Common name(s): The Chinese name translates to "collared carpenter bee" based on its appearance and the misidentification as Xylocopa collaris.
A large bee, though one of the smaller members of the genus, reaching slightly more than 20mm. Female is mainly black. A thin ring of whitish yellow around the outer edges of the thorax, giving a "collared" appearance. Male is light yellowish overall.
This species has been misidentified in Hong Kong and mainland China in the past as Xylocopa collaris. This Asian species was described and named by Lepeletier in 1841, but this name turned out to be a junior synonym of the African Xylocopa collaris described by Olivier in 1789 and thus can't be applied to the Asian species.
This species is quite widely distributed through Hong Kong, Taiwan and Mainland China as well as much of Southeast Asia; there are probably several colour forms or subspecies. The one shown here is the one found in Hong Kong. A single specimen in the Raffles Museum of Biodiversity Research, National University of Singapore (soon to be renamed the Lee Kong Chian Natural History Museum) was apparently collected from Singapore long ago (will fill in the details when I process my data from my past visits to the museum), but I have never seen it in Singapore myself.
This is a fairly common species in Hong Kong during the hot summer months. It frequently appears in urban parks, and can be seen feeding from flowers in sunny weather. The nest is usually in a fallen log in forest; I have never seen it nest near urban areas. The male looks quite different from the female. I will add a photo of one later if I manage to take one in the coming spring and summer. The male, like many other carpenter bees, stakes out a small tree or shrub as his territory, alternately perching on a vantage point and driving off other males or any other flying insect, or hovering and flying slowly, patrolling in a most alert manner.