During the late autumn I spent several days watching common wasps Vespula vulgaris at their nests. Having a nest in the ground on my allotment was an excellent pest control measure. Despite large numbers of ‘cabbage white’ butterflies around the plot none of the cabbages were damaged as the caterpillars were quickly found and consumed by the wasps. The other nest was in the vertical bank by the River Dart on Dartmoor. Here I could sit fairly close without the wasps getting annoyed and watch them around the nest entrance. It was a large nest with about 100 wasps in and out every minute bringing in prey items such as flies and caterpillars. During November hundreds of new queens emerged from the nest. These could be recognised by their large hunched abdomens. They were also hesitant at the nest entrance as they emerged in to the light for the first time. Watch video here.
These new queens fly to nectar sources especially ivy where they are mated by the male wasps which swarm around the ivy in the autumn. The males can be recognised by their long curved antennae and slim bodies. They don’t have stings (only female bees and wasps have a sting) so it is possible to pick them up safely. The males die off in the autumn leaving the new queens to hibernate. They can sometimes be found in the winter under bark or in garden sheds. They will emerge in spring and start new nests.
Both nests died off by early December so I dug them up. One contained several bristly maggots. These are the larvae of one of the bee-mimic hoverflies of the genus Volucella. They live in social bee and wasp nests and these were devouring the remains of the dead wasps which remained in the nest.