Blue Mud Dauber Wasp

2009 March 14

When I was a kid, I used to find these blobs of mud stuck on our farm buildings, mostly under the eaves or in other spots where they would be protected from the rain. When I broke them open from time to time, they were either filled with paralyzed spiders, or had a wasp pupa inside. I’d often watch them being repaired and stocked by wasps that looked like this:

This is another old picture that I took in 2007, and the wasp was large enough that I tried getting the pictures without the macro lens, which is why the pictures came out a bit blurry.

[Note added in 2014: I’ve since taken some better pictures of blue mud dauber wasps, if you want to see the details better. They are here.]

I also refrigerated it, which made it pretty much act as if it were dead until it warmed up again. This seems to be a trait of hymenoptera – ants, bees, wasps, and sawflies don’t seem to take cold temperatures very well.

Anyway, it is a Blue Mud Dauber, genus Chalybion. The metallic blue color is quite striking, and the elongated, very thin waist is very distinctive.


While they are wasps, and they can sting, they are solitary wasps and don’t generally sting people except in extreme self-defense[1]. They mainly save the stinging for the spiders that they catch to feed to their grubs. What they do is this: first, they find, refurbish, or build out of mud a tube about one-quarter of an inch in diameter (roughly 5 mm). Then, they go and find spiders that they ambush, and quickly sting just so. They don’t kill the spider outright, because then it will start to rot right away. Instead, they just paralyze it, which keeps it fresh[5]. Depending on how big the spiders are, she’ll nab five or six of them and stuff them into the tube. Then she’ll lay an egg on them, cap the tube off with more mud, and start stocking the next tube. The egg then hatches, and the grub eats the paralyzed spiders as it grows. Then, come around fall, it pupates and waits for spring, at which time it finishes, pops out of the nest, and flies off to do in some more spiders. It’s a lot of work to build new nest tubes out of mud, so frequently they’ll just clean out an existing old nest and start over. They often take over the abandoned nests of other kinds of mud daubers (particularly nests of the related Black and Yellow Mud Dauber), or sometimes just take advantage of tubular openings that they find[2].

Whether these wasps are good or bad to have around kind of depends on your opinion of spiders. I’ve read that they will actually prey on black widows, if that’s the sort of thing that concerns you. Around here, though, the spiders they eat are really the sorts of things I’d rather keep around. Their mud nests are kind of ugly, too, and make things awkward when you need to repaint buildings.

I’m not quite sure why they specialize in spiders, it seems like it would be safer to go after things like caterpillars. The only reason I can think of, is that spiders are much less likely to have chemical defenses and toxins than caterpillars do[3]. It may also be that spiders are easier to paralyze for some reason, maybe it’s easier to hit their master nerve ganglion.

—————

[1] Most solitary wasps are pretty mellow that way, because there’s no percentage for them in stinging you unless you are actually killing them. See, if you have a whole nest of social wasps, then it is worth their while to sent a few out to discourage large mammals like us, because even if the defenders get swatted and killed, they are still likely to save the nest from being molested. The survivors can then continue taking care of the grubs, and the colony goes on. A solitary wasp doesn’t have that luxury, though. If she stings you to try to drive you away from the nest, and gets herself killed, then there’s nobody to stock the nest and the whole thing is a loss. It’s actually better for her to abandon a threatened nest and save herself, than to try to defend it. But, if you grab the wasp and try to kill her, she no longer has anything to lose, and that’s when she’ll sting you.

[2] My grandmother had these wind chimes that had kind of lost their chime, they just went “clunk, clunk” when the wind blew instead of ringing. I noticed that the weren’t working, looked into the tubes, and found that I couldn’t actually see through them. So, I took a piece of wire and rammed it through – and found out that the tubes were packed with mud. It seems they were just the right diameter to appeal to the mud daubers, and they’d used them for nests.

