Broad Neck Root Borer: A Threat To Your Garden

Maryland Biodiversity Project Broadnecked Root Borer (Prionus
Maryland Biodiversity Project Broadnecked Root Borer (Prionus from


Gardening enthusiasts beware! There is a new pest in town that is wreaking havoc on gardens across the country. Meet the broad neck root borer, a notorious insect that is causing significant damage to plants and trees. In this article, we will explore the characteristics of this destructive pest and provide you with essential tips on how to protect your garden.

What is a Broad Neck Root Borer?

The broad neck root borer, scientifically known as Prionus laticollis, is a large beetle that belongs to the longhorn beetle family. It is native to North America and primarily found in the eastern and central regions of the United States. This formidable insect can grow up to two inches in length and has a distinct broad neck, which gives it its common name.

Identification and Lifecycle

The adult broad neck root borers are dark brown or black in color with long antennae. They are most active during the summer months when they emerge from the ground to mate and lay eggs. The female beetles lay their eggs near the base of host plants, such as fruit trees, ornamental shrubs, and hardwood trees.

Once the eggs hatch, the larvae burrow into the roots of the host plant and feed on the sapwood and cambium layer. This feeding activity weakens the plant’s root system, leading to stunted growth, yellowing leaves, and eventual death if left untreated.

Signs of Infestation

Identifying a broad neck root borer infestation can be challenging, as the larvae remain hidden beneath the soil. However, there are some telltale signs to watch out for. Look for wilting or yellowing leaves, excessive dieback of branches, and sawdust-like frass near the base of the affected plants.

Preventing Infestation

Prevention is key when it comes to dealing with broad neck root borers. Here are some effective preventive measures:

1. Keep your garden clean and free from decaying plant matter, as these pests are attracted to rotting wood.

2. Avoid overwatering your plants, as damp soil can attract broad neck root borers.

3. Apply a layer of organic mulch around the base of your plants to deter the beetles from laying their eggs.

4. Regularly inspect your plants for any signs of infestation and take immediate action if detected.

Controlling Broad Neck Root Borers

If your garden is already infested with broad neck root borers, it is crucial to take prompt action to minimize damage. Here are some effective control methods:

1. Mechanical Control: Handpicking the adult beetles can help reduce their population. However, this method may not be practical for large infestations.

2. Biological Control: Introducing natural predators, such as parasitic wasps, can help control the broad neck root borer population.

3. Chemical Control: In severe cases, insecticides labeled for borers can be used. However, it is essential to follow the instructions carefully and use them sparingly to minimize environmental impact.


The broad neck root borer is a formidable pest that can cause extensive damage to your garden. By implementing preventive measures and taking prompt action if infestation occurs, you can protect your plants and ensure a thriving garden for years to come. Stay vigilant, and may your garden remain free from the grasp of this destructive insect!