Paul Sweet replied: Hi Barbara, i cannott advise you any further than i already have. Short of coming out to have a look myself, the only suggestion is to call someone out who is local to you who knows what they are talking about.

You should be able to find someone close to where you live on my other site, the link is in my previous answer.
Regards
Paul
This reply was made on 2010-07-14

Paul Sweet replied: Hi Clive, 20-30 is a sufficiently high number to indicate that there is a wasp nest close, perhaps you just haven’t found it yet?

If they are getting into the conservatory, they will kill themselves against the glass trying to get out, or if they are trapped in there for any length of time, they will dehydrate or starve to death.
I would suggest you have a closer look around the vicinity of the conservatory and see if you can find where a nest is, or the entrance to the nest. You will see wasps arriving and leaving from the same place.
Regards
Paul.
This reply was made on 2010-07-11

Paul Sweet replied: Hi Paula, the wasps still inside the nest will find another way out, and the wasps oustside will find a way in.
Where this happens is anyones guess.
Regards.
Paul
This reply was made on 2010-07-10