[3] Although, there’s one thing about spiders that live next to rivers and lakes. If the spider mainly eats insects that have aquatic larvae, those larvae are likely to have accumulated mercury from the water – particularly if they were predatory larvae preying on other, smaller animals. So, spiders in those conditions can have a very heavy mercury load[4]. This is evidently a problem for birds that eat spiders, because then they have an even larger mercury load, to the point where it can kill them.

[4] What happens with mercury is this: you start with a very tiny quantity in the atmosphere, that eventually gets caught in the rain and carried into rivers and lakes. The mercury then converts to a form that living things will take up. Plants grow, and some of this mercury gets into their tissues. An animal then eats the plants, and the mercury gets into their fat, which holds onto it. So, they end up retaining pretty much all the mercury that they eat, concentrating it to a higher level than it was at in the plants. Then something else eats the first animal, and concentrates the mercury still more. So, if you have a chain that goes something like algae => water flea => carnivorous caddisfly => bluegill => bass => you, there are four stages of mercury concentration before you get it. If we assume that each stage of concentration increases the mercury levels by a factor of ten, then you are looking at 10x10x10x10 = 10,000 times more mercury than if you had just eaten the algae. If, on the other hand, you have algae => carp => you, there’s only one stage of concentration, so you only get 10 times more mercury than the algae, which is much better. Basically, if you want to minimize mercury in your diet, you want to eat terrestrial plants, or animals that eat terrestrial plants, and you really want to avoid eating meat from carnivores that eat other carnivores that eat aquatic animals that eat aquatic plants. Eating meat from bears that have been eating salmon that have been eating other fish would be exactly the wrong thing to do.

[5] Which brings up one of my favorite entries in the Bulwer-Lytton Fiction Contest:

“Terry the Tarantula and Wendy the Wasp were frolicking and cavorting together in the Flowery Meadow, (as they were the best of friends in all the Enchanted Forest of Miggly-Wompsly) when, all of a sudden, and with no warning whatsoever, Wendy accidentally stabbed Terry with her stinger, making her very sad for she knew that soon her poison would paralyze her friend and after a while her eggs would hatch inside him, and then her happy wriggling larva would slowly eat him alive, but Terry tried to smile and would have told her not to be sad as this was how the Circle of Life was continued, but he was in too much pain and, as I mentioned before, paralyzed.”

(Delano Lopez, Washington, DC, in the “Children’s Story” category, 2001)

119 Responses
  1. Shawn permalink
    July 17, 2011

    We have these wasps in our backyard around our pool. They seem to really like the water…is this common or would that be a different kind of wasp?

    Thanks for the help and great website!

  2. Lindsey permalink
    July 17, 2011

    Blue Mud Dauber Wasp’s have been coming into my house. I don’t know how they are getting in. They have been spotted all downstairs. My husband has killed at least 6. I’m so scared of bee’s & spiders. Funny how this bee would help my one fear. Anyways I have 2 babies at home and I’m afraid that these bee’s will harm us. I looked outside and saw a lot of regular bee nest. But I didn’t spot any Mud Dauber nests. I did notice them going in and out of my attic vent. I’m guessing they are in there. My question is.. should I hire someone to kill them? I really don’t want them around.

  3. July 18, 2011

    Shawn: I’ve been noticing that, in our yard, the blue mud daubers are most attracted to just water (like moist grass, or the kids’ wading pool), while the black-and-yellow mud daubers are most attracted to the muddy area around the yard water hydrant. I think what’s going on is, the blue mud daubers are only reworking existing nests, and so they just need water to moisten things up. The black-and-yellows, on the other hand, are building nests from scratch and so need to actually have a source of mud, not just water.

    Lindsey: Yes, they are almost certainly in your attic. They like attics. Since the blue ones like to re-use old nests, the best bet for long-term removal will be to have somebody go into the attic around the end of August and remove all the mud nests they can find. That way, there won’t be any nests in the spring to attract them back. And then put some screen over the attic vent to keep the black-and-yellow mud daubers from building new nests that would, later, draw in more of the blues.

