Effective controls for TCD have not yet been identified and their development will require better understanding of the biology of the walnut twig beetle and the fungus. Rapid detection and removal of infected trees currently remains the primary means of managing TCD. Stopping or slowing its spread from infested areas relies on quarantines of wood products and public education.
Investigate dying/dead walnuts thoroughly and report suspected cases of TCD. You can access state specific contact information for your state through the state map.
Help minimize the chances of spreading TCD
Obtain expert assistance when collecting and sending samples for diagnosis. Samples need to be carefully handled and sent only to laboratories which are authorized to handle such specimens and have the expertise to identify these agents. If in doubt about who to call or consult, check first with your State Forestry Agency or State University Extension Service.
Prompt tree removal and proper debris disposal may help to limit the further spread of TCD; obtain proper disposal instruction from qualified experts if TCD is diagnosed. Beetles can emerge by the thousands from any dead and dying wood pieces. Chipping does not kill the beetles, but does interfere with their breeding, and often results in wood pieces still large enough to allow beetles to emerge and spread TCD. Prompt destruction by burning or burying is probably the only sure way to prevent spread from infested walnut. Be sure to check for local air quality and fire restrictions prior to burning. Covering infested wood with plastic or other material is not sufficient.
The beetles and fungus are restricted to the tree bark so consider the movement of any bark materials from dead or dying trees as the highest risk for additional disease spread.
Don’t transport dead/dying walnut wood, branches or twigs off-site.
Don’t transport walnut as firewood. Use local sources of wood when camping. More information on the risks of transporting firewood can be found at the Don’t Move Firewood website.
TCD is not federally-regulated but be aware that individual states have enacted state- or county-level quarantines restricting the movement of untreated walnut materials of all kinds. We provide information on these quarantines on this website. We strongly suggest checking with state authorities before moving, buying, or selling any walnut wood or material to ensure you have the most recent information.
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.
