Bombus leucomelas, n. sp.— ♀. Black, with deep black pubescence, except that on anterior half of mesothorax, which is grayish, tipped with black, and on abdominal segments 3–6, which is pure white; clypeus arched, weakly and very sparsely punctured; labrum basally with two widely separated tubercles; joint 1 of flagellum equal to 2 and 3 together; wings deeply infuscated, iridescent; basal joint of hind tarsi not pointed at apex; pubescence of legs black. Length 21–22 mm.