    I suppose the biggest danger to your babies would be that they might catch a wasp and try to eat it. I’d be more concerned about them eating a dead one (say, killed by poisoning), than a live one (which are pretty fast and hard to catch).

  4. July 18, 2011

    Kelly: I don’t think there is any way to keep mud daubers away from a decorative pond, at least not without doing something horrible like poisoning the water. They want water and mud, the pond has both, and that’s all there is to it as far as they are concerned. Maybe if you provided them with an easier source of mud in some inconspicuous place away from the pond, they would go there instead?

  5. Ashley permalink
    July 20, 2011

    In the cracks between our concrete slabs in our back yard next to our pool we have been finding holes in the dirt. I just saw an insect that looked just like this wasp but it walked as well. Do the mud wasp walk too? Also, do they make their nest in the floor by digging a hole?

  6. Lindsey permalink
    July 20, 2011

    We found more and more each and every day. I will have to call someone. I’m very scared. We live right next to a creek! So we have the perfect set up for them it sounds like. They are the blue ones for sure. Does this mean since they kill black widow spiders that we have BW spiaders? I live in the Finger Lakes NY.

  7. July 21, 2011

    Ashley: I’m not sure if the Blue Mud Daubers will nest in holes in the ground, but there are some similarly-colored wasps that will, such as “spider wasps”. They are a bit smaller, with a less elongated waist, and tend to build their nests underneath objects like rocks and flower pots. They are also solitary wasps (and so not inclined to sting unprovoked), and if you watch them for a while you’ll probably see them dragging some of their paralyzed prey into their holes.

    Lindsey: While they will kill black widows, they don’t have to. They will go after any sort of cobweb-weaver spider, of which there are many kinds. So no, the presence of the wasps does not mean that you have black widows.

    If you really feel that you have to do something about them, I’d suggest starting by watching them for a while to see where they are building their nests. Then, whatever you do can be targeted on that specific spot. Otherwise, if you call an exterminator they are likely to just generally hit your whole yard with insecticides, which I personally think is excessive and probably a waste of time and money. And, it is probably worse for you than having even a large number of mud dauber wasps around.

    If it were me, and I wanted to get rid of them, I’d locate the nests, wait another month until the adult wasps die off, and then just go in and remove all the nests by hand, no pesticides. They will be completely harmless at that point, and this will reduce the number of wasps that can come back to nest next year.

  8. Liz permalink
    July 27, 2011

    I have a million of these things in my back yard in my poplar tree, I have a pool in my yard as well, which I have had for 5 years now. These Blue Mud Wasps are new this year!!.. I need to get rid of them. I can not sit outside…I can not have people over as they are swarming every where.. I have tried raid.. but its useless…. I have set up the wasp cones to catch them…only the yellow jackets are going in there. We have climbed the tree to find the nest and can not locate it. What can I do to get rid of these?

    Ontario Canada!!

  9. July 28, 2011

    Liz: You aren’t going to find a single nest. If these are mud daubers, then each of these wasps has its own nest somewhere. The nests are probably under the eaves of buildings, or in the attic, or in crevices, or in a similar location that is protected from the rain. And if they are “spider wasps” (similarly-colored, but somewhat smaller), they are likely nesting under things resting on the ground. You aren’t going to find them in a tree. And they eat different things than yellow jackets do, so they aren’t going to be attracted to the wasp cones.

    The best thing is to watch carefully to find out where they are nesting, and try to close off the area or otherwise clear out the nests. I don’t think there is a lot else you can do about them that wouldn’t be worse than having the wasps around.

  10. Robert permalink
    August 6, 2011

    I was walking around the truck tonight and found about 10 blue daubers around it dead. These daubers are not at normal size, they’re about an inch and a quarter to a inch and a half. I have seen many but nothing as big as these blue daubers. I have pictures if you want to see them, I sized them up with a good size dragonfly and a dart.

