Honey bees in the subgenus Megapis are the largest of all the species of Apis (around 15 mm or more in length and a forewing length of 12–15mm) and constitute a clade that is sister to A. (Apis).
Bees of the subgenus Megapis can be confused with other species of honey bees in the A. (Apis), but they can be easily distinguished by their large size, their fuscous forewings, and nests made of a single exposed comb.
As with all species of honey bees, bees in the subgenus Megapis are generalists and visit a broad range of plants for food.
Species of bees in the subgenus Megapis build their nests in the open as a single comb that overhangs from tree branches (Apis dorsata) or on overhanging cliff ledges of rocky mountainous areas (Apis laboriosa).
There are two species in this subgenus: Apis dorsata and Apis laboriosa (giant mountain honey bee). Some authors consider Apis dorsata as the only species in the subgenus, and Apis laboriosa as a subspecies of Apis dorsata. However, multiple other authors consider that Apis laboriosa is a separate species from Apis dorsata on grounds of molecular evidence (Arias and Sheppard 2005, Lo et al. 2010, Raffiudin and Crozier 2007), external coloration and morphology (Sakagami et al. 1980), reproductive isolation (Underwood 1990), and species of parasites associated with them (Anderson and Morgan 2007). Roubik, et al. (1985) also showed that Apis laboriosa and Apis dorsata nest, forage, and presumably mate in widely separated climatic zones.
Giant honey bees are found only in southern Asia. Apis dorsata is more broadly distributed than Apis laboriosa, which is thought to be restricted to the high mountains of the Himalayas. Trung, et al. (1996) reported A. laboriosa as present in the rocky mountainous areas of Sonla and Hoabinh provinces in northwestern Vietnam. The two species are rarely sympatric, with A. dorsata usually found below altitudes of 1500 m and A. laboriosa between 2500–4000 m (Roubik et al. 1985, Allen 1995, Otis 1996, Thapa et al. 2001, Radloff et al. 2011).