Female Broad Necked Root Borer

what is this bug
Found this guy on the rock wall in our yard. He was approx. 3 inches long (didn’t want to get too close w/ the tape measure). Everytime someone came close to him a long stinger would come out the back and a clear liquid would run along it to the tip. With the stinger he was approx 4 inches long. Is this bug poisonous? If there is one is there usually more? I appreciate any info. Thanks.
Denise

Hi Denise,
This looks to be a female Broad Necked Root Borer, Prionus laticollis. BugGuide has a photo that indicates scale. The stinger you mention is actually her ovipositor. Eggs are laid deep underground. According to BugGuide: “Eggs are inserted into ground (or under litter) in groups. Larvae tunnel downward to feed on living roots of a variety of trees and shrubs. At first they may feed on bark, but then proceed to hollow out small roots. Pupation occurs in spring, about 10 cm under the ground. Life cycle probably three years.” They are not poisonous. They are found in the Eastern U.S. and there are no recent reports from Florida, perhaps due to global warming. We wish you had included a location in your letter.

107 thoughts on “Female Broad Necked Root Borer”

  1. Hello I just found one in Philadelphia, Pennsylvania. Just wondering can they hurt you at all or do or are they somewhat friendly?

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    • The jaws of many wood boring beetles are quite powerful since they need to be able to chew their way out of the wood they have been burrowing in for the time spent as a larva. Large Borers might actually be able to draw blood if they are carelessly handled and they bite.

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  2. Just found one one my porch in Jacksonville, Fl. Sorry to say it did not survive. I thought it was a Palmetto bug and sprayed it.

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  3. Hi helpful bug friends,
    I have these beetles in my back yard. Will they damage my trees (which are huge and beautiful)? Are they damaging like emerald ash borers? What should I do, if anything?

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  4. I live in Minnesota and found one yesterday, August 4. As I was looking at it, it swung under the stem it was sitting on. As it swung under it sprayed a liquid out in an arc. Was wondering if it was urine or a chemical deterrent ?

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  5. Hello*** I’m over welded with this ugly huge cock a roach lookin beetle..I’ve had them in my yard for 6 yrs. I have killed at least 150 of them.collected them for insect comanies? Nobody knew what they were? They usually come in june* but more so when it’s hot. I wasted 600.00 dollars to a tree arborist company wich did nothing!! I called health dept. In my town..I need yur help? I poured ammonia down the 2 in hole they dig..gas! Bleach. I can’t get rid of them!!! Wtf. Please help me! Sincerely. Mike t violette 2039824606 from wtby conn 06705-1808

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  6. They are broad neck route borer. They are ugly…they are all over my lawn.they are in the town of waterbury ct. All over..seems like they are growing rapidly! I have huge oak & maple trees in my yard…When my mom” was alive she said they were June bugs! But now this nitemare is called broadneck Rte borers. . Please help me find poison that will kill these beetles for good! !! I wasted so much money..and I have no help. .. I’m do upset over these bugs!! Why my yard? Why me?, you step on them* they still don’t die.. Please help. Mike t violette 2039824606 from wtby conn 06705-1808

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  7. Sorry to keep going on here!! I had a large bucket filled with them? Like 50 of them.. it’s like a Sci – Fi movie come to life!!! Invasion of the broad neck route borer. ……. Please help. Mike t violette 2039824606 from wtby conn 06705-1808

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    • Your rudeness at the free identification services we provide is duly noted. We are not responsible if our readership crank calls you on the telephone number you willingly provided on one of your comments.

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  8. Found one in West Babylon, NY. Found it near two small holes dug into the ground, is this where it laid its eggs? The holes and the beetle were found on the surface near a tree, if that helps.

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    • According to BugGuide: “Eggs are inserted into ground (or under litter) in groups. Larvae tunnel downward to feed on living roots of a variety of trees and shrubs. At first they may feed on bark, but then proceed to hollow out small roots. Pupation occurs in spring, about 10 cm under the ground. Life cycle probably three years.” That sounds consistent with your sighting.

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  9. Hello* well I apologize for my harsh words…I’m really upset about these bugs!! I need help? I just killed 10 of them…There has 2 be a poison to kill them off^ Thank god their not eating my house!!) Lol. Please help me find a solution here! Nobody wants these horrible beetles in their yard… thankyou mike t violette

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  10. The males are smaller!! They fly. Females font fly. They resemble huge cockroaches!! On steroids. .lol. I spent 650.00 to a tree arborist in Watertown wich he didn’t know his ass! From his elbow? Mike t violette

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  11. Yes*** the female does not fly….males fly…I put them in a bucket of water. .and they drowned to death.?

