If you suspect that an insect you have found on or near a black walnut tree is a walnut twig beetle or that you have found damage caused by thousand cankers disease:
- Collect any suspect insect(s), both adults and larvae, if possible.
- Place them in a vial or small jar and cover it with 70 percent ethanol or plain rubbing alcohol as soon as possible after collection.
- Collect the affected branch if possible.
- Take photographs, if possible, showing the crown of the tree, partially peeled branch to show cankers and adult and larval insects.
- Call (608) 224-4745 or email Renee.Pinski@wi.gov.