  11. andrew johnson permalink
    August 11, 2011

    i got stung by one of these.. it landed on me without me knowing and i leaned onto my leg with my fist on it and got stung.. im not feeling very light headed.. and cant find a damn thing online about a sting.. anyone ???

  12. August 11, 2011

    Andrew: Well, given that you managed to get stung, I don’t think that the sting is likely to be much different from that of any other comparable-sized wasp. I’d expect some immediate pain, followed by redness, swelling, and itching that could last anywhere from a few minutes to a few days, depending on whether your immune system is sensitized to wasp venom or not.

    There is a small danger of anaphylactic shock from any insect sting, but that generally comes on pretty fast, so if you are still reading this and aren’t having trouble breathing, you should be OK. Light-headedness by itself could just be due to changes in your breathing as a response to the sting pain. If you actually had problems with passing out, difficulty breathing, or the other symptoms listed on this Wikipedia page, you should see a doctor to be tested whether you are in the tiny minority of the population who is in danger of life-threatening anaphylactic reactions.

    That should be about it. There may be specifically paralytic toxins in the venom, but they probably aren’t going to have that effect on you. Unless you are a spider.

  13. Jackie Hansen permalink
    August 25, 2011

    I have found by experience, unfortunately, that a paste of meat tenderizer/water applied immediately to a sting will reduce the swelling and pain. Refer to http://www.ehow.com/facts_5728870_meat-treatment-wasp-spider-bites.html for more info.

    We also contacted our physician and have an epi-pen (self-administered auto-injector of epinepherine) in the case of anaphylaxis. These generally need to be replaced on a yearly basis so check the expiration date. It may be overkill, but I don’t want to find out that one of us has a severe allergy and be empty handed.

  14. David permalink
    September 1, 2011

    I have these blue matallic wasps on my back porch. They look like they r conning from the ceiling of my porch. I am not exactly sure. But I have other wasp on my back porch that that are black and yellow. I have a son and my fiancee is currently pregnant. I live close to charlotte NC. What can I do about them? Can I get rid of them myself or do I have to call someone to do it.

  15. September 1, 2011

    David: The blue ones are almost certainly solitary wasps that aren’t going to bother anybody unless someone tries to hurt them. I’d ignore them.

    The black and yellow ones on your back porch, though, could be a different story. If there are a lot of the black and yellow ones coming and going from a hole in your porch, then you probably have a nest of yellowjackets or European paper wasps, and they are likely to sting without a lot of provocation. Whether you can clear them out yourself or not depends on how willing you are to take a chance on getting stung.

    Any of the standard “Wasp and Hornet Killer” sprays will probably work fine. What you can do to keep the stings to a minimum, is get one of those anti-mosquito headnets from your local sporting goods store (or, if you can find one, the full “Bug Baffler” mesh shirt). If you wear that, along with a heavy shirt (or coveralls) and a pair of gloves, you probably won’t get stung at all if you are careful. And it will protect your head and face, which is the worst place to get stung.

    Once you are properly dressed, wait until evening when all the wasps will be home. Make sure that nobody else is within about 50 feet of the nest, and that you have a clear path to retreat. Locate the exact opening that the wasps are coming out of, and give them a short shot of the insecticide spray. Then move well away. Within a few seconds, dying wasps will probably come boiling out of the nest. Wait until the activity stops, then come back in and give them another, longer shot. Repeat until the wasps stop coming out. Be sure to sweep up the bodies. Even after they are dead, wasps can still sting if someone steps on them with bare feet.

    You’ll probably have to repeat this procedure about a week later, because there will be a lot of wasp pupae that are so well-sealed into the nest that they won’t be killed by the spray. Once these mature into wasps, and you kill them, that should be about it for the wasps.

  16. David permalink
    September 1, 2011

    The nest is hanging from my ceiling on the porch I can see the nest it is smaller therm a pool ball there are about 5 to ten of them. How many tines should I do it

  17. September 2, 2011

    David: Ah! If you can actually see the nest, it is even easier, and if they are those nearly-spherical grey nests then they are almost certainly yellowjackets. There are a number of wasp and hornet sprays that shoot a thin stream of insecticide, so you can kill an exposed nest without ever even getting particularly close to it. And, once you kill off the adults, then you can just pick off the nest (wear gloves so you don’t get insecticide on your hands), seal it in a plastic bag, and throw it away.