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  12. I just found one in my screened in porch in Clearwater FL. I think it was already dying because it was on its back and its stinger was sticking all the way out. When I touched it with a stick, the stinger went back in. Weirdest bug I have ever seen and we see a lot as we are near a stream and a lot of trees and foliage. By the posts above, only 1 other one in Florida, and that was north Fl. Do they migrate?

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    • Broad Necked Root Borers do not migrate. Though BugGuide does not list the Broad Necked Root Borer in Florida, the very similar looking, related Prionus pocularis is found in Florida, according to BugGuide.

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  13. Well folks! I’ve been dealing with these cock roaches^ on steroids for 5 yrs now! All you people wanna do is say? Oh I found 1 in my yard. Nobody has a solution to killing these f cking!** things?? Like the person in charge of this app.? Or what ever the he’ll this is for… you want them for pets! Cause I don’t. . Give me yur solution! !! Thanks. Mike t violette

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  14. I just found one in waxhaw north Carolina. I run my photo studio out of a 160 year old building. One of these is laying belly up with stinger out and white larvae all around her. Ive called my husband to remove it.

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  15. I live on Cape Co, while inspecting my lilies for red lily leaf beetle, I saw this horrid Borer on the stem of my asiac lilly, never have I seen one before yesterday. So I sprayed the heck out of it with a bug killer. Also, there is a 2 inch wide hole right at the base of the plant, I was thinking maybe the chippy’s, could it be the tunneling of this horrid creature? Thank you

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  16. I have a backyard full in Chicopee ma. One bit my neighbor and drew blood so know they bite. But are they harmful if ingested? My dog brought one in and was gnawing on it like a bone.

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    • Probably a good source of protein for your dog. Not poisonous, but as you noted, they have strong mandibles and they could bite your dog’s tongue.

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    • Where do these things come from? Are you going to spray or do anything? I tell ya they are nasty, although I’ve seen only 1 her on Cape Cod, I know there must be more lurking somewhere and I want to be ready. Please post what you end up doing.

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  17. Never have seen a bug that big and scary looking yikes went to pick up water hose there it was!! Cumberland Rhode Island

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  18. Ugh upstate ny here, my jerk cat spotted one and was too afraid to kill it, so I tried about five times to squash it. They are tough! I deposited it in the toilet and it was STILL clinging to life, it’s jaws were also opening and closing and LARGE and terrifying.

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  19. I found one of these in my garage last night a d tonight in my house! Please help! Do they bite? Do i need an exterminator? Are they going to keep coming in my house??

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    • Root Borers have powerful mandibles and they might bite if carelessly handled, but they are not aggressive. You do not need an exterminator. We are not prescient and we cannot predict the future.

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  20. Just found one in Nederland, TX. Huge, ugly thing! Went to grab the closest thing I could to spray and kill it. FYI- febreeze works well.. lol

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  21. I know this is somewhat an old post, but I am in Georgia and these things are flooding my home. I’m not sure if it’s because we didn’t necessarily have a winter, or what, but this is the first time I’ve ever seen one. About a month ago we had the first one show up – dead, from our spraying the home. But tonight alone I found 3. They’re creeping me out!

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    • According to BugGuide data, the Broad Necked Root Borer is not reported west of Indiana. We suspect you have another member of the genus Prionus. Though it is not identified to the species level, BugGuide does have this image of a member of the genus from Wyoming and we have a posting in our archives of Prionus emarginatus that indicates it is found in Wyoming.

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  22. My dog acted like his foot was stung and we found one in the same area. This is the first I’ve ever seen one of these beetles. Does the female’s ovipositor act as a stinger? He may have been bitten though. His foot is swelling up, but everything I’ve found on this beetle says it isn’t poisonous. Could you please verify this?

