Thread subject: Diptera.info :: Volucella larva attacking living adult wasp

Posted by Thomas M on 11-08-2015 00:29
#1

Hello all,

I'm new here in this forum - so please have a bit of patience with me at the beginning... ;)

I have posted this request in another forum, and the advice was to post it here as well to get some more experts' opinion.

Some days ago (1st August, to be exact) a friend of mine and me discovered a wasps' nest in a hole in the ground ~20 cm deep (maybe dug some time before by a dog). Location: at the edge of a forest in western Taunus region near Limburg, Hesse, Germany.
In the upper part of the hole, an adult wasp was fighting against the larva of a species unknown to me - and the wasp obviously lost the fight. The larva was wrapped around the wasp's thorax (probably the most effective way to get out of reach of the wasp's sting) and seemed to kind of strangle it - see pictures below. At least at the beginning, the wasp was still alive and tried to defend itself.
Now in the other forum I've been told the larva was one of Volucella, maybe Volucella pellucens.
As it seems, it's not new that Volucella larvae are living in wasps' nests, feeding on detritus, dead wasps, and also on the wasps' larvae from time to time.
Hence my questions:
1. Can the Volucella larva on the pictures be determined more exactly?
2. How comes the Volucella larvae are not killed by the wasps? In the end, they are parasitizing their offspring...
3. Is it a known behaviour of Volucella larvae that they are (sucessfully) attacking adult, living wasps? I did not find a hint for that in the internet...

Thanks a million in advance.
Best regards,
Thomas

Posted by Thomas M on 11-08-2015 00:30
#2

...2nd picture...

Posted by Thomas M on 11-08-2015 00:30
#3

...3rd picture...

Posted by Thomas M on 11-08-2015 00:31
#4

...4th and last picture...