    You can even do it without insecticide (although the protective clothes are really recommended if you do it this way). A number of times, I have just taken a spatula and a wide-mouthed mason jar, carefully put the mason jar over the nest, and then slid the spatula between the mouth of the jar and the ceiling until it cut off the nest and dropped it in the jar. Then I carefully brought down the jar (keeping the spatula over the mouth to keep wasps from getting out), and quickly put the lid on it. Then I could just pop it in the freezer overnight to kill all the wasps and larvae, and that was that!

  18. Alice permalink
    December 30, 2011

    I would like to acquire some blue mud dauber wasps as black widow control. How would I purchase some. I live in Northern California.

  19. December 30, 2011

    It’s an interesting idea, but I have no idea where one would go about purchasing blue mud daubers. The only real options might be to either (1) find somebody that already has a lot of mud dauber nests in their attic or eaves, and carefully collect them with a putty knife to place them where you want, or (2) set up conditions to attract the ones that you already have in the area. Maybe provide them with a moisture source, and some appropriate nesting sites?

    Since they mainly re-use nests build by other mud dauber species, it might be tricky getting them established in a particular spot. Although, it might be possible to make your own ball of mud, poke cylindrical holes in it about two inches long with a pencil, and stick it in a warm, protected spot. I have no idea whether or not it will attract them, but it’s worth a try.

    By which I mean, I should try it. Here, I’ll just put it on my calendar for, hm, how about the middle of May . . .

  20. Wendy permalink
    February 25, 2012

    Hi,
    Thanks for all of your information on your site. I’m hoping you can help me. I have what looks like blue mud wasps living in my house plants. The plants were infested last summer while they were outside. Before I brought them in I did poison them with multi purpose insect killer in hopes of not having them inside. Up until a week ago it had worked. But now the eggs that were still in the plants are hatching (I had expected this in the spring and planned on repoisoning then if needed). With it being still very much winter here (Colorado) I can’t put them outside and repoison. I know they are non agressive which is great but Im finding them crawling on the floor and inside shoes. I know eventually my daughter or I will be stung and I’m allergic so I would really like to avoid this. Any sudgestion on catching the adults? Would a wasp trap work? I really don’t want to have to get rid of all of my house plants.

    Thanks!!

  21. February 26, 2012

    Wendy: I wouldn’t expect poison to work on mud-wasp nests, because they lay their eggs in mud capsules that are pretty well protected from any sprays you might put on. It sounds like they have just hatched out early, because your house is warm enough that they think it’s spring.

    As for what to do about them, they’re probably only going to hatch out for a few days. If your plants are small enough, could you put a cloth bag over them? Maybe get some of the “tulle” mesh material that fabric stores have for making veils and the like, and just tape the edges to make bags to put over the plants. This will let the light and air in for the plants, but will catch any insects that come off of them. Then, when you see wasps in one of the bags, you can just take the whole bag off of the plant and set the wasps outside to freeze, and you won’t have to touch or spray them at all.

    And if you have a wasp that gets loose in the house, I’d recommend using a pair of long scissors on them. They tend to go to windows, so just come up on them slowly with the scissors, and snip them in half. This works a lot better than swatting them with something, because if you miss the snip they don’t get very alarmed and you can just try again, but if you miss with a swat they are likely to get mad and come after you. I’ve gotten rid of troublesome wasps with scissors many times, and it has always worked great and I’ve never been stung while doing it.

