Tree Bumble Bee

Bombus hypnorum has a short proboscis and a rounded head. The thorax is usually of a uniformly ginger color (but examples with a darker, or even black thorax occur), the abdomen is covered in black hair, and the tail is always white. In workers, the first tergite (abdominal segment) is black-haired, but a proportion of males may have ginger hairs intermixed with the black hair, both on the face and on the first abdominal tergum. On the European continent, individuals with extended yellow coloration exist. Workers are often (but not always) small, while drones are much bigger in comparison. The queens vary in size.

B. hypnorum is a common bumblebee species in continental Europe and northern Asia, from northern France to Kamchatka in the east, and from the Pyrenees to the mountains in northern Europe. In the Balkans it is found in northwestern Greece. It is not found, though, in the Mediterranean, or the steppes of eastern Europe, only in the mountains of the Iberian Peninsula and not south of Tuscany in Italy. The bumblebee was first observed in United Kingdom on 17 July 2001 close to the village of Landford in Wiltshire and has since been spreading widely. In August 2008, B. hypnorum was found in Iceland, and new queens have been found each year since. It is likely that it will continue to stay in Iceland and prosper in close living with humans near dense settlements, such as Reykjavík, but will most probably not venture into the more rural and colder parts of Iceland. In the U.K., it has now spread from England up to the north of Scotland and Wales. It reached Ireland in 2017.

There are two parts to mating: approach and copulation. First there is the approach part where the male checks out the female. The male would approach a queen and then hover in the air for a few seconds using his antennae to inspect the female. If this male is the same species, then he will land and continue inspection using his antennae. The male mounts her by using his front legs on her abdomen and then mounts from the rear. Then he attempts to copulate with her. Females have a mandibular gland that releases a pheromone that the males react to so that they will know of their receptiveness. Males use their legs to tap on the abdomen of the female for a few seconds in ten second intervals. Males of B. hypnorum copulate for about 20-40 min.