Longhorn Beetles (Cerambycidae) — identification, habitat & look-alikes

Longhorn beetles are often recognized by antennae as long as the body, but the family contains many shorter-horned exceptions. Most spend far more time hidden as larvae in wood or plant stems than they do as visible adults on bark, leaves, or flowers.

In this group

linden borerSaperda vestita

An eastern North American species whose larvae develop in linden and basswood trees. Look near those trees for adults.

eastern elderberry borerDesmocerus palliatus

An eastern species that uses elderberry; adults have dark blue wing covers with a yellow-orange band across their front ends.

white-spotted sawyerMonochamus scutellatus

A widespread native of conifer forests; the pale spot between the wing covers helps separate it from Asian longhorned beetle.

locust borerMegacyllene robiniae

Common in the East on goldenrod in late summer and fall; black-and-yellow markings make it look wasplike.

Asian longhorned beetleAnoplophora glabripennis

An invasive beetle in U.S. quarantine areas, with a shiny black body, irregular white spots, and black-and-white antennae.

Appearance

How to recognize it: Adults are usually elongated, cylindrical beetles with antennae at least half as long as the body, and often much longer. The compound eyes commonly curve around the base of each antenna, but color and body shape vary widely.

Look-alikes

metallic wood-boring beetlesBuprestidae

Metallic wood-boring beetles often look flatter and more bullet-shaped, with shorter antennae. Many longhorn beetles have a longer, more cylindrical body and long antennae, though there are exceptions.

Why they get mixed upBoth families include elongated beetles whose larvae tunnel in wood.

Where it lives

Typical habitats: forests
woodlands
parks and yards
flower patches
dead wood
Range: Longhorn beetles occur throughout the United States, with different species in eastern woodlands, western forests, and other habitats.
Preferred conditions: Each species is tied to particular and wood conditions. Some need living trees, while many use stressed, dying, or dead wood.

Behavior

Diet: Larvae mostly feed in woody plants, especially bark, the layer beneath it, and wood, while some develop in herbaceous stems. Adults are also mostly plant eaters, though some species barely feed.
Activity: Adults may visit flowers, bark, foliage, sap, fruit, or fungi, and some barely feed. Depending on the species, they may be active by day or night.
Overwintering: In temperate regions, species may overwinter as larvae or at other stages. The time from egg to adult varies widely among species.

Life cycle

Reproduction: Females usually place eggs on or under the bark of a larval host plant. Larvae tunnel under bark or through wood, then in the plant or sometimes in soil before adults emerge.
Caterpillar food plants: Most species develop in trees, shrubs, or woody vines, but some use herb stems, bamboo, cacti, palms, or roots. Host range differs greatly by species.

Name and classification

Group name: Their larvae are commonly called roundheaded borers, especially in forestry.
Number of species: More than 36,000 longhorn beetle species are known worldwide.

Conservation

Threats: Species that depend on old trees and dead wood can decline when those habitats are removed.

26 sources