Oh well. Thanks for the info. I wonder what brought them here, then. Don't think I've seen more than about one green one every 18 months or so, and we're not very spidery.

Your wasps will come back soon of their own accord. What a shame about the wasp traps! People, in their ignorance, fear predatory wasps needlessly.

Hi Soilsenasuil, Sound like you've got a Baldfaced Hornet in your garden. Do they look like this (see below)? I suggest you spray round the area with a 'natural' spray made of orange and/or tea tree oil and treat around the area the hornet is flying or where its taken up residence in the Carpenter Bee home. Have a look at this site that goes through options in more detail: Baldfaced Hornet sprays How that helps :)

Take a dead one to your local Agricultural Extension Agency. They can identify it for you. If you don't see them coming in from a vent, like a dryer vent,don't see them in the basement,etc. then they may be coming in from the ceiling fixtures which means they have a nest in the attic. It's so easy for wasps to get in and make nests with all the spaces that are open in today's aluminum/vinyl siding and soffet installations. You usually see them flying around in a certain area outside. You might have to call an exterminator if the nest is large. It is best approached at night when they are in the nest. Spraying such a thing in an enclosed area is going to be hard because they will be on you all of a sudden. You have to use a lot of judgement in dealing with an internal nest. If you can find the small crevices they are using to enter the attic, you can buy some stainless steel wool and plug thoses openings to keep future ones from doing it again. Sometimes you can best see these openings from inside the attic during the daytime,if the attic is dark enough. Shove steel wool in every opening you see. And also outside where the corner and J-channels meet the siding at the overhangs. Good luck.