  22. goshawk1974 permalink
    August 10, 2012

    I saw a Blue Mud Bauber carrying a cricket in Yuba City,Ca. last weak. It could only fly 3 feet at a time. I thought it was different than anything I saw before. It left the cricket, flew arond round my legs and landed back on it. A friend then tried to kick it but the insect flew off and landed back on the cricket. The second time he tried to kick it, my friend crushed the cricket. The wasp flew back to the cricket, looked up at us , then flew off lightning fast, away. I called my son Anthony and told about the wasp. He said he saw one fly down and grab a tiny Blue Bellied Lizard and fly off with it.Is this a Blue Mud Dauber? Anthony said he also seen one digging in the sand next to a river.

  23. November 18, 2012

    i live in sault ste marie ontario i been seeing these giant blue wasps the last 2 summers when i was a kid i never saw them before what kind of wasp is it?

  24. November 19, 2012

    Jason:

    If you’ve been seeing blue-black wasps that are even bigger than the Blue Mud Daubers, they could be Great Black Wasps, Sphex pensylvanicus. The females are almost 3 cm long (compared to more like 2 cm for the Blue Mud Daubers), and they hunt katydids and other large grasshoppers. I’ve never seen one myself, but BugGuide shows them having been caught all through Michigan and Ontario.

  25. Matt permalink
    June 18, 2013

    So the other day I saw what looked like a wasp flying around my umbrella on my backporch. I looked a little closer and noticed it was blue and black with blue wings. So I looked it up and behold the first thing I got was the black flower wasp which is only found in Australia. Well since I live in Illinois (US) and not Australia I went back to google and found the blue mud dauber. Well after inspecting my big umbrella I saw 5 of these guys just flying around. I decided to open the umbrella and to my surprise their was a whole colony just hanging around. No mud and no hive. So my question is I really dont want to kill these guys since they dont bother or hurt anyone, just relocate them somewhere thats not my umbrella. How would I do this?

  26. Cee-Zee permalink
    July 8, 2013

    I’m so glad I ran across this article. We have two Northern Catalpa’s planted around our rental house in southern Ontario. They are swarming with these – literally there are upwards of 50 per tree. I figured they must not sting very often – since we walk by these trees daily – and I’ve taken many photos of them. They are incredibly beautiful, with lovely blue wings too.

    I’m making no plans to get rid of them and have yet to locate their nests. Likely in the attic or someplace we don’t go – and it is always good to keep things in balance. They might be attracted to the neighbour’s pond.

    Since they don’t seem to harm anyone – or it is more rare for them to sting – I will just leave them alone 🙂

  27. Jeffrey Hendricks permalink
    August 8, 2013

    I live in Ottawa, Ontario, Canada and was just sitting outside on the steps when I saw this black wasp with this amazing blue-metallic shine to it. I’m a Forest Officer and have some knowledge of forest entomology which only deals with problematic insects mostly unless you’re studying more into the ecological aspects of it. Nevertheless, I don’t recall ever seeing this kind of wasp in this area before, if my memory serves me right, which is not as efficient as it use to be. hehe

    I’m curious to know what the normal habitat distribution would be for this species of wasp? I for one wouldn’t mind seeing them around here more often being how beautiful they are, and seem to be pretty passive compared to other stinging insects.

  28. Jackie permalink
    August 8, 2013

    We have them in central IL. They tend to get closer to people than others but aren’t angry, more like curious. Not too many this year since it has been cool. I have a nest of yellow/black paper wasps which is new to me. We usually have dark ones, daubers and hornets.

  29. joe madajewski permalink
    August 18, 2013

    All of a sudden blue wing wasps; forget the technical name; they are flying or buzzing in their circular pattern above my lawn a few inches; they don’t seem to care who is there; I CANNOT for the life of me locate WHERE they might have dug in the ground and created a nest
    They seem to appear around 10 AM then after a while disappear ALL DAY.
    This year neighbor planted Sunflowers and I did ROMA tomatoes; the ONLY thing different that may attract them?
    I live IN NE PA; 18634 zip code; NEVER saw these before this season

  30. August 20, 2013

    Joe: I think what you are seeing is a mating aggregation of male wasps. I’ve seen this sort of behavior a few times with “cellophane bees”, and I understand that a lot of bees and wasps do something similar. What they do is find a flat, open area with some sort of landmark, and then they cruise around it like you describe until a female comes by. They then fight to mate with her.

