Interesting Behaviour of Solitary Wasp, Cerceris arenaria
For several years a colony of the attractive solitary wasp Cerceris arenaria has occupied nests between the old paving slabs at the back of my house in Astley Burf. Like all species of solitary wasp they provision their burrow with a particular type of prey and in the case of C. arvensis this is always weevils. The paralysed prey is carried in flight below the body of the wasp and is never released prior to being dragged down into the nest burrow. If the wasp has to relinquish hold on the prey even for a very short time it is discarded, thus avoiding the possibility that it has, in the meantime, been parasitized.
On 21st July 2012 I noticed one of the wasps arrive at its nest carrying a large Vine Weevil, which it tried for some time to pull into the nest hole but this was far too small to accommodate such a large prey. After a struggle it gave up the attempt and ejected the hapless, paralysed creature which just lay inert near the nest entrance. The wasp then emerged and immediately began furiously to dig out the burrow, presumably to accept larger prey. In so doing, it ejected a further three or four smaller weevils with which it had previously provisioned its nest. All of the prey was just abandoned around the entrance and no attempt was made to carry them back into the enlarged nest. The burrow continued to be used, presumably by the same individual (Figs. 1-4.)..
This action seemed to be an exaggerated response by this particular wasp as on previous observations prey that is too large would be discarded but no further steps taken to enlarge the burrow. Some ‘tidying up’ does occur from time to time following disturbance of the soil cone around the nest, but this is usually restricted to a small amount of clearance of the entrance to the burrow and the re-establishment of the neat cone around the top.
Fig. 1. Cerceris arenaria attempting to pull Vine Weevil into nest. Jane Scott
Fig. 2. Cerceris arenaria and discarded weevils. Jane Scott
Fig. 3. Cerceris arenaria digging and discarded weevils. Jane Scott
Fig. 4. Cerceris arenaria digging and discarded weevils. Jane Scott