Are you looking for natural ways to get rid of root borers in your garden? In this article, we will answer what eats broad necked root borer and why they are such a big menace.
Broad-necked root borers are tree pests that are known to attack and destroy the roots of plants and trees.
These tiny beetles feed on the tree from the inside out and are tough to spot.
They are fed on by common predators like certain ant species and beetles like the Jepson’s beetle.
Birds are also commonly known to feed on these bugs.
It’s important to keep your plants’ surroundings clean so that these beetles are easily spotted by their predators.
This helps a great deal in keeping an infestation off your hands.
How To Identify Broad Necked Root Borer?
The broad-necked borer, also known as Prionus Laticollis, is a pest from the family of long-horned beetles.
They are known for attacking the root systems of plants and trees (hence the name).
Broad-necked root borers are often confused with the Asian longhorn beetles, but there are major differences between the two bugs.
Broad-necked root borer beetles have fuller body that appears to be somewhat flattened.
They are blackish or reddish-brown in color with short antennae, and females have a very visible ovipositor.
Adult beetles can grow up to one and a half inches long. Among these nocturnal bugs, the males are seen flying, while the female broad-necked root borers do not.
What Damage Does Broad Necked Root Borer Do?
Broad-necked root borers are notorious tree pests that can cause severe damage to trees upon infestation.
They commonly attack deciduous trees but are also considered pests of oak, pecan, dogwood, hickory, and fruit trees and shrubs.
Because the beetle exclusively feeds on roots, there aren’t many obvious signs to point to an infestation.
The few signs you can notice are
- The foliage thinning and becoming yellow.
- Some branches may start to die and fall off.
- You might notice the bark and trunk of your tree full of small holes or cracks.
A root borer attack can easily destroy a young plant.
As for older trees, an infestation could render them supported only by a root or two, making them susceptible to being blown over.
The sure shot way of knowing if you are dealing with a root borer infestation is to uproot the tree and check.
If you find the presence of substantial honeycombs in the roots and crown, that would be evidence that you have a root borer problem.
Apart from being tree pests, these insects are not poisonous or harmful to humans in any way.
Where Does it Live?
The broad-necked root borers are widespread across North America. They’re found in New Jersey, North Carolina, Minnesota, and Oklahoma. They’re also found in Quebec and Ontario.
These tree pests are mostly native to deciduous trees in forests, but they also love feeding on fruit trees such as apples, pears, and peaches.
You may also find them in other varieties of trees, such as oak, hickory, and pecan.
You can often spot these bugs at a tree or plant’s base. They are also seen loitering around the plant debris and leaf sheaths.
What Eats This Bug?
This bug has some of the most common predators of insects in the food chain.
They are preyed upon by some ant species and beetles, such as the Jepson’s beetle, also known as Plaesius javanus.
The broad-necked root borers usually feed on the roots of trees and therefore are tough to spot on trees.
But if you keep the area around your plantations clean, you might be able to spot them and prevent their infestation.
Clean surroundings make them visible to bird predators, keeping the risk of a root borer infestation at bay.
What Are The Other Preventive Measures You Can Take?
Keeping your plants and trees healthy is the primary way to ensure these bugs stay away.
Root borers usually attack shrubs and plants that are weakened. The infestation further leads to the destruction of the plant.
Here are some practices that will help prevent this menace from spreading in your farm or garden.
- Regularly prune and trim your plants.
- Cut decayed and yellow leaves and branches so your plant/ tree thrives.
- Make sure you seal the cuts with a prune paste to quicken the healing process for your plants. Sealing holes will also prevent root borers from entering the trunk.
- Avoid littering near your plants and clear debris and overgrown grass from the ground from time to time.
- Keeping the surroundings clean will not leave any space for the root borers to seek shelter.
- One important part of keeping your trees healthy is feeding them strong organic fertilizers.
- If you find signs of infestation, surround your trees with mulch, water, and fertilizers. This will penetrate the ground, reach the roots and prevent the borers from causing further damage.
- If any tree or plant has been infested significantly, the best way to avoid the spread is to uproot it and replace it with a new one.
- Treat your new plant with a contact insecticide to avoid re-infestation.
Frequently Asked Questions
What do broad-necked root borers eat?
Broad-necked root borers usually feed on deciduous trees. It is also considered their natural habitat.
However, root borers also attack other trees such as oak, dogwood, hickory, etc.
They’re also known to feed on grape vines, fruit trees, and shrubs of fruits like peaches, apples, pears, etc.
How do you control root borers?
With root borers, prevention is much easier than controlling or treating. To prevent an infestation, regularly clear plant debris and fallen leaves.
Treat your plants and roots with the right organic fertilizers to keep these bugs away.
Regularly prune and trim the foliage to get rid of weakened parts. A healthy plant/tree will never attract root borers.
Can broad-necked root borer fly?
Among the broad-necked root borers, the males are often seen flying. They’re usually attracted to light and, being nocturnal, venture out at night.
On the other hand, the female root borers do not fly even though they have wings. This could be because of their bigger size compared to their male counterparts.
Where do broad-necked root borers live?
Broad-necked root borers are native to deciduous trees but can also be found on oak, fruit trees, and shrubs.
They infest the root systems of trees and plants and hence are tough to spot. But you can find these bugs at the base of plants or sheltered in plant debris and among leaves.
The broad-necked root borers can be big pests for the trees in your garden. If you spot an infestation of these bugs, you should take immediate action.
