Blog Post Image: Slippery bark protects trees from pine beetle attack, according to CU-Boulder study

Clockwise from top left: (1) Two lodgepole pines growing side-by-side with notably different bark textures, (2) a rough-barked limber pine that has been attacked by bark beetles, (3) a limber pine that has both rough and smooth bark, with pine beetle attacks only on the rough bark, (4) a limber pine with predominantly smooth bark. Photo courtesy of Scott Ferrenberg.