They may if they choose to fly from flower to flower. They will not if they don't.

Dan

Not likely, wasps are primarily predators feeding on other insects. The nectar feeders are the pollinators.

Wasps in general can be pollinators if they search for food in flowers, as the pollen will stick to their bodies and get transferred.

If they do not search for food in yellow flowers that day they will not pollinate the butternut flower. I get plenty of wasps (albeit few yellowjackets) visit my yellow fls in the garden. Albeit just the other day I found a yellowjacket sleeping in a butternut flower, and yesterday morning when I uncovered my vine a yellowjacket flew out from under the cover.

And if it were me, I wouldn't count on it and I hand-pollinate butternut when possible.

As for knocking a wasp nest down, I have one about 9 inches from the pepper patch. They haven't bothered me one whit the entire season. Not a problem.

Dan

Thanks everybody. I appreciate all the responses. Maybe the wasps are why the caterpillars aren't eating my squash leaves anymore -- maybe the wasps are eating them! I don't have any desire to kill the bees. I'm hoping to just leave them alone and vice versa. Thanks again.

They produce fast and soon, so that wasp nest can be a network of nests before you know it. If they're eating your caterpillars good job and I hope you leave them be. I think they pollinate a lot because I've never seen them be predators, but have seen them lingering in the flowers of my plants just like a honey bee. I never noticed what color the flower would be, they don't seem to mind landing on the squash flowers, so I don't think the yellow rule is one to follow. They like all flowers in my yard at least.

I remember my uncle telling my red haired brother that wasps didn't sting red headed people, so at the age of about 4 or 5, when there was one crawling on the floor, he stomped on it barefoot, it stung the crap out of him. That's why your post about yellow flowers made me laugh. I think they land in all flowers.

They WILL patrol the garden for caterpillars to feed to their babies.

I don't know where their nests are, but I can usually see a dozen or so wasps inspecting the garden at any time. I have very few problems with caterpillars.

Some adult wasps eat pollen and nectar while they are foraging, but I don't think they are good pollinators.

In spring and early summer they pick caterpillars for their young, in late fall, they are all collecting as much nectar as they can get. They will swarm on cowpea nodes, on compost piles containing watermelon, fruit, anything sweet, in the fall.

You might want to make sure that your wasps are not yellow jackets, which hover from side to side as they land. Yellow jackets will become aggressive to protect the nest or even a food source. So if a little kid bumps a nest by mistake there could be disaster.

I had to burn out a yellow jacket nest this summer and then in fall the survivors swarmed a compost pile full of overripe melons and aggressively protected it. My neighbors have small children, so I sprayed the compost with Sevin and dusted it with borax. The survivors moved to swarming on the cowpeas, so I sprayed the cowpeas with Sevin and hung a soda bottle trap half full of watermelon juice with a dash of dishsoap on the trellis. When I took the vines down, the survivors moved back to the compost pile.

I'd almost rather have caterpillars. In fact I did have caterpillars, in the beans and in the peppers, never seen them in either plant before. I wonder what they were.