What's That Bug? does not endorse extermination

Feeding on Goldenrod
Location:  Southern New York State
August 16, 2010 4:18 pm
Saw this beautiful bug feeding on goldenrod in early August. It is about 1/2” long and unfurled gray wings under the colorful shell and flew short distances when disturbed. Also the unidentified wasps were busy at work. Cicada killer?

Blue Winged Wasp

HI Don,
The image of yours that we are not posting is an Ailanthus Webworm Moth, a species we have posted several times in recent weeks.  We also just recently posted an image of a Digger Wasp or Blue Winged Wasp,
Scolia dubia, but it was photographed in a tupperware, not in its natural environment like your lovely photo.  Like many wasps, the adult Blue Winged Wasp feeds on nectar while the larvae are predatory.  Since they are not terribly mobile, the female wasp provisions for her brood.  In the case of the Blue Winged Wasp, the female locates and stings to paralyze the grubs of the Green June Beetle and the Japanese Beetle.  According to BugGuide:  “Males and females have a courtship dance, flying close to the ground in a figure-8 or S pattern. Females burrow into ground in search of grubs, especially those of the Green June Beetle, Cotinis, and the Japanese Beetle. She stings it and often burrows farther down, then constructs a cell and lays an egg on the host. Larva pupates and overwinters in a cocoon within the body of the host. One generation per year in North, more in South.”  According to Mom, any creature that preys upon Japanese Beetles is aces in her garden.

Fantastic!  My daughter and I love your site.  Thanks a million.

What's That Bug? does not endorse extermination
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23 Responses to Digger Wasp or Blue Winged Wasp

  1. cory says:

    Why will these wasp not sting you they live in 2 of my baby dog wood trees and I mow and stir them up hold them in my hand can they become aggressive towards humans/children.

    • bugman says:

      This is not an aggressive species. They do not have a home or nest as an adult, so we don’t understand why you state they live in your baby dogwood trees.

      • cory says:

        All I know is that they stay in one area of my property and at sundown if you walk out to my trees you can see them almost wraping around the tiny branches and when we get up in the morning at daylight they are still there

  2. frank reklen says:

    the picture helped me make a positive I D. The only location in my yard is over the sceptic tank. They are flying in an 8 . Is there maybe a problem with my septic system?

    thanks for your help.

    • bugman says:

      Digger Wasps would not be interested in the septic tank, but perhaps the ground above the septic tank is to their liking.

  3. Donna says:

    I have these every year around the end of Aug. in NC. It seems at night or in cooler weather not sure which they rest or sleep in a small apple tree I have in the yard.

  4. Rae says:

    Yes, I have them now.. for a second year, in the very same area, about 250 of them !!! And they are ALSO flying around the septic tank drainage pipe which is well buried underground. That pipe leads away from the house about 50 ‘, and the wasps like that area. The ground is not wet, but, on the driest weeks, that area still has some green grass. They fly low, zigging and zagging around. Last year, I made a video of one wasp dragging a cicada down the hole that had previously been dug. And, the month before (July) I had noticed large green beetles, not Japanese beetles, (the rose bush and some weeds have many beetles on them munching on them steadily), but these were BIG blue – green beetles. The holes these blue winged wasps make on the lawn make that area look like a minefield, there are more holes than lawn. The area they have worked on is about 30 ‘ x 20’. Is there any way I can prevent them from returning to this spot next year? My dog is outside and yes, these are placid wasps, but, can’t they go somewhere else ?

    • bugman says:

      If the wasps find the conditions there to their liking, it is not going to be easy to persuade them to nest elsewhere.

  5. john says:

    I have the blue winged wasp in my yard and now that I know they are killing the grubs and beetles, I’m ok with it. The question I have is, can I cut grass without a trip to the emergency room? I know they are not aggressive, but would a lawn mower get them fired up? Thank you.

    • bugman says:

      We doubt it. Wasp stings from social wasps generally occur while defending the nest. Solitary Wasps do not protect the nest.

