What Do Longhorn Beetles Eat? (You Will Be Surprised To Know)

Longhorn beetles can hollow out an entire tree! While the adults feed on nectar, the larvae are the ones who cause the real damage to trees. Let us find out more.

Long-horned or Longicorn beetles have an unusual eating pattern. The eating habits of these beetles can harm trees and are a significant cause of damage to hardwood forests.

Belonging to the Cerambycidae family of the Coleoptera Order, these Arthropods have over 35,000 species.

Despite their names, longhorn beetles do not have long horns. It is their distinctively large pair of antennae that gives them the look for which they are named.

Do Longhorn Beetles Eat? #1 Answer

What Do They Eat?

Longhorn beetles are herbivores and steer clear of insects and meat. They spend their lives living in trees and get all their nutrition from those very trees.

While most longhorned beetles chew on dead wood, there is one species – the Asian Long-horned beetle (Anoplophora Glabripennis) that has become a menace to hardwood trees in North America.

The adult beetles of this species have a particular affinity towards hardwood trees like maple, birch, willow, elm, poplar, ash, and many more.

They lay their eggs inside the tree barks of these trees. When the larvae come out, the hardwood around them becomes one of their favorite snacks.

Some of the other common things that longhorn beetles love to eat are stems of smaller plants, twigs, leaves, seeds, nectars, fruits, flowers, grass, fungus, etc.

Due to their ability to process dead wood and the insects that reside within it, they are often considered beneficial insects.

They thrive and flourish best amidst deep and dense forest areas with abundant plants and trees.

How Do They Eat?

The trunks and the bark are where the Asian Longhorned beetle larvae start their feeding frenzy from.

But slowly, they make their way inside and, over time, can reach the very core of the tree, hollowing it out from the inside.

The beetles burrow through the trunk to chew away the plant tissue while cutting the nutrition supply route to the other parts of the tree.

They excavated multiple tunnels during this period, creating large visible holes all along the trunk.

When the adult beetles come out of these holes, they also cause the plant sap to drip out of them, making life even worse for the tree.

Do Longhorn Beetles Eat? #1 Answer

Do They Eat Other Insects?

Longhorn Beetles do not feed on any insects or other living organisms except for wood. Most species of beetles are herbivores, and longhorns are not an exception.

However, not all beetles are pure plant eaters. Some beetle species, such as the Epomis beetles, can eat other insects and amphibians.

What Liquids Do They Consume?

Like all the other species on earth, Longhorn beetles have an affinity towards water. They consider moist wood as a good source to get this water.

This is probably the reason why longhorn beetles search for wet lumber first. Most adult longhorn beetles also love to sip on nectar and tree sap for nutrition.

Damage Longhorn Beetle Cause By Eating Wood

An infestation of longhorn beetles is one of the worst things to happen to a tree. These beetles are wood-boring pests and can dig deep tunnels into their trunks while scavenging through the wood tissue.

As the beetles continue to borrow the tunnels, they often leave an exit hole on the opposite side of the trunk that measures about 1/8th to 3/8th of an inch. This hole further oozes out tree sap, making the tree even more vulnerable to attack from other pests and diseases.

These beetles cut short the nutrition supply chain from the root to the rest of the plant. By eating the tissue midway on the trunk, they can make the higher sections of the tree wither away.

As the plant tissue rapidly degrades and decomposes, the overall structural integrity of the tree is significantly compromised, which leads to its untimely death.

Do Longhorn Beetles Eat? #1 Answer

Other Insects That Eat Wood

Longhorn beetles are not the only insect interested in attacking trees. Here, we have listed six other bugs that have similar eating habits.


Present since the Jurrasic age, termites are one of the most invasive insect species on the planet.

These insects thrive in colonies with clearly defined hierarchies and structures. The worker termites, using their strong mouths, tear apart and chew cellulose from wood. They collect it for their other brethren to eat as well.

Carpenter Ants

Interestingly, even though these pests are known for eating away wood, they do not technically feed on wood.

Instead, they chew the wood from old and dead logs to build interconnecting tunnels to lay their eggs.

Carpenter Bees

The solitary bees also chew wood from barks and trunks of trees to build their nests and lay eggs.

Horntail wasps

The horntail wasps bore tunnels into the trees to live in them rather than eat the tree tissue.

Instead, these wasps thrive on the fungus that proliferates among the eggs that they lay in the burrowed holes.

Powderpost beetles

The insect is named so because of the sawdust-like powder they leave behind as they bore holes into the wood.

The starch derived from the wood is primarily used to feed the larvae and help them grow for about a year.


Recognizable due to their long and narrow distinctive snouts, weevils thrive exclusively on rotten wood predigested by fungus.

Do Longhorn Beetles Eat? #1 Answer

Frequently Asked Questions

Do longhorn beetles eat plants?

Yes, Longhorn Beetles are strictly herbivores thriving on various parts of plants like leaves, stems, twigs, flowers, barks, grass, fungus, nectars, fruits, etc.
They have an affinity towards barks of large trees like birch, ash, willow, and poplar tree, among many more. Neither the adult beetles nor the larvae eat insects.

Are longhorn beetles harmful?

Though the longhorn beetles pose no threat to humans and animals alike, they are considered one of the worst invasive pests to trees.
They can rapidly destroy large trees by boring holes in them. Hence they can be regarded as harmful pests to the environment.

Can longhorn beetles bite

Longhorn beetles can bite humans. However, their bites are not dangerous. They might cause a bit of pain, but they should subside in a few days.
Even though these beetles are better known for staying away from humans, the occasional bad encounter can happen and leave you hurting.

Can longhorn beetles fly?

The Asian longhorn beetles can fly long distances of up to 8.5 miles when they are strong and well-fed. On average, these insects cover 1.4 miles.
Flying is one of the ways through which these insects can spread all over forests very quickly. That is why when an infestation is discovered, the best route is to completely remove entire trees from the area to protect the nearby trees and forests.

Wrap Up

Longhorn beetle Infested trees can die at a rapid pace.

The best solution to handling longhorn beetles is nothing but uprooting the trees they infest and not letting them spread. Since these bugs have no natural enemies here in the states, as of now, this is the only solution to stop them.

Hence, it is important for everyone to be vigilant and not let these insects impact our hardwood industry by reaching our hardwood forests.

Thank you for reading!


  • 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.

22 thoughts on “What Do Longhorn Beetles Eat? (You Will Be Surprised To Know)”

    • Thanks Cesar,
      I posted really quickly yesterday because I had to leave extra early for work and I didn’t have time to research, but it was such a lovely image.

  1. I just found one of these in my south Florida home but it was a decent 2+ inch and when I put a cup over it,it began hissing at me it sounded like pressure being released from a small cylinder like it was spraying. That noise coupled with the nail in the wall I thought this thing was super mutant and mounting deep in my wall. Has anyone heard of this creature hissing or know a variant that does his and is 2x normal size

    • The hissing sound you describe is known as stridulation, and many Beetles, including Scarabs and Longhorns, are capable of stridulation.

  2. Hi guys, I live in the south of Chile and have found grubs that look just like this eating the inside of my two Blackcurrant bushes. They even have the same bright yellow coloring. I have removed and destroyed the bushes, but have two of these guys in a jar to take pictures.

    • Bycids have strong mandibles and they might bite, and the bite might hurt, but Bycids are not dangerous to humans.


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