Hornets or wasps

[Alves]

Yesterday I was cutting the grass on the embankment in front of the house. This slopes down to a retaining wall and the coping stones are level with the grass. One stone has a bit broken off on the grass side and this was sticking up a bit. I tried to kick it down into place and then tried to remove some soil that was preventing it going back. At that point I got stung on the wrist. Several times. And a load of striped insects followed me up the path and into the house. Fortunately most of them followed me back out again and I killed the rest by swatting them. My wife was most sympathetic, and apologised that she could not turn on the video function on her phone to capture my rapid return to the house. I dusted the area with wasp killer powder and (and myself with TCP) but it was some time before I could recover the mower. I eventually did so by pulling it with the cable and when it was moved away from the area, the cloud of insects lost interest.

Today, they are still there, crawling and flying out from the place where the stone is broken. I have squirted in some more powder. The wall is of random stone, except for the large curved copings, and is "semi" dry construction, i.e. there are a lot of dry joints and some mortar joints. Are these things hornets or wasps? And how do I get rid of them, preferrably permanently. They look more brightly striped than other insects that we have in the lawn. These ones seem to live in small holes in the turf and hover close to the ground and have caused no problems. So far!

[paulsherwin]

Some wasp species do build nests underground or in walls. You may need to get a professional in to get rid of them, since it can be dangerous to try to destroy the nest yourself if you don't know exactly what you're doing (the wasps can swarm out and attack, stinging hundreds of times.)

This Wikipedia article may help you identify the insects.

Paul

[Alves]

You are not joking about the swarming out and stinging bit! I have experienced this before when I was trimming a fuchsia bush with the hedge trimmer and found a wasps nest.

At least with that lot I managed to treat them with wasp-killing powder. This lot seem immune to it. They are still flying in and out after two days and two treatments.

I would have thought that the powder had maybe lost its potence except that on Friday my wife disturbed another nest in the shed when she removed a cooking pot that was stored there. The nest had been built from the rafter and onto the surface of the lid. She was lucky not to get stung. There were a few wasps present, so I dusted it and left it overnight. Next day they were all gone (or at least not to be seen) and I removed and burned the nest.

I think I will just leave the nest in the wall untill autumn or ask the local stone mason what he does when he meets this problem. I suspect his solution will involve the use of red diesel, which he seems to use for a lot of horticultural problems!

[timbrenn]

It could be dangerous for you to try it yourself with out the right protective clothing. I would recommend you leave this to the professionals.