Standing trees, or logs with bark intact, affected with thousand cankers disease (TCD) can support development of tremendous numbers of walnut twig beetles. As long as live beetles remain associated with this wood it remains extremely infectious and can easily allow the disease to spread.
It is extremely important that walnut wood is never moved from areas where TCD has been detected. Due to the high value of black walnut for woodworking purposes, the movement of walnut wood is a serious concern. Milled wood without bark and logs without bark that have been dried for three years or more likely will not be a source of risk.
Moving walnut from non-quarantined areas is risky as pest infestations can take years before being recognized. Trees can be harvested and shipped after they are infected, but before becoming symptomatic or a quarantine is announced. It is strongly recommended that all walnut wood be milled and used locally to prevent accidental spread of walnut twig beetles that can move the disease into new areas.
More information on the risks of moving wood can be found at the Don't Move Firewood website.