The Bilberry Bumblebee

Queen of the Mountain

The Bilberry, or Mountain, Bumblebee, Bombus monticola, (bombus meaning ‘bee’, and monticola meaning ‘mountain’) is a relatively small, but gorgeous looking bumblebee with a distinctive orange/red behind making up two-thirds of its abdomen and two lemon yellow stripes on its thorax, or middle parts. The queens, workers and males all have the same markings but the male has short yellow bristles all over his face.

It’s quite often one of the first bees to be seen on the moors as the Queen Bilberry Bumblebee Awakes from hibernation around late March to early April to start looking for a suitable nesting site. This will usually be a patch of bare ground under dry vegetation and once this is located she will gather soft, dry, materials such as grass and moss into a ball and use them to insulate her nest.

The Queen’s Chambers

The queen makes a chamber inside this nest with a single entrance and secretes wax from her abdomen and forms it into a pot, then she fills this with nectar that she’s gathered from any early flowering Bilberry or Clover she can find. Next to this she will deposit a wax covered lump of pollen inside which she will lay around a dozen eggs.

The queen then incubates her eggs until after a few days they hatch, then the larvae begin to feed on the pollen which the queen must continue to replace as they grow. After a couple of weeks the larvae will spin a cocoon and then pupate for two more weeks until hatching. Some of these bees will stay at the nest to help rear the next brood of workers but most will venture forth from the nest and begin to forage on any flowers they can find for pollen and nectar to bring back for the nest workers and developing larvae.

Preparing for winter slumber

This breeding cycle then continues until around June when the queen will switch from producing workers to producing males and new queens instead. These can be seen emerging from the nest around August. These young queens have to concentrate on building up fat reserves for winter so will spend all their time foraging for food, but they also have to search for a mate and then try to find a suitable hibernation spot where they can overwinter, living off the fat reserves they built up, whilst the rest of the colony dies off.

The Queen’s future

As the Bilberry Bumblebee thrives in colder areas of the country such as the northern uplands, and is dependent on well managed heather moorlands where there is an abundance of Bilberry and heather, it is therefore very vulnerable to climate change and loss of habitat. Fortunately though its numbers seem to have recovered recently and as so much attention and work is being put into maintaining and restoring the moors here its future looks promising.

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