There can only be one candidate this month – Bombus terrestris – the Buff-tailed Bumblebee. Throughout the summer this is the commonest of our bumblebees, but in January, it is the only one! Bumblebee colonies die off in the Autumn leaving only newly-mated queens to survive the winter by hibernating underground. These bees depend on their existing fat reserves to survive until Spring. However since the 1990s, this species has managed to start a winter generation. On warm days, workers can be seen seaching for essential nectar and pollen, relying on introduced winter-flowering species (such as Mahonia and Hebe) in parks and gardens in urban locations.
Queens can also occasionally be on the wing on mild, sunny days. Many will carrying mites on their thoraxes like the one below. Mites live in bumblebee nests as scavengers on wax, pollen and nest debris. When the nest dies out in Autumn, the mites hitch a lift on a young queen, and will set up home in the queen’s new nest in the following Spring. They are thought to be harmless to the bee.
So watch out for Buff-tails in your garden this month, and check out our previous blog: https://thepollinatorproject.wordpress.com/2017/11/08/get-planting-now-to-help-early-spring-insects/ on winter flowering plants to help these hungry bees.