Members of the order Coleoptera, beetles represent 40 percent of all insect species. Like other insects, beetles feature a pair of antennae, three pairs of legs, and a rigid exoskeleton. However, beetles also have a pair of hard wings, which are called elytra. Washington is home to many species of beetles, including bark, darkling, click, carrion, tiger, blister, longhorn, dung and scarab beetles.
Bark, Darkling and Click Beetles
Bark beetles are members or the subfamily Scolytinae, and are common pests that attack pine trees. A common species found in Washington is the mountain pine beetle (Dendroctonus ponderosae). Darkling or darkening beetles found in Washington include members of the genus Eleodes, which developed several adaptations, including fused wing covers, which helps to retain water, but restrict their flying. They are nocturnal animals and, like most beetles, feed on decaying plant material. Part of the family Elateridae, click beetles have the ability to make a clicking sound and flick their bodies into the air when feeling threatened. The western eyed click beetle (Alaus melanops) is found in Washington.
Carrion and Tiger Beetles
Carrion beetles are part of the family Silphidae, a group that like to feed on animals' carcasses. More than 40 species are found in North America, some of which live in Washington, such as the northern carrion beetle (Thanatophilus lapponicus). Known for their aggressive behavior, tiger beetles are also found in Washington, including the oblique tiger beetle (Cicindela tranquebarica).
Blister and Longhorn Beetles
Part of the family Meloidae, blister beetles can spray a skin-blistering substance called cantharidin to defend themselves. Orange-colored members of the genus Nemognatha are found in Washington. Several species of longhorn beetles (family Cerambycidae) are also found in the state, including the white spotted sawyer beetle (Monochamus scutellatus), the California prionus beetle (Prionus californicus), the ponderous borer beetle (Ergates spiculatus) and the colorful red milkweed beetle (Tetraopes tetrophthalmus).
Dung and Scarab Beetles
Dung beetles feed on feces; many species have the habit of making and rolling balls of feces for later consumption. A common species found in Washington is the tumblebug dung beetle. Closely related to dung beetles, scarab beetles are a large family, including Washington species ant scarab beetle (Cremastocheilus crinitus), the little bear beetle (Paracotalpa granicollis) and the long-haired June beetle (Polyphylla crinita).
- Bentler: Eastern Washington Beetles
- "Biological Control in the Western United States"; James Nechols; 1995
- School of Forest Resources at the University of Washington: Developing Stand Density Thresholds to Address Mountain Pine Beetle Susceptibility in Eastern Washington Forests; Elaine E. Oneil; 2006