South Central WI Forest Health

ALB: What to watch for in Wisconsin

By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665

We do NOT have Asian longhorned beetle (ALB) in Wisconsin at this time, but it’s good to be on the lookout for it. Every year folks submit reports of insects that they suspect to be ALB, but to date they have always been confirmed as the native whitespotted sawyer (sometimes called pine sawyer), which attacks stressed conifers rather than the maple and other hardwood species preferred by ALB. If you find a beetle that you suspect to be ALB, please collect the beetle, take some pictures, and send them to your forest health specialist, or to the University of Wisconsin Insect Diagnostic Lab for identification.

Asian longhorned beetle is a large beetle. They are smooth and shiny black with white spots and blotches on their wing covers. Photo by Joe Boggs, Ohio State University, bugwood.org

Asian longhorned beetle is a large beetle. They are smooth and shiny black with white spots and blotches on their wing covers. Photo by Joe Boggs, Ohio State University, bugwood.org.

 

Our native pine sawyer beetle appears dusty or pitted, but is often mistaken for Asian longhorned beetle. Photo by Linda Williams.

Our native pine sawyer beetle appears dusty or pitted, but is often mistaken for Asian longhorned beetle. Photo by Linda Williams.

ALB can be a very destructive pest. It is typically introduced, unintentionally, to new areas via wooden pallets, wood packing materials, or firewood. The Don’t Move Firewood website has some great tips for safe transport of firewood, how to find firewood locally, as well as a list of other invasive insects and diseases to be aware of when buying or using firewood.

USDA APHIS, which conducts eradication efforts wherever ALB is found, recently announced that an area of Ohio was officially ALB-free, and the quarantine was subsequently removed. Earlier this year in March, a separate area of Ohio was also declared ALB-free. That leaves just one area of Ohio with ALB quarantines still in effect. Eradication of ALB can take decades to complete and involves extensive efforts including tree removal and chemical treatments. States with current ALB quarantines include: Massachusetts, New York and Ohio.

For more info on ALB, check out the USDA APHIS ALB webpage, and as always, please let us know if you think you have come across a forest health concern, including ALB.

Invasive stink bug numbers increasing

By Mike Hillstrom, forest health specialist, Fitchburg. Michael.Hillstrom@wisconsin.gov; 608-513-7690

Invasive brown marmorated stink bugs (BMSB) are now well established and reproducing in southern and central Wisconsin. This fall we are getting our first reports of large numbers of BMSB gathering on the sides of houses looking for places to overwinter. This problem will continue to get worse as stink bug populations increase and their range expands. Damage to important crops, ornamental plants and trees will also be a major concern. BMSB is known to feed on a wide variety of plants including apples, tomatoes, corn, soybeans, silver maple and walnut.

Adult brown marmorated stink bugs are ½ to ¾ inch long, brown with alternating white and black patches on the edge of the abdomen and white bands on the antennae and have smooth shoulders that lack spines.

An adult brown marmorated stink bug. Photo by P.J. Liesch, University of Wisconsin Insect Diagnostic Lab.

Researchers are working on ways to manage the pesky bugs. One new method being explored is hanging black netting soaked in insecticide at locations where the bugs congregate, such as doors on the north and east sides of structures.

Samurai wasps are another promising lead. These stink bug-killing wasps found their way into the U.S. on their own over the past few years, but researchers are also working with lab-reared samurai wasps that they hope to release. Samurai wasps parasitize the eggs of BMSB but do not sting humans or other animals.

For more information about identification and management check out:
University of Wisconsin-Extension
WisContext
Midwest Stink Bug app

New forest health specialist for Central Zone

New forest health specialist Alex Feltmeyer in woods.

New forest health specialist Alex Feltmeyer. Photo by Mike Hillstrom.

Alexandra (Alex) Feltmeyer started October 15, 2018 as the Forest Health Specialist for the Central Zone (Adams, Green Lake, Lincoln, Marathon, Marquette, Menominee, Oconto, Portage, Shawano, Taylor, Waupaca, Waushara, and Wood counties). Alex will be stationed at the Plover Ranger Station and will start making connections with the foresters and partners in her zone right away. Her contact information is Alexandra.Feltmeyