The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), in partnership with the Wisconsin DNR, has detected emerald ash borer in four new counties (Dunn, Oconto, Pepin and Shawano). Please read this DATCP article for more information.
Adult emerald ash borer beetle.
If you are a landowner and have questions about ash trees in your woodlot, contact your local DNR forester using the Forestry Assistance Locator.
By Bill McNee, forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942
The summer of 2020 saw a major rebound of the gypsy moth population after several years of weather conditions that were unfavorable for the non-native, defoliating pest. A mild winter and average summer temperatures/precipitation during the caterpillar stage were all favorable for a population increase.
Female moth laying eggs on tree trunk.
Continue reading “Gypsy moth populations rebound in 2020 – look for egg masses this fall”
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
If you’ve ever looked closely at oak leaves in late summer you know that you can find lots of interesting things on them this time of year. You’ll see anything from a variety of caterpillars and galls of all shapes and sizes to dead portions of branches caused by insects and diseases. These late season defoliators rarely cause actual health issues for the tree, and rarely require any control, but they can be very noticeable with some dramatic damage. Continue reading “Oak webworms, blotchminers, skeletonizers and dead branch tips in late summer”
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Spruce budworm defoliation was severe in many areas of northern Wisconsin this year. New needles on balsam fir and spruce were eaten, although in most areas the balsam fir had greater amounts of defoliation than the spruce. Feeding by this native caterpillar for several years in a row can cause trees to start to decline and even die, which is occurring in a number of areas of northern Wisconsin.
Mortality of balsam fir due to repeated defoliation by spruce budworm. Green trees in this photo, including hardwoods and pines, are not fed upon by spruce budworm.
Continue reading “Spruce budworm and balsam fir mortality in northern Wisconsin”
If you’ve noticed large yellow wasps flying around this summer, you may be wondering whether you’ve seen the Asian giant hornet (aka “murder hornet”). This probably gave you some pause considering all the headlines they received earlier this year, but fortunately for Wisconsin and much of the Midwest, murder hornets have not yet been found in the region.
The cicada killer is a common native insect in the Midwest.
By Elly Voigt, forest health lab assistant, Fitchburg
Beech leaf disease (BLD) is a relatively recently discovered, destructive disease of beech trees in the US. It was first observed in 2012 in Ohio and has since spread to areas of Pennsylvania, New York, Connecticut, Rhode Island, Massachusetts and Ontario, Canada. BLD affects our native beech species, American beech (Fagus grandifolia) and ornamental beech species, including European beech (Fagus sylvatica). The disease has not yet been observed in Wisconsin but could become an issue in the future.
Symptomatic leaf puckering of a beech tree with BLD. Credit: Ohio State University.
The HRD stump treatment guidelines are now available in an interactive format to make it easier to obtain stand-specific recommendations. You can find the link called “Interactive guidelines” on the right side bar under “Additional Resources” at the DNR HRD webpage. The user will be asked a series of questions and then a stand-specific recommendation will be provided at the end. The interactive guidelines incorporate Exceptions and Modifications described in the guidelines. Check it out!
Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
In early June we started getting reports of balsam fir trees rapidly changing from green to rusty red and dying in just a matter of weeks. Reports and observations are still coming in at the time of this writing, so this article gives a brief synopsis of what we’ve seen so far this year. Symptoms have been observed in some northern and central counties.
Some balsam fir crowns died rapidly this spring for reasons still being explored.
You can help keep native elm trees in the forests of Wisconsin! The US Forest Service continues to work on a project to identify Dutch elm disease (DED)-tolerant American elms native to Wisconsin forests. The goal of the project is to identify and propagate survivor American elms, especially from the colder hardiness zones 3-4, and develop a series of clone banks. Selections would eventually be screened for tolerance to DED. Ultimately, the goal is to make DED-tolerant American elm available for reforestation in northern areas, particularly as a component on sites currently forested by black ash.
If you live in hardiness zones 3 and 4, please look for evidence of surviving elms and report them to the US Forest Service.
By Bill McNee, forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942
The Division of Forestry has completed a revision of the emerald ash borer silviculture guidelines to help foresters prepare for and respond to the arrival of emerald ash borer (EAB) in a forest stand.
Continue reading “Updated emerald ash borer silviculture guidelines now available”
