The Town of Wake Forest has received several calls in recent days concerning the large numbers of Orangestriped Oakworms on oak trees around town, including the town’s street trees. Many residents have expressed particular concern about the caterpillar’s long-term effect on the town’s urban forest.
According to the NC Cooperative Extension Service, the Orangestriped Oakworm tends to be more of a nuisance than anything else.
It is not uncommon for this invading caterpillar to be especially abundant on oaks during this time of year. Locally, willow oak and pin oak tend to be their preferred hosts, but they occasionally feed on other hardwoods as well.
In large numbers, these ravenous feeders can quickly defoliate a tree. Fortunately, late summer defoliations are much less damaging to the health of trees than early spring defoliations.
Their greenish droppings can cover decks, vehicles and streets but they will wash away with the next rains or a good hosing.
According to the NC Cooperative Extension Service website, most trees have finished growing for the year. As a result, little permanent damage will occur to the heath of the tree. In fact, some oaks have been severely defoliated for many years in a row without obvious affect.
In the event control measures are warranted, such as to protect a small seedling oak or a high value tree, residents may opt to spray their trees by mid-August with Bacillus thuringiensis (Bt), Sevin or Orthene which are all considered effective means of control.
On large trees, a tree service with equipment to spray the entire tree may be needed.
For more information, call the NC Cooperative Extension at 919-250-1100 or visit their website at http://wake.ces.ncsu.edu/.
