Apis laboriosa

In a 1980 morphological study, Apis laboriosa was judged a distinct species and considered the largest honey bee in the world.

Workers measured in that study averaged about 17.50 mm in body length, compared with 16.47 mm for workers of Apis dorsata.

The top of its abdomen is uniformly blackish, whereas the lowland giant honey bee Apis dorsata has pale orange-brown basal segments.

Mapped records come from seven countries: Bhutan, China, India, Laos, Myanmar, Nepal and Vietnam, with Nepal and India holding the most localities.

Known localities range from about 230 m to 4270 m above sea level, and 77.2 percent of records lie between 1000 and 3000 m.

In northeastern India colonies occur in summer at sites as low as 850 m above sea level.

It has been suggested that the timing of drone flight may keep Apis laboriosa and the closely related Apis dorsata from interbreeding, but more data are needed.

It is a spectacular but poorly understood species, largely because it usually nests on inaccessible cliff faces in the Himalaya.

Nests are single combs built in the open: two nests recorded in Nepal were each about 1 m long and built side by side under a cliff about 10 m high.

Colonies abandon most nesting cliffs in autumn and spend the winter as swarms without comb at lower elevations.

In Nepal, drones were seen flying in the early afternoon, between 12.20 and 14.20.

Honey-hunters tell the two giant honey bees apart from experience: the cliff bee with a black abdomen and the tree bee with an orange abdomen.

The first specimen was collected in the mountains of western Yunnan and named by Frederick Smith in 1871, but the species was long ignored; some later authors treated it as a subspecies of Apis dorsata.

Asian honey bees, and especially species like this one with a restricted range in hard-to-reach areas, remain dramatically understudied; no formal conservation assessment was found.