Four-spined Engraver Beetle (Ips avulsus) - Ips beetles are cylindrical, black to reddish brown in color, and vary in size from 3/32” to ¼” in length. Despite their small size, they can be identified by a scooped out rear end surrounded by spines. Immature adults, found under the bark, are usually yellowish to light brown. Fully-grown larvae and pupae are yellowish white and vary from 3/32” to 3/16” in length. Eggs are very small and white. All life stages (eggs, larvae, pupae, and adults) occur under the bark. They do not bore into the wood.