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  23. Sue…you keep listening to this bug,forum guy! He ain’t gonna help you! I now have the knowledge, that he lacks, he loves them! Where we hate them…. only method of killing them,is putting them into bucket of water….: ALSO LOOKING INTO ANOTHER METHOD OF KILLING THEM! CALLED EARTH DIATIMAS..WHITE POWDER! THAT YOU THROW ON YUR LAWN***AND IT EATS THIERRY SHE’LL LIKE ACID…MAYBE OUR BUG! FORUM GUY! WILL LOVE THAT….LOL

    Reply
    • Christ why are you still here? Would you go to a surgeon, physicist, or a news reporter and flip out if at them for not giving you extermination advice? Just because the people here know about entomology doesn’t mean they know about or are obligated to give you pest control advice, it’s not their job. There are plenty of places for what you’re asking for. Example:
      http://www.pestcontrol-forum.com/#/en/Home/
      You have no reason to be here. Please leave, your comments make you look like an angsty 12 year old throwing a tantrum.

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      • Thank you. We have been ignoring this troll. Right above the ad space on our homepage, we state “What’s That Bug? does not endorse extermination” because we have no control over exterminators taking advantage of google ads on our site.

        Reply
    • Christ why are you still here? Would you go to a surgeon, physicist, or a news reporter and flip out if at them for not giving you extermination advice? Just because the people here know about entomology doesn’t mean they know about or are obligated to give you pest control advice, it’s not their job. There are plenty of places for what you’re asking for. Example:
      http://www.pestcontrol-forum.com/#/en/Home/
      You have no reason to be here. Please leave, your comments make you look like an angsty 12 year old throwing a tantrum.

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    • Mike, serious question … are you stupid? Because that’s the impression you’re leaving on everyone who has ever visited this page for information.

      I can explain it to you, but I can’t understand it for you so I expect I’m wasting my time.

      Bugman, visiting the in-laws on Long Island and just had one of these scare the bejeesus out of me. Thanks for the info.

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    • Mike, serious question … are you stupid? Because that’s the impression you’re leaving on everyone who has ever visited this page for information.

      I can explain it to you, but I can’t understand it for you so I expect I’m wasting my time.

      Bugman, visiting the in-laws on Long Island and just had one of these scare the bejeesus out of me. Thanks for the info.

      Reply
  24. Found in North Andover, MA. Emerge from under an oak tree every summer about the first week in July. Tend to be a favorite food of the Barr Owls.

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  25. Found a male today in Eastern Pennsylvania, dry, lightly forested area. Kept trying to fly away but wasn’t able to, just opening his wings and buzzing/vibrating his body, then scuttling along the ground angrily. Haven’t seen one of them before so I’m quite curious. He doesn’t look hurt at all so I’m not sure why he couldn’t fly.

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  26. We found a dead female in our driveway this afternoon, we’re in Colorado Springs. Rolled over on her back, ovipositor was out, looked like she just couldn’t take the sun.

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  27. Just found one in my kitchen, Ardrossan, Scotland. With the ovipositor out, are they harmful? I have a baby who is on the floor a lot.

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  28. I just found on in Anderson, South Carolina. I was walking at night through the yard and it made me jump. When I stepped on it the inside was white and gooey. Any idea what that stuff is?

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  29. Hi I just came out side on my porch around 12am an saw my first broad necked root borer an I live in Jacksonville fl. So this bug has been sighted here too.

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  30. Just found one of these inside my house in Vale, Oregon. Very scary bug. I would like to attach a photo but not sure how to do so.

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    • Broad Necked Root Borers have powerful mandibles that they will use to bite (more of a pinch) to defend themselves. They do NOT sting.

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  31. Found one in Carmel New York. Put it in a vented jar, lived here for 35 years and have never seen one before. Should die or live.

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  32. Just caught a large female, ovipositor extended, near our back deck, Peekskill, NY. I still can’t tell if this is good bug or not… I’d love to let it go and be part of the ecosystem, but I also know it loves oak trees, and we have a few that are near or over our house – worried that its larvae will infest one of our 80+ ft. tall oaks. Damage or tree service can be $1,000’s of dollars.

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  33. We found 2 of the females in our CT yard in the past 2 weeks. Terrifying creatures! We tend to be pretty anti pesticide. I’m wondering if those of you who have had these guys in your yards- did you have a lot of damage to your trees? We have a couple beautiful old trees that we love but would be heartbroken (and bank broken) should they get destroyed from the roots up. TIA!

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  34. I just found one of these today here in Central Pennsylvania! I came searching for answers and found this post. Such an alien-looking insect! So freaky but cool! Mostly freaky!

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  35. My son found a dead one today. We live in central Georgia. Glad to hear that stinger looking thing is for depositing eggs and not stinging! Are these bugs regarded as destructive, or is their damage reparable by most trees/plants?

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