The professionally-designed version of the Heterobasidion root disease (HRD) stump treatment guidelines is now posted on the DNR’s HRD webpage. The revised stump treatment guidelines, developed to reduce the risk of introduction and spread of HRD in Wisconsin, were implemented January 1, 2019. The content is the same as the guidelines that were approved last year, but this document has a layout that is much more user-friendly. Explore the new look of the HRD guidelines.
Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Trees in the red oak group (those with points on their leaves) that were infected with the oak wilt fungus this spring will rapidly drop their leaves from July to September and be dead by fall. This wilting and dropping of the green leaves happens quickly. Once it starts, the tree will drop most of its leaves within just a few weeks.
Tree dying from oak wilt with rapidly dropping leaves. The tree was injured in May, attracting the beetles that help spread the fungus, and the tree was dead by the end of the year. Photo was taken in August.
Red oak leaf from infected tree. Leaves are often green at the base, with the outer portions of the leaf appearing water-soaked or brownish.
Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Ants, aphids, and sooty mold can cause stunting and death of young white pines, but fortunately there are some steps you can take to protect your trees from these pests.
Ants (upper right) guard aphids from predators as they feed. In exchange, the ants collect the sweet honeydew excreted by the aphids.
Continue reading “Ants, aphids and sooty mold on white pine”
Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690
Cherry scallop shell moth, a native defoliator, is back again in Jefferson and Walworth counties. Several residents recently reported large numbers of moths in areas that have experienced multiple years of defoliation by this insect.
Eggs laid by those moths are expected to hatch soon, and the emerging caterpillars will begin feeding on cherry tree foliage. Hopefully, populations of egg-parasitizing natural enemies will be high enough this year to provide relief to stressed trees.
Early instar caterpillars on cherry leaf.
Continue reading “Watch for cherry scallop shell moth defoliation”
Todd Lanigan, forest health specialist, Eau Claire, Todd.Lanigan@wisconsin.gov, 715-839-1632
You may have noticed some of the elms and maples had a lot of brown in them at the end of May and early June. Some elms and maples produced a lot of seed this spring, which reduced the amount of energy available for producing leaves. With fewer leaves and more of the brown, papery seeds, the trees can take on a thin, brown appearance.
Heavy seed years can occur for many reasons. It happens naturally from time to time and it can also be stimulated by environmental stressors. A couple of examples of environmental stressors are: excessive moisture, winter injury and frost damage to roots.
The cause of this year’s heavy seed production is anyone’s guess. There does not appear to be a common pattern between the affected trees to indicate whether it was simply a normal heavy seed year or related to an environmental factor.
Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Defoliation from larch casebearer (Coleophora laricella) is showing up in some areas of northeast and northcentral Wisconsin. The defoliation is patchy and of moderate intensity, resulting in trees with various degrees of browning due to the insect’s feeding habits. Some appear pale yellow or brown throughout the crown while others only have partial browning.
Defoliation by larch casebearer will cause needles to turn yellow then brown. Trees will usually send out more needles and be green again by mid-summer.
Paul Cigan, forest health specialist, Hayward, Paul.Cigan@wisconsin.gov, 715-416-4920
Jack pine shoots are flagging over a large area of northern and west central Wisconsin this summer due to feeding injury from the jack pine resin midge. Symptoms include scattered dead branch tips and pitch masses on terminal buds and on twigs where larvae feed.
Jack pine with dead branch tips. Photo: Paul Cigan.
Continue reading “Branch flagging caused by jack pine resin midge”
Forestry officials suggest caution with fireworks
By: Amy Luebke, DNR
Each year the use of both legal and illegal fireworks causes wildfires in Wisconsin. Anyone using legal fireworks should do so only in a clear area away from buildings, vehicles and shrubbery and should have water or a fire extinguisher handy. Remember that wildfires can occur anytime the ground is not snow covered. Make sure you are aware of your local weather conditions and plan accordingly. Fireworks can cause wildfires. Don’t let your fun turn into flames!
WAA Summer Conference
Join the WAA (Wisconsin Arborist Association) for their summer conference and picnic at the Green Lake Conference Center in Green Lake on Tuesday, July 16th. The program committee has put together another excellent lineup for this event. They are offering two educational tracks, one indoors and one outdoors- a little something for everyone.
Topics include:
For more information or to register, visit the WAA website at http://www.waa-isa.org/events-programs/summer-conference/.
Invasive plants have been shown to impact Wisconsin’s economy, environment and human health. Roadsides are a key area where these unwanted plants establish and spread. These right of way habitats are challenging to work in but focused efforts can be successful in preventing spread and reduce invasive plant populations.
To help educate and jumpstart management, The University of Wisconsin-Madison Extension along with 4-Control are conducting roadside invasive plant workshops throughout the state. We invite you to attend one of these five regional workshops. While this training is available to anyone interested, the focus will be on training staff of municipalities that manage vegetation on roadsides. Continue reading “Invasive plant management on roadsides workshops”
