At Parke yesterday I managed to photograph a fly and a beetle which have life styles where their larvae predate the larvae of solitary bees.
The adult bee flies are vegetarian but they lay their eggs immediately outside the burrows of solitary bees – these then hatch and crawl into the nest and feed on the bee’s larvae. See here more details.
Here is a close up – the triungulins are waiting for a solitary bee to visit the dandelion flower – a single triungulin will then attach to the bee’s leg and be transported back to its nest where it will then detach and feed on the larvae of the bee
This is what adult oil beetles look like when they emerge from the bee’s nest – these were both photographed last May again at Parke. The animal at the top of the picture is a female and the one at the bottom is the male.
Buglife in partnership with the National Trust is carrying out a survey into oil beetles – see here for details on how you can get involved.
Whilst the life styles / behaviours of bee flies and oil beetles might seem disturbing – remember that both bee flies and oil beetles are pretty rare whilst solitary bees are pretty common – if the balance were the other way around it just wouldn’t be sustainable!