Wasps in ground.

[Billyfozz]

yeah no problem mate... And you're right they're really fast.

[kercock]

I virtually just joined and wanted to ask the same question ! Firstly, Hello, I live in Perthshire,Scotland and was out walking with Joe,my dog ,when I first saw the wee volcanos ,not having seen them before I was puzzled to say the least also there was no activity around the area to give a clue as to what had made the sandy piles with a hole on the top. We went to the same area next day,almost all was revealed ! There were some insects around which to me looked like a cross between a wasp and a flying ant (the best description I can think of ) Some arived carrying a fly, similar to a house fly, it would land near a "volcano" and reverse down the hole dragging the fly with it.
I noticed yesterday that there were a few much bigger wasps around doing nothing consructive, they certainl seemed to be the same species but larger.
There had been some heavy rain during the night before last and it was noticeable the the rain had collapsed the tunnel entrance on the top of the "volcanos" and the wasps had tunneled throgh the side of the "volcano.
I will go back there later today to see if there are any changes...............................kercock

[eucera]

Now these certainly sound like Mellinus arvensis to me. Your description of the behaviour is just as I would expect for this species.

[kercock]

Having been back to the wasp site I noticed there were several dead wasps around,Could it be that because of the colder weather beginning to arrive the nest site is starting to die off ?
I also notice that although the "volcanos " are certainly concentrated in an area about 10m by 2m some are as much as 50m away from the main area. I assume this is fairly normal.
Are these wasps fairly rare ?Never having seen them before,having spent most of my 68 years in the Perthshire countryside,thinking I am quite observant and yet no previous sighting of the fascinating creatures and their "volcanos".

[JRsbugs]

I don't think Mellinus arvensis would be dying off yet, mine haven't been around for long enough yet and I doubt the weather has been cold enough to kill them.

I have nest holes everywhere in a certain area, they prefer one bed where I have Campanula species dying off, I guess the roots keep the ground loose and provide some shelter but not too much. They certainly are on the increase in my garden, but I only noticed them maybe 3 to 4 years ago.

They do now make holes a little further afield in the edges of adjacent beds, usually near the grass edge which has overhanging grass. The grass is quite poor but it grows well at the edges of beds, I'm not cutting it to preserve the wasps nests and also the wildflowers which are springing up all around. I imagine they would nest anywhere suitable, and if numbers are high the would spread their territory or have their own territory and spreading their bets so to speak would improve chances of survival.

I wonder if there has been males killing each other, I don't know if they do that but I saw two males having territorial battles a few days before I saw a mating couple which also had an extra male hanging onto the female's back! I got a few pics too.

Mine are extremely busy taking flies down their nests, I saw 3 in fairly quick succession a couple of days ago being stuck through the tongue by the female then dragged down a hole. By the time I found the holes the wasp had already disappeared but this morning I have seen one land, looking as though it couldn't find the entrance but then stuck it's tail down and reversed with it's fly. That was a smaller fly which could have been an Anthomyiidae, the others were Pollenia and a Calliphora vicina which the female had and she is big, well over 15mm long! I would say she has to be closer on 20mm when stretched. The one I saw this morning was smaller so I thought it was a male, I guess they catch flies too but I'm not sure and if they do it would require a female to lay the egg afterwards, or maybe it's extra provisions. The markings are different on the males but I didn't have my camera so couldn't see it well enough.

I have very few flies around so they are doing a great job!

[kercock]

many thanks for the fast reply,much appreciated. I am just this minute back from the wood where the wasps are and my theory of the wasps dying off went right out the window.The first thing I noticed was fresh earth and there were two of them digging away ! Of course there were no dead wasps lying around either !!
Today there is a strong north wind blowing so it is quite a bit cooler than usual but there was a fair amount of activity,the meals on wings arriving regularly.
I did manage to take some photographs so the hunt is about to begin for the cable to connect up to the computer so I can hopefully get them in the Gallery ! ............................kercock14

[kercock]

On this very wet and windy morning I had a walk out by the woods ,into the area where I had first seen the wasps.
It was like they had never been.! No "mini molehills" no "volcanos" either.
It looks very much like it's all over for the year. Two mornings of hard frost and some very wet days seem to have finished off the wasps.
I will of course be on the lookout for them next year. It has been an interesting few weeks with the wasps and thank you one and all for your help Dennis.