    Since they are most likely solitary wasps, and these are probably males, I wouldn’t expect there to be a “nest”, as such. The females will each have an individual hole that kind of resembles a small anthill, and they may not be particularly close to the spot that the males have staked out.

  31. Mike N permalink
    August 26, 2013

    In Royal Oak, MI- I have these same wasps by the dozens coming and going all day long atop my very large compost pile. It is actually interesting watching them dig their heads down and load up with mud. I have a large garden and would prefer the spiders not be depleted as I don’t use pesticides because of all the other bees that are attracted to my flowers, especially my patches of Joe-pye that I keep just for the many species that abound on it. Cant find a nest anywhere and they seem to fly in all different directions when leaving the pile. At any given time there are as many as 15-20 at a time gathering mud so there must be quite a few of them. I want my Kate and Edith too, so any suggestions?

  32. August 26, 2013

    Mike: They are probably nesting in eaves, attics, and similar dry, protected places, and since each one has her own nest site, it won’t be obvious where they are going to.

    The spiders that they prey on probably eat more pollinators and other beneficial insects than pests, so having the wasps around is not likely to affect your natural insect controls.

    (the mud-dauber nests that I have cracked open tend to be stuffed full of crab spiders. Crab spiders mostly hang out on flowers, and grab the insects that come by to pollinate the flowers. They don’t very often eat the insects that really cause trouble in the garden, like caterpillars and aphids).

  33. Joe Madajewski permalink
    August 26, 2013

    OK TIM
    The dogs are oblivious to the blue winged wasps and they care less when I walk in the yard
    I wont bother to kill them especially if they are benficial; and dont bother a soul
    I see them every day and NO EVIDENCE of any female lairs
    Suprised they just ‘showed up out of nowhere’; been living here 54 years!!!
    Again the ONLY difference neighbor has about 50 10 ft sunflowers (attracting finches I NEVER saw here in 54 years) and planted ROMA tomatoes aqlso geraniums to keep the mosquitos away
    so I dunno if dumb luck or some combination of what was planted attracted them. Their tech name I cant remember but transparent blue wings; orange fuzzy abdoemn then two roundish spots near the END of their abdomen forget the color…

  34. August 28, 2013

    Joe:
    Whatever they are, I’m not familiar with them myself. The only waspish things I can think of with orange, fuzzy abdomens would be males of some of the Velvet Ant species (female velvet ants don’t have wings, and look so different from the males that it is hard to tell they are the same species). BugGuide says there are 480 velvet ant species in North America, and practically none of them live up here (although a bunch of them live in Pennsylvania).

    In any case, male bees, ants, and wasps don’t have stingers (only the females sting), so I doubt that these are going to bother anybody.

  35. Joe Madajewski permalink
    August 28, 2013

    Tim

    One more time 😉

    Blue-winged Wasp Scolia dubia (found using query using GOOGLE images)

    THIS IS the one buzzing around and I won’t bother them; NOT EVEN to trap in a bottle; they bother NOTHING and care less me or the dogs are in the yard
    Sites say they are beneficial so who am I to argue 😉

  36. Scout permalink
    June 13, 2014

    Hey Tim, we have a Mud Dauber nest on the eave on our house, and it DOESN’T MATCH any pics of nests, and since you seem to be quite the expert,. we would like it if we can send you and email of the nest, it looks like an old fashion light bulb with a tube sticking out of it, please message back, and put why they aren’t that lethal to humanoids, also we have BOTH yellow-black Mud Daubers and blue Mud Daubers flying in and out of it, although it is mostly summer, and I have a question, can we take down the nest and put it some where would it be ok? please put a message back, thank you.

