These beetles overwinter as larvae under the bark and develop into adults in the spring, emerging with the fungus on their bodies, after the leaves fully develop. Adults then feed on limb crotches of healthy elms, infecting the tree with Dutch Elm Disease, and then fly to other elms for mating. The trees that are most vulnerable have usually been weakened by drought, disease, or other stress factors. After boring through the bark, the beetles excavate their egg galleries, grooving the inner bark and wood surface in the process. When larvae are full grown, they construct pupa cells at the end of their larval mines.
New adults emerge by boring directly through the bark, leaving tiny holes in the bark.
The female elm bark beetles lay their eggs beneath the bark of dead or dying elm trees. The larvae mature underneath the bark, pupate, and emerge as adults at the base of the elm tree. If the elm tree is infected with Dutch Elm Disease, the newly hatched beetles will emerge from the tree carrying the fungus Ophiostoma ulmi on their bodies. The beetles then fly to healthy elm trees to feed and breed in the two to four year old branches. The fungus can also be spread at this time.