The Banded Alder Borer Beetle is a member of the Longhorn Beetle family Cerambycidae. Their antennae are quite long, sometimes three times longer than the body of the beetle. These data-gathering tools tend to sweep back and forth, behind and in front of the insect. There are over 1,200 species of Longhorn Beetle on the continent.
The head of the Banded Alder Borer is black, but its prothorax (shoulders) is white with a dark spot in the center of it. The elytra (wing covering) has alternating thick bands of black and white along the rest of the body. The antennae of this species are also banded in black and white.
Though they are visually easy to recognize, more research can be done to learn more about the life cycle of this beetle. Strangely, adult beetles are attracted to the smell of drying paint. It is believed that the odor the paint emits might be similar to pheromones that the beetles make themselves and they are drawn to the paint unwittingly. Another suggestion is that the paint mimics the smell of dying trees, which this beetle finds attractive.
Adults are active in the day and can be found in large numbers. The seem to prefer a particular type of tree based on their geographical position. In the Southwest, they cluster on alder trees, but they are seen on willows in the Rocky Mountains and ash trees in the Pacific Northwest. Whichever area they are in, adults all seem to deposit their eggs on the outside of the bark of the distressed or fallen tree. The larvae hatch and then bore into dead tree trunk. This beetle may be a bit of a nuisance to the logging industry. Freshly chopped-down trees are potential landing sites for eggs deposits, and once the larvae bore into the inner trunk, the wood may become less useful to people.
Common name: Banded Alder Borer Beetle
Scientific Name: Rosalia funebris
Other Names: California Laurel Borer
Adult Size (Length): 23mm to 40mm (0.91in to 1.57in) COMPARE
Identifying Colors: black; white; gray
General Description: banded, antennae, spot, flying
North American Reach (Though Not Limited To*): Alaska, Arizona, California, Idaho, Montana, Nevada, New Mexico, Oregon, Washington, Yukon Territory, British Columbia
* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.