Large paper wasp nest in shed seems to be impenetrable to sprays

Asked October 6, 2019, 12:13 PM EDT

Over the years I have dealt with and eliminated many paper wasp nests, both large and small, in my sheds. I'm referring to the large umbrella-type covered nests, which are coated by whatever the wasps use to somewhat waterproof the nest, which protects the cells. I have always been able to eliminate these nests, some of them quite large, by spraying one or two cans, completely saturating the nest, with Wasp/Hornet sprays of several different brands. One application after dark has always been enough. I was always able to remove the nest the following day, with no wasps buzzing around the nest. Until now, that is. This year I seem to have some super-paper wasps that have constructed a large,and apparently impenetrable nest in the corner near the ceiling of my shed, which has resisted five cans, over three nights, of complete saturation. The spray seems to just coat the outside of the nest and flow down into the floor of my shed without having any effect on the interior of the nest. This has also been the first time I've seen wasps buzzing around the nest, in pitch dark, after saturating it. I don't know what to do. What I do know is I do not want to spend $200 for an exterminator. What can I do that does not involve risking who knows how many stings by knocking the nest down into a a cloth bag or into hot water, etc.? Thanks in advance for any help.

Michigan insect issues

5 Responses

The most important detail in using the sprays is to direct the pesticide at, or preferably inside, the main entrance/exit hole, which is usually at the bottom of the nest structure. This can be difficult in a tight place, like a shed. It is rather odd to see wasp activity at night, adding to the degree of difficulty. What you need now is a very cold night to help with the pesticide attack. I would not try any other method of destroying the nest, it can be pretty dangerous.

After researching this type of problem pretty extensively online, other experts suggested using a dusting powder, which I did, and which worked even better than I expected.

I see that I can post only three images, so that is what I have done. I have several more photos, that would help explain my method, but I guess I won't be able to add those. The photo of the nest itself is post-eradication, and is significantly smaller than it was when it was healthy.

The wasps’ doorway seemed to be in a tiny hole in a top outside corner of my shed, which is about eight feet above ground. Try as I might, I could not find a doorway on the nest itself.

My objective was to completely coat the nest with the powder, and of course to also get some poison into the hole outside. Both tasks proved quite difficult.

I could not find a bulb duster longer than one foot, which was not enough, for several reasons. The dusting powder came in a soft plastic tube, sort of like restaurant ketchup bottles, which couldn’t shoot the power out more than a few inches.

I didn’t want to get that close to the nest, and of course this wouldn’t do for the hole outside. I wanted to be able to run away if the wasps attacked me, so I wanted a looong pole of some kind. I was concerned about this because even in the dead of night, in total darkness, there will still a few buzzing around the nest, which I realize is odd.

Anyway, I invented my very own blowgun. I bought some plastic tubing, cut about a six foot off, and because the tubing is stiff, taped it to a stout length of bamboo.

The following may sound bizarre, but the only way I could get the powder up to the outside hole was to bury the end of the blowgun inside the dusting powder bottle, take a deep breath before putting my mouth on the other end, extending the weapon up to the hole, and blowing as hard as I could. I did this several times, but the amount that actually got into the hole which must have been their doorway could not have been more than a couple of tablespoons...and perhaps not even that much.

The blowgun would not work for the nest, because I had to get a lot of the poison on the nest. So I had to resort to removing the top of the dusting powder bottle and just flinging it at the nest, which was a very messy process, believe me. The stuff seems to stick to whatever it reaches, so I was able to get quite a bit of it on the nest.

Based on what I’d read elsewhere online, the powder is supposed to take several days to accomplish its task. But I went back about 30 hours later, in broad daylight, and the wasps were either all dead or had exited the building as they say. Or it could have been a combination. I saw four of them barely crawling on the floor of the shed, and a single wasp that entered the outside hole, never to appear again, while I was there.

And that was that.

I did not suggest the blown-in dust approach, because as far as I know, it is considered to be an illegal use of an insecticide by persons that are not certified pesticide applicators in the state of Michigan. The legality of using the product in this manner would ultimately depend on the "directions for use" part of the label. Different brand name products with the same active ingredient may have different restrictions on application methods.

I am happy that your efforts seem to have worked.

The dusting powder I used contains Permethrine. I looked it up on the Internet, and apparently it's also used to treat head lice and other bugs on the human body. It's available everywhere, including Amazon. It's supposed to be safe for humans, but apparently not particularly safe for pets, and perhaps not for pregnant women. It's described as lethal to most all bugs, crawling and flying. I couldn't find any information stating it's illegal in any state, or limiting its use to certain individuals.

All I know about Permethrine is what I read online; where I found many discussions of the product. Perhaps Michigan is different. I just don't know. Anyway, it solved my problem completely. I still do not understand why the spray approach did not work on this nest, especially since I sprayed it three times.