Otis, G. W. | bioRxiv Science

bioRxiv2024

The distribution of Apis laboriosa revisited: range extensions and biogeographic affinities

Apis laboriosa, the Himalayan giant honeybee, inhabits the foothills of the Himalaya and neighboring mountainous regions. Here we revise its distribution in light of recent reports and discoveries. The range now extends from longitude 105.9{degrees}E in Cao Bang, Vietnam, in the east to 74.4{degrees}E in the Pir Panjal Range of western Himalaya, a linear distance of 3300 km, with the most notable new localities in northeastern Vietnam, central Myanmar, northern Thailand, and AJK-Pakistan. The species generally occurs at lower elevations in the eastern part of its range than in Nepal, northern India, and the border region between India and Pakistan. Most but not all of the new localities are within the range predicted by species distribution modelling. We discuss the new localities that fall outside of the predicted range, the biotic characteristics of the terrestrial ecoregions in which the species occurs, and the remaining regions that may harbor this spectacular honey bee species.

ecology↗

bioRxiv2024

Taxonomic Revision and Identification Keys for the Giant Honey Bees

The taxonomy and phylogeny of the giant honey bees (Apis; subgenus Megapis) are still controversial and unresolved. The species boundaries within the subgenus are unclear and some species that are recognized on the basis of genetic differences lack supporting morphological characters. Two species are now well accepted: Apis dorsata F. of tropical regions of Asia and Apis laboriosa Smith that inhabits the foothills of Himalaya and neighboring mountain ranges. In addition, researchers have suggested that the two allopatric populations of giant honey bees that inhabit Sulawesi, Indonesia (A. binghami Cockerell) and the oceanic Philippine islands (A. breviligula Maa) as well as the South Indian form also deserve species status. We conducted a taxonomic study based on morphological characters of Megapis from throughout Asia. Our study confirms that Apis laboriosa is a distinct species based on numerous morphological characters. Moreover, A. dorsata of mainland Asia differs from the two island taxa based on coloration, ocellus size, and the spacing of compound eyes and ocelli. We found no evidence that breviligula of the Philippines has a distinctively short tongue, and report only one minor character (the shape of sternum 5) that differed statistically between bees from Sulawesi and the Philippines. We conclude that the bees from these islands represent a single morphological species, A. binghami, with two subspecies, A. b. binghami and A. b. breviligula. Apis dorsata from the Andaman Islands are smaller than but conspecific with those of mainland Asia. We found no morphological autapomorphies in the giant honey bees of southern India known to differ in mtDNA from A. dorsata from elsewhere in mainland Asia. We provide a taxonomic keys to workers and drones within the subgenus Megapis.

zoology↗