  37. July 1, 2014

    Last two years after much research found out what was in the yard and this site
    This appears to be (?) year three and so far NO Wasps to be found
    They used to come ‘out’ say at 10:00 AM and fly around in their figure 8 hovering over the ground and bothering NO ONE, so I didn’t do a thing. DO they ‘disappear’ after a number of years naturally and take up residence somewhere else?

    Joe

  38. July 1, 2014

    Joe:
    I’ve noticed this with a lot of insects, wasps included – one year they will be everywhere, and then they will practically vanish for several years, then they may come back again at unpredictable intervals. I think what happens is that they build up their numbers when conditions are good, but then when they get a high population density they attract parasites and spread diseases from one to another, which wipes them out locally until fresh ones can come in from other populations. So you are likely to see your wasps again someday, but it could be a while.

  39. July 1, 2014

    I am GLAD I found this site last two years; otherwise I’d probably look to eradicate them…your site says what they do and they do just that; bothering NO ONE; attacking no one; so who cares they fly around…NOT ME !

  40. Jean Holzinger permalink
    July 18, 2014

    While weeding my garden, I watched a blue mud dauber land in a spider web. It moved around a bit, as if it were caught. When the spider came out from hiding to grab it, the wasp quickly grabbed the spider and flew away with it. I Thought this was very sneaky.

  41. myah permalink
    August 5, 2014

    My uncle got bite sting or what ever by a blue wasp when my grandmother were running. They sat down on a bunch then like 10 blue wasp came out and bite, stung or whatever they do. My grandmother was hitting them with her towel to hit them off. Do they also put their nest under park benches?

    XHTML

  42. July 27, 2015

    I got stung bit by one yesterday on my ankle and it hurt like crap immediately and later that day my ankle and 12 – 16 inches up my leg hurt and got swollen. This morning my leg/same area is yet swollen and numb and was hard to walk across the floor. I have been stung by other wasp without such of a problem as the blue was did to my leg. I can find no info about the first aid of the blue wasp or anyone having such a problem as I have by the sting of one. I say that they have a much more potent sting than any bee that I have been stung by.

  43. Myrt permalink
    July 27, 2015

    We have blue wasp on our back porch. We have a rodiron spiral decoration with a blue glass ball in the spiral hanging on the eave of the porch. Before nightfall the blue wasp gather on the blue glass ball but as soon as the sun comes out in the morning they all fly off to their unknown destination.

  44. Chris Snell permalink
    June 18, 2016

    I just took pictures of what looks like these blue mud daubers. They are on wood at our loading dock. They are there every summer BUT these don’t have a (mud) nest. They just hang on the side of a support (wood) beam. We do not have a pond or body of water….could they be something else? Something similar? My husband thinks they r flying ants but they look a lot like the pictures above.

  45. william strunk permalink
    August 16, 2016

    I am 85 years old and had never seen blue wasp until 4 days ago. I spotted one out back in a fight with a yellow jacket. The Yellow Jacket was definitely the aggressor. The two would mix it up. then separate, and the YJ would attack again. This went on for many minutes. I had to call my wife out to witness the confrontation.

  46. August 16, 2016

    The sting from a blue wasp was extremely painful and last for a few days.

  47. Teri permalink
    March 13, 2017

    There’s a mound of dirt on my outside wall and it has little holes at the bottom.Is that a nest?

  48. March 14, 2017

    Teri:
    It probably is a nest, yes. There are a bunch of different kinds of wasps that make little mud nests, and they all look different, so any lump of dried mud you find on the wall or stuck into a crevice is likely to be a wasp nest.

  49. Armando Landa G. permalink
    April 14, 2017

    There’s a couple of blue wasps that comes every day to take water for their mud. I consider them pets, yes, pets! They acknowledge having clean water every day in our small fountains by flying around me!

  50. Suzanne Somers permalink
    June 16, 2017

    Hi! So I looked these bad boys up because I witnessed one chasing a black widow spider on my driveway and then flying off with it! I live in CA. It was incredible, I didn’t know any other bug could eat or kill a black widow!

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