A medium-sized to large hornet. The specimens from Chiang Mai in my collection average 30mm and are mainly brown, with a lighter yellowish head. My single Russian specimen is light brown with faint yellow stripes on the abdomen, and only around 22mm. The key distinguishing feature of Vespa binghami are the ocelli, which are a group of three tiny simple eyes arranged in triangular order on the forehead, between the compound eyes. The ocelli on this species are much larger than those of any other species in the group.
This species can be found in Northern Thailand (Chiang Mai), Myanmar, Laos, parts of India, parts of China (Yunnan, Sichuan), Korea and parts of Russia (Primor'ye, Sakhalin).
Above: One of my most precious specimens, the only Russian Vespa binghami.
Below: Closeup of head. Again, note the enlarged ocelli.
Very little has been written on this species. It is apparently quite rare throughout most of its range, and is unusual in that it is a nocturnal species! This is probably the main reason behind the enlarged ocelli.
I have three specimens from Chiang Mai, Thailand which are of the typical colour form, plain brown with a lighter head. All are large, averaging above 30mm in length. The specimen from Russia, however, is only 22mm in length, and is of the colour form/subspecies Vespa binghami suprunenkoi. I am not sure if most Russian individuals are so small or if the only one I have is an unusually small worker.