Hickory Borer: Essential Tips for Garden Pest Control

The Hickory Borer, scientifically known as Agrilus torquatus, is a type of beetle that infests and damages hickory trees. These beetles can be easily identified by their distinctive appearance, with females being elongate and shiny brownish-copper, while males are slimmer and boast a reddish-copper pronotum with iridescent black wings. They’re typically active during spring and summer, contributing to the decline of hickory trees.

Damage caused by Hickory Borers is often evident through visible signs on the infested trees. Some noticeable indicators include tiny, flat, disk-like eggs laid under the bark, holes in the bark, and reddish frass found in bark crevices or surrounding the base of the tree. To prevent further spread and destruction, it’s crucial for tree owners and enthusiasts to be aware of the Hickory Borer’s presence and take necessary action.

In comparison to other borer insects, such as the Old House Borer and the devastating Emerald Ash Borer, the Hickory Borer poses a specific threat to hickory trees. By understanding its characteristics and learning how to manage infestations, individuals can better protect their trees and surrounding environments from these pests.

Understanding Hickory Borers

Classification and Identification

Hickory Borers belong to the family Cerambycidae, which includes longhorn beetles. Among them are the Painted Hickory Borer (Megacyllene caryae) and the Locust Borer. These beetles fall under the kingdom Animalia, phylum Arthropoda, subphylum Hexapoda, class Insecta, order Coleoptera, suborder Polyphaga, and superfamily Chrysomeloidea1.

Identifying features of Hickory Borers include:

  • Elongated, cylindrical bodies
  • Long antennae
  • Colorful patterns (e.g., black and white for the Painted Hickory Borer)

Life Cycle and Biology

The life cycle of Hickory Borers involves four stages: egg, larva, pupa, and adult2. Female beetles lay their eggs in the bark of hickory trees. Once the eggs hatch, the larvae tunnel into the wood, feeding on it and creating galleries within the wood^[3^].

Key aspects of the life cycle include:

  • Eggs: laid under bark scales
  • Larvae: feed on tree wood, creating tunnels
  • Pupae: transform into adult beetles within the wood
  • Adults: emerge from the wood and start the cycle over

Hickory Borers, along with moths and other wood-borers, can cause damage to trees, weakening their structural integrity and affecting their overall health. It is essential to monitor and control these pests to protect valuable hickory trees and the ecosystem they belong to.

Comparison of Hickory Borer and Locust Borer:

Feature Hickory Borer Locust Borer
Habitat Mainly hickory trees Prefer black locust trees
Color Black and white Black and yellow
Host Impact Tunnels and feeds on wood Tunnels and feeds on wood

Signs of Infestation

Infested Trees and Damage

Hickory borers, also known as tree borers, commonly attack Carya species, such as hickory and pecan trees. These insects typically target trees that are weak, drought-stressed, diseased, dying, or recently transplanted1. Signs of infestation include:

  • Cracked or oozing bark
  • Dead limbs
  • Girdling or encircling wounds on the tree trunk

Infestations can result in tree death if left untreated. Grubs, the larvae of borers, tunnel through the tree’s sapwood and create extensive damage2. Their egg-laying sites can also facilitate the spread of diseases and fungal infections3.

Identifying Hickory Borer Frass and Sawdust

Frass and sawdust are telltale signs of a hickory borer infestation. Frass is the waste product produced by grubs as they tunnel through the tree, while sawdust is a byproduct of their feeding4. To differentiate between healthy and infested trees, look for:

  • Reddish frass accumulating in bark crevices or around the tree base5
  • Sawdust-like material near entry holes and the surrounding area

The presence of frass and sawdust, along with the associated tree damage, are strong indicators of a hickory borer infestation.

Healthy Tree Infested Tree
Intact, smooth bark Cracked or oozing bark
Green leaves and healthy limbs Dead limbs and wilted foliage
No obvious wounds or entry holes Girdling wounds, entry holes

Remember to monitor your trees for signs of hickory borer infestation and take prompt action to manage it, protecting your trees from further harm.

Prevention and Control

Cultural and Mechanical Methods

  • Pruning: Prune and remove dead or weakened branches to reduce borer attraction.
  • Watering: Maintain proper watering practices to keep trees healthy, as borers are more attracted to stressed trees.
  • Mulching: Apply a layer of mulch around the base of the tree to conserve soil moisture and improve tree health.
  • Fertilizing: Use appropriate fertilization techniques in the spring to boost tree health and vigor.
  • Woodpecker presence: Encourage woodpeckers in the area, as they are natural predators of borers.

Chemical Control Options

  • Contact insecticides: Spray susceptible trees during the spring and early summer when adults are active for best results.
  • Systemic insecticides: Apply systemic insecticides to the soil around the tree if the infestation is severe.
Method Pros Cons
Cultural and Mechanical Methods Non-toxic, promotes overall tree health May not be sufficient against extensive infestations
Chemical Control Options Fast acting, effective against severe infestations May be toxic, can impact non-target organisms

Examples of borers include clearwing borers, flatheaded appletree borer, and metallic wood-boring beetles. These borers can infest a variety of trees such as lilac, oak, plums, and walnuts.

When it comes to choosing a method for prevention and control, consider the severity of the borer infestation, environmental impact, and the overall health of the affected tree. Integrating both cultural and mechanical methods with chemical control options can lead to a more effective management strategy against borers.

Footnotes

  1. (https://extension.okstate.edu/fact-sheets/shade-tree-borers.html) 2
  2. (https://content.ces.ncsu.edu/hickory-spiral-borer) 2
  3. (https://www.uky.edu/Ag/Entomology/treepestguide/hickory.html)
  4. Borer Insects on Trees
  5. Old House Borer

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

10 thoughts on “Hickory Borer: Essential Tips for Garden Pest Control”

  1. I found one of these banging its head into a window at home. I live in Peoria Il., is that weird? And is it supposed to buzz at you?
    And it shouldn’t be this hard to post a comment. It really shouldn’t.

    Reply
    • Hickory Borers are generally sighted in the spring and a similar looking species, the Locust Borer, is generally present in the fall when goldenrod is in bloom. A sighting in July, especially of numerous specimens, seems like it would be unusual.

      Reply
  2. I have hickory borors mating all over my twisted baby locust tree, I have never seem them here before and I am all about organic treatments and gardening. Not sure what to do? here in Colorado that is!

    Reply
  3. Hi, I was always curious what would be the name of that insect. The only time I saw this bug was in an old piece of wood that I found in a deposit. It was dead but what it caught my attention was its long antennas. I was a kid, so I thought it was a rare roach. This happened when I was living in Lima, Peru.

    Reply
  4. I don’t have an answer for killing them in the woodpile other than burning them in your wood stove, but here is how we have avoided having them running around in our house. We are only bringing in enough wood to last one week and so far have not had any adults emerge in the house. I did put one small log that had lots of large oval holes in a small sealed container with a clear top in our house on 1-22-2018. Our first adult emerged today 2-7-2018. So one week seems to be a good number as long as it’s still good and cold outside.

    Reply

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