Yes, this is a bumble bee.
Rarely found at such low altitudes, this one was found at the top of Kadoorie Farm.
This is Bombus eximius, a species of bumblebee that belongs to the subgenus Melanobombus in the simplified subgeneric classification.
Simply put, Bombus eximius is a very large species of bumblebee, and this one is so large as to probably be a queen
