Authored by Minnesota Department of Agriculture, Plant Protection Division, August 2009
Reviewed by Minnesota EAB Science Advisory Group, September 2009
EAB infestations are difficult to identify in the early stages of the infestation. EAB infestation areas grow in diameter via the natural spread of the insect and through non-connected satellite infestations which are created by both artificial and natural dispersion. For these reasons, when new EAB infestations are discovered, quarantines are enacted on a large scale (county or greater) with the assumption that the infestation is spread beyond what is observed – both in terms of the size of individual pockets of infestation and the distribution of those pockets over an area. However, while the quarantine necessarily covers a large area where EAB may be present, the distribution of EAB is likely not uniform throughout the quarantine.
For this reason, areas called “Known EAB-Infested Areas” have been designated. Known EAB-Infested Areas are areas where trees infested with EAB have been documented. Ash trees or parts of ash trees removed from these areas have a high probability of being infested with EAB. This is true for trees that appear healthy as well as those that have multiple symptoms of EAB infestation. For this reason, special precautions are advised for working with ash within these areas. These guidelines should be followed 100 percent of the time when working within Known EAB-Infested Areas. Also following these guidelines when working elsewhere within the EAB quarantine will provide the lowest degree of risk for movement of EAB.
*Active vs. Dormant Period
Branch / Tree / Stump removal should be avoided during the EAB Active Period for two reasons:
1) By postponing pruning until the fall, you can help reduce the risk of EAB spreading. If the tree is left intact during the EAB Active Period, it can provide habitat for EAB adults to lay eggs. But since the adults won’t emerge until the following year, if this tree or branch is cut and properly disposed of during the EAB Dormant Period, any EAB that may exist in the ash material will be destroyed when the wood is destroyed.
2) Material moved during the EAB Active Period may release adults at any time during transportation into a previously un-infested area.
**Disposal of outer 1” of bark/wood vs. whole tree
Only the outer 1” of bark/wood harbors EAB. If this material is removed, the remaining wood may be utilized as desired and does not need to be destroyed.
Options for effectively treating the material include grinding to a small diameter (less than one inch in two dimensions), burning or burying.