While insecticides can always work, we would not suggest that you use them. They can harm your crop and kill beneficial insects in your garden.
They have common insect predators, such as birds and certain species of ants and beetles. The Jepson’s beetle, or Plaesius javanus, is also one of their commonly known predators.
Thank you for reading!
Identifying broad necked root borers is itself often a challenge, because they remain hidden in the ground.
Several of our readers have sent in letters over the years asking us to identify what this bug is many.
And many also wanted to know how to get rid of it, or what kind of insects predated it.
Please have a look at some of these letters below.
Letter 1 – Broad Necked Root Borer
Can you please help us settle a neighborhood bet? We are debating whether this is a cockroach or a type of beetle. We live in upstate South Carolina and this was found on a deck near a swimming pool. Any help you could give us would be appreciated. Thank you,
P.S. We were also wondering, is a cockroach a type of beetle?
This is a Broad Necked Root Borer, Prionus laticollis, a beetle. Cockroaches are not beetles.
Letter 2 – Broad Necked Root Borer
we found what I think is a type of beetle . . . but can’t find any information about what kind of beetle it is — can you help us? My wife found this beetle in her backyard when she was planting flowers. Thanks,
This is a female Broad Necked Root Borer, Prionus laticollis. 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.”
Letter 3 – Broad Necked Root Borer
Subject: Really BIG beetle
Location: Norfolk, MA
June 28, 2012 7:14 am
Hi–I’m attaching a few pictures of a really big beetle we found on a family walk last night. It was walking on the street, then went into the leaves, weeds, tree debris and pine needles on the shoulder. We live in Norfolk, Mass. We caught it in a jar and brought it home, where it captured the attention of both our dog and cat. It’s nearly 2 in. long, and We set it free the next day…We’re new to the area and all of its insects (June bugs, ticks, yuck), but we’re interested to learn what this was.
Thanks a lot.
Summer is the season for large Longhorned Borer Beetles and your individual is a Broad Necked Root Borer, Prionus laticollis. You can read more about the Broad Necked Root Borer on BugGuide.
Letter 4 – Broad-Necked Root Borer
Subject: large 2” beatle
Location: Fairmont, West Virgina
June 25, 2013 8:27 pm
I saw some of these last year around the same time ( June, July). I see them around an old rotting stump with their tail ends in the air, or just running along the ground. I live in northern West Virginia and thought they may be hardwood stump boring beetles, but I didn’t think we had them this far north. They are probably the biggest beetles I have seen in person. Is that what these are, and are they supposed to be this far north?
This is a female Broad-Necked Root Borer, Prionus laticollis. The reason you have seen them around an old stump is that the larvae are borers. 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.” BugGuide reports sightings as far north as Maine and they are also found in Canada, so your West Virginia sighting is not unusual.
Letter 5 – Broad-Necked Root Borer
Subject: Large black beetle in CT
July 4, 2013 4:46 pm
Whatt is this bug???
We just found this large back beetle in our backyard in CT.
It has large pinchers & a tail/stinger/? that is usually recessed, but quickly comes out when aproached. It also sticks it’s rear end up, as if a defense as well.
Lastly, we found it over a 1/2” diameter hole, which it appeared to be protecting.
This is a female Broad-Necked Root Borer, Prionus laticollis, and what you describe as a stinger is actually her harmless ovipositor that she uses to lay eggs.
Letter 6 – Broad Necked Root Borer
Subject: Huge black beetle
Location: New York, US
July 9, 2014 9:25 am
While hiking along a trail in Harriman State Park, New York, I came across this monster. It was about 2-3 inches long, and holding its rear end up in the air. It also looked extremely swollen. Any ideas as to what it could be?
July is the month we get the most sightings and requests for the identifications of Longicorns in the subfamily Prioninae, and your Prionid is a Broad-Necked Root Borer, Prionus laticollis.
Letter 7 – Broad-Necked Root Borer
Subject: Broad Necked Root Borer?
Location: Doylestown, PA
July 16, 2014 8:07 am
Hello! Love your site!
My co-worker and I found this beetle on one of Heritage Conservancy’s preserved properties in Doylestown, PA! It totally caught me be surprise as I’ve never seen a beetle so large.
It was located in a garden bed under some maple trees – a large, very shaded, and mulched bed with some skip laurel and other shrubs scattered around. After a little photo session, we returned it back to where we found it.
It has mandibles but the coloring looks similar to the female photos you have featured here, so i’m trying to confirm species as well as male or female. If it’s a male – I can’t imagine what the female must look like!
Thank you so much for any info and keep up the good work!
Signature: Erin H
Letter 8 – Broad Necked Root Borer
Location: Southeast Pennsylvania
July 2, 2015 3:35 pm
We found a few of these In our yard. They seemed to come right out of a hole in the ground. It looks like a beetle but we’ve never seen one this big. It’s about 1.5-2 inche’s long. Thank you!
Signature: Beetle Bug Central
Letter 9 – Broad Necked Root Borer
Subject: 2 inch beetle Bug
Geographic location of the bug: Bernardsville NJ
Time: 06:33 PM EDT
Your letter to the bugman: Here’s a photo- what is it?
How you want your letter signed: Nancy
This is a female Broad Necked Root Borer, Prionus laticollis, and what appears to be a stinger is actually an ovipositor, an organ used during the egg laying process.