Long Horned Beetle

Longhorn beetles, also called long-horned beetles or longicorns, are beetles famous for their extremely long antennae, which are often as long as their bodies or even longer. They belong to the family Cerambycidae, which has more than 30,000 known species living on every continent except Antarctica. Their larvae bore into wood, which is why they are sometimes called round-headed borers.

Longhorn beetle Quick Facts

Common name	Longhorn beetle
Scientific name	Cerambycidae
Kingdom	Animalia
Phylum	Arthropoda
Class	Insecta
Order	Coleoptera
Type	Insect (beetle family)
Diet	Larvae eat wood; adults eat pollen, nectar, bark, leaves or sap
Habitat	Forests, woodlands, gardens and anywhere trees grow
Native range	Worldwide, except Antarctica
Size	From a few mm to about 16 cm (titan beetle)
Lifespan	Usually 1-3 years, mostly spent as a larva
Special feature	Antennae often as long as the body or longer

What Do Longhorn Beetles Look Like?

Longhorn beetles come in an amazing range of sizes and colors. Most have a long, fairly narrow body and, of course, long antennae. In many species the male’s antennae are much longer than the female’s. Some longhorns are dull brown or black, while others are brightly patterned with stripes, spots or bands, and a few even look like wasps.

Sizes range from just a few millimeters to giants. The South American titan beetle (Titanus giganteus) can grow to about 16 cm (over 6 inches) long, making it one of the largest insects in the world.

A well-known example is the Asian longhorned beetle (Anoplophora glabripennis). It is about 2.5 to 4 cm (1 to 1.5 inches) long, glossy black with white spots on its wing covers, and has black-and-white banded antennae that can be up to two and a half times its body length. Its feet often have a bluish tint.

Main Groups of Longhorn Beetles

Scientists divide the longhorn family into several subfamilies. Some of the best known are:

• Cerambycinae: a very large and varied group with thousands of species, many of them colorful. Many live in the tropics of the Americas.
• Lamiinae (flat-faced longhorns): the largest subfamily, with a flat, nearly vertical face. The Asian longhorned beetle and pine sawyers belong here.
• Lepturinae (flower longhorns): often found on flowers, feeding on pollen. They are most varied in the Northern Hemisphere.
• Prioninae: large, usually brown or black beetles that are mostly active at night and often fly to lights. Males of some species have big jaws used in fights.
• Necydalinae: a small group with very short wing covers that leave the wings exposed. Many look like wasps, and their short wing covers make them look a little like rove beetles.
• Parandrinae: a small group with unusually short antennae. They look rather like small stag beetles.
• Spondylidinae: a small group, many of which live in conifer forests of the north.

Life Cycle

Longhorn beetles go through complete metamorphosis: egg, larva, pupa and adult.

After mating, the female chews small pits or slits in bark and lays her eggs inside, usually one egg per pit. The eggs hatch in about one to two weeks. The pale, legless or nearly legless larvae have a rounded, slightly wider front end. They tunnel first under the bark, feeding on the soft living layers, and later bore deeper into the wood. Fleshy pads on their body segments help them grip the tunnel walls as they move.

As they eat, the larvae push out sawdust-like waste called frass. The larval stage is the longest part of their life and usually lasts one to three years, sometimes much longer in dry, old wood. Larvae often rest through the winter. When ready, they make a chamber near the surface of the wood and pupate. The new adult then chews its way out, leaving a round or oval exit hole.

Adults usually live for a few weeks to a few months. Females of some species need to feed for a while before they can lay eggs. Males use their long antennae to pick up the scent (pheromones) of females.

What Do Longhorn Beetles Eat?

Almost all longhorn larvae eat wood or other plant tissue. Many feed on dead or dying trees, while some attack healthy living trees. Adults have varied diets: some feed on pollen and nectar from flowers, others chew bark, twigs, leaves, sap or fruit, and some hardly feed at all.

Why Longhorn Beetles Matter

Longhorn beetles play an important role in nature. By tunneling into dead and dying wood, their larvae help break it down and return nutrients to the soil. Many birds, especially woodpeckers, rely on them for food.

However, a few species are serious pests. The Asian longhorned beetle, which is native to China and Korea, has been accidentally carried to North America and Europe in wooden packing material. It attacks healthy hardwood trees such as maples, and has killed huge numbers of trees in China. Where it has been introduced, officials work to wipe it out by inspecting trees and removing infested ones. Some other longhorns damage timber or wooden furniture.

How You Can Help

• Do not move firewood long distances. Buy or gather it near where you will burn it, as hidden larvae can hitch a ride.
• Learn to recognize invasive species like the Asian longhorned beetle, and report sightings to your local forestry or agriculture agency.
• Leave some dead wood in gardens and woodlands where safe, to support native beetles and the animals that eat them.

Longhorn beetle FAQs