–C). Fore wing infuscate throughout except subhyaline around third submarginal crossvein and second recurrent vein (Fig. 13A–C). Head, mesosoma, and metasoma with pale hairs typically pale yellow to yellow orange (Fig. 13A–C) ......................... B. interrupta (Cresson, 1872) 4. Mesoscutum with band of pale hairs along midline not attaining posterior margin (Fig. 3B, D). Mesoscutellum, except for pair of spines and around their bases, densely covered in pale pubescence greatly obscuring underlying integument (Fig. 3D) [Cuba] .................... B. alayoi (Michener, 1988) – Mesoscutum and mesoscutellum each with uninterrupted band of pale hairs along entire midline (Figs 10B, D, 11, 16B, D). Mesoscutellum pubescence otherwise dark brown or black, sparse, not obscuring underlying integument (Figs 10D, 16D) [other regions] ................................................. 5 5. T1–T3 with fasciae pale yellow, narrowly interrupted medially in female (Fig. 10B), complete in male (Fig. 9A) [Hispaniola] ................................................................ B. haitensis (Michener, 1948) – T1–T3 with fasciae off-white, widely interrupted medially in female (Fig. 16B), narrowly interrupted medially in male (Fig. 9B) [Puerto Rico and U.S. Virgin Islands] ......... B. tibialis (Fabricius, 1793)

Published as part of Onuferko, Thomas M., Packer, Laurence & Genaro, Julio A., 2021, Brachymelecta Linsley, 1939, previously the rarest North American bee genus, was described from an aberrant specimen and is the senior synonym for Xeromelecta Linsley, 1939, pp. 1-51 in European Journal of Taxonomy 754 on page 41, DOI: 10.5852/ejt.2021.754.1393, http://zenodo.org/record/4965956