I've finally found a way to deal with the paper wasps that not only suck berries (blueberries and blackberries) dry but deter me from even wanting to pick in the first place. I decided to use pyrethrin spray to squirt them and presumably kill them as pyrethrins are supposed to be very safe on edibles. When I find the wasps on a berry, I give them a squirt and they fly off to land nearby on a leaf or stem and start rubbing themselves. None have stung me while spraying, (although I have been stung when near their nests at other times). I am wondering if that is enough to kill them even though it may take a while? I've seen some of them fall to the ground and die but on my deck they usually make their way between the boards so I'm not certain they go ahead and die - anyone know for sure?

Next spring I will be hoping to kill them the minute they arrive and keep them from becoming so numerous in the first place. I've tried taking out their nests but there are so many inaccessible spots that I can't even make a dent. I'd also like to get some pyrethrin/synergist (piperonyl butoxide) concentrate but the sites I've located it on say that pyrethrins are in short supply this year. I get something like Garden Safe brand (Fruit and Vegetable or Houseplant and Garden, 24 oz) which is somewhat expensive compared to concentrate ($7.99) but well worth it to actually be able to harvest my berries.

They used to be on the fruit all night, during rain and I even popped a blackberry in my mouth with an attached wasp after neglecting to inspect it, (didn't sting me, thank goodness). I now am able pick in the evening after spraying in the day, as I've read that pyrethrins are degraded by sunlight. I then rinse them and eat them the next morning. I find only the occasional wasp still out there for some reason - maybe the repellent properties in action? Interestingly, I've always wondered about fly spray for horses and why no one seemed concerned about the amount the human applying it comes in contact with - turns out it's the same stuff, available in concentrate but I think it contains undesirable inert ingredients that make it undesirable for edibles.

Thought I'd pass this on as I have searched extensively on Garden Web and could never find a method to effectively deal with this problem!

Leslie