Female Broad Necked Root Borer with Ovipositor extended.

Subject: OMG – What is this????
Location: Andover, NJ, backyard
July 8, 2012 4:18 pm
Sorry to be emailing twice in one day, but my husband just showed me this monster bug and I have NO idea what it is! It was in our yard, sitting on some race-car tires. I was able to get within six inches of it to take pictures. It is a little over an inch long without the rear-protrusion. When I was able to get it to move, it dropped to the ground, rustled around in the grass and seemed to go underground. Hoping you can ID this for me!
Signature: Deborah Bifulco

Female Broad Necked Root Borer

Hi Deborah,
This is a female Broad Necked Root Borer,
Prionus laticollis, and she has her ovipositor extended.  Though it resembles a stinger, the ovipositor is an egg laying organ that has been modified into a stinger in insects like bees and wasps.  In the case of the Broad Necked Root Borer, the ovipositor will not cause any harm to humans.  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.”  The Broad Necked Root Borer is in the Longhorned Borer Beetle family Cerambycidae, and we get the lion’s share of our North American reports and identification requests from this family from June through August, especially the Prionid subfamily to which the Broad Necked Root Borer belongs. 

By the way, this is a stunning photograph.  We can’t help but to wonder if she is releasing pheromones into the air.  We are quite confident with the guess that she is.

Thanks so much for the ID, Daniel, as well as the ID on the other two bugs I spotted yesterday.  My husband saw this big girl again yesterday later in the afternoon, on the same stack of tires and with her ovipositor extended.  What an amazing looking bug!

Gene St. Denis confirms pheromone suspicions.
Daniel …, they release female pheromones this way , for mate attraction . Cheers !  Gene St. Denis   Sierra Nevada Research

10 thoughts on “Female Broad Necked Root Borer with Ovipositor extended.”

  1. I have seen several of this bug around my trees , will they damage the trees ? If so how would I get rid of them ?

  2. I have one of these on the outside molding of my front door right now. It is very scary looking, as I am not a bug lover, to say the least. Do you have a recommendation as to how to remove it?

  3. I saw this bug today. I picked it up by the abdomen. I was not bitten. I have read information this bug typically does not bite humans but you are saying care should be given when handling these particular ones? I want to make sure that I am not hurt or do not hurt it in the future. Thanks for the feedback.

    • Someone said once that if it has a mouth, it can bite. Root Borers are not aggressive, but they do have powerful mandibles.

  4. Hi, I found a large (3 inch) female here in southern Colorado. I thought they typically live east of the Mississippi?

  5. I have pictures of a female with her ovipositor extended. I can send them to you if you would like. I live in Arizona at about the 4,000 ft level


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