Minnesota Seasons - Metallic Wood-boring Beetles (Agrilus spp.)

Overview • Description • Distribution • Taxonomy

metallic wood-boring beetle (Agrilus sp.) — Photo by Alfredo Colon

Overview

Agrilus is a very large, exceptionally diverse genus of beetles known as metallic wood-boring beetles or jewel beetles. There almost 3,000 currently recognized species in about 40 subgenera worldwide, more than any other genus in the animal kingdom. There are 174 species in 2 subgenera North America north of Mexico, and at least 31 species in Minnesota. They occur on every continent except Greenland and Antarctica.

They are found on hardwood broad-leaved plants. Larvae are wood borers. They create tunnels beneath the bark and are rarely seen. Adults feed on the leaves of the same species that host the larvae.

The most well known member is the emerald ash borer (Agrilus planipennis), which is responsible for the deaths of tens of millions of ash trees in North America. The most destructive member is the two-lined chestnut borer (Agrilus bilineatus). It attacks oaks, beech, ironwood, and chestnut trees.

Description

Agrilus adults are ⅛″ to 9⁄16″ (3.0 to 14.5 mm) long. The body is rigid, bullet-shaped, narrow, and long. The upper (dorsal) side is frequently metallic and usually shiny. The under (ventral) side is nearly always iridescent. Some species have yellow or yellowish spots, one species has yellow stripes.

The antennae are short and sawtoothed. They have 11 segments.

The forewings (elytra) have nearly parallel sides and often taper to a point at the rear.

The last part of the leg (tarsus), corresponding to the foot, has 5 segments.

Distribution

Distribution Map

Sources

24, 27, 29, 30, 82, 83.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu, 10/24/2025).

10/24/2025

Taxonomy

Order

Coleoptera (beetles)

Suborder

Polyphaga (water, rove, scarab, long-horned, leaf, and snout beetles)

Infraorder

Elateriformia

Superfamily

Buprestoidea

Family

Buprestidae (jewel beetles)

Subfamily

Agrilinae

Tribe

Agrilini

Subtribe

Agrilina

Subordinate Taxa

The genus Agrilus is a very large group of jewel beetles. Attempts to classify it into subgenera exist, but these are often based on regional groupings of species rather than a universally agreed-upon system. These divisions are often regional and not universally accepted.

alder borer (Agrilus pensus)