Bumblebee Aware July 2021 by Adrian Doble

  • It is a pleasure to see places locally where grass has been allowed to grow long on verges, and in Parks and gardens, and on other parcels of public land.  The wildflowers have been able to bloom in a way that we have not seen for a long time.  This is despite the powerful lobby that insists on public spaces looking “Tidy”. 

    When we are planning “Pollinator Places” or Wildflower Meadows, we need to allow for this and to include species like Wild daffodil, White dead nettle, Comfrey and Green alkanet that will provide interest when most wildflowers die down in the winter.  Also, the inclusion of evergreen species to provide structure, perhaps even in obvious patterns, would help to keep the public on side.

    The local lime trees are in flower and increased numbers of dead bees can be found below them.  This is probably because their nectar contains a toxin that is lethal for them.  Unfortunately, it also has a special attraction for bees.  (The powerful neonicotinoid insecticides have a similar attraction for pollinators.)

    One of the more noticeable bees that is on the wing now is the Tree bumblebee, Bombus hypnorum.  It has a ginger thorax, a black body, and a clean white tail.  Because it nests above ground in bird boxes and cavities in buildings, we are more likely to see it than other species that nest in holes in the ground.  The males have a habit of hanging around the nest entrance, waiting for the new queens to emerge, and people sometimes worry that they are seeing a swarm of honeybees.  The good news is that male bumblebees have no sting, and they give up loitering after a couple of weeks. 

    This species arrived in the UK in 2001 and has spread at a rate of 50 kilometres a year, from its first site in Hampshire to reach Scotland by 2013.  It has a short tongue and so feeds on shallow flowers like Hawthorn, Bramble, Rose and Cotoneaster, but usually feeds within 100 metres of the nest.  So far, the Tree bumblebee seems to have avoided the attention of cuckoo bees which are thought to occupy up to 50% of the nests of other bumblebee species, and to reduce the numbers of the host offspring, including the individuals that would ensure the future survival of the family.

    During the autumn, the most important flowers for bees include Snapdragon, Catmint, Echium and Marjoram.  As many young, mated queens will be preparing for hibernation, they will need loads of pollen and nectar in order to build up the fat reserves that will keep them alive through the winter.

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