  6. Donna Andersen says:

    This year is our first year seeing them in masses around our pompadour (sp) ornamental grass. Now flying low over our lawn. We’ve never had them before. They don’t seem too interested in U.S. Or our two large dogs. There are a whole lot of them. Our unground pool is loaded with them now. I’ve saved a few but I’m nervous that someone may be stung while in the pool by one of these while struggling to get out of the water. Will they go away if I spray my lawn?

    • bugman says:

      In our opinion, spraying the lawn might do far greater harm to people using your yard for recreational purposes than the possibility that someone might be stung by a non-aggressive wasp that is not considered dangerous and is not bothering you or your dogs.

  7. Donna Andersen says:

    Sorry for the misspellings. Auto correct is so annoying!

  8. Stephanie says:

    I think these, too, are Digger Wasps. I just took these this morning with my iPhone camera. This one is in my front vegetable & fruit garden, it likes my ripe raspberries a lot. I am terrified because I am lethally allergic to bee and wasp stings. I always carry two epi-pens with me… because without them, I will stop breathing in 12 seconds after being stung, and again stop breathing 15 minutes after the first epi-pen injection if I don’t use a second epi-pen. How dangerous is this thing to me? I’d love for it to eat the Japanese beetles… but I don’t want it to kill me. :-/ It has a companion or two, also. (There are two or three out there in my garden. Never seen them before, and I’ve had my garden in the same place for 25 years.)

  9. Stephanie says:

    Hmm. Seems I can’t get my pix to come through???

  10. J says:

    Thanks for posting, I am so happy to finally be able to identify this insect! We’ve had a problem with Japanese beetles for years and this year, nothing. Instead we have had all these mellow, low-flying wasps. They don’t seem to land much so I haven’t gotten a good look at them until today when I saw one in the grass. We have so many of them but I walk right through them and they’e never bothered me, so I figured they were pretty harmless. Awesome to know that’s what got rid of the beetles! I hope they stick around next year.

  11. Rae says:

    Yes, now that I know all about them… I welcome them.. knowing that they are harmless and actually enjoy watching them flying around. The males are looking to catch a female.. and they are all going around as predators for grubs. The leave holes .. excavating them in the lawn.. and now.. I don’t care.. I know they are not around for long.. and even my dog just ignores them.. and they ignore her as she sniffs around looking for anything of interest. DO NOT NOT NOT leae anything insecticide.. for these are very beneficial insects.. and will only sting you if you grab one and pull on it.. or squish it.. or cause it tremendous harm.. Other than that.. you can identify them by the two yellow spots on the back..and those blue wings that shine… Leave them alone.. and let them do their jobs.. Yeah for them !!!!
    They do nest in a huge azalea bush near to the site where they go around ground zooming.. I watch them go back and forth.. and in the morning, when they wake up… I actually watch them leaving the azalea bush. It stands over 6 feet tall. They have never been angry at me, and have no hive to defend.. They are peaceful and neat to observe. Enjoy and leave them alone !

    • bugman says:

      Thanks for your strong endorsement of tolerance of the lower beasts.

      • Rae says:

        You are welcome.. Mike McGrath.. from You Bet Your Garden, NPR.. WHYY.. Saturday and Sunday morning.. he helped me.. Knew him in college.. and he asked a student from Del Val U. to come over to see them in person.. I have about 200 of them.. or so. Can’t make an accurate count, they don’t stay still for a second. Totally harmless and neat to watch. I now sit outside with my dog and watch them do their thing. Nature is super.. just let it be.. it will balance out. At first, I was freaked out. Was severely stung three times by yellow jacket wasps., three different times , bad news for me. had to have a pro come out and remove the new hive.. twice. They are very agressive and do protect their hive at any cost. But, these are different.. So to everyone.. you will know them.. they fly very low, zig zag around. easy to identify. And, they do ignore you.

  12. Rae says:

    correction to my type-o.. do NOT NOT NOT NOT USE ANY INSECTICIDE ON THE LAWN… YOU WILL NOT ONLY KILL THE JAPANESE BEETLE GRUBS, BUT, ALSO THE BABIES OF THESE WASPS.. and you don’ t want to do that. Let these wasps do that for you.. they will kill any bad grubs you have in your lawn. And, they do a perfect job.. and no insecticide / poison is used.. These ground wasps are very beneficial.. so just LEAVE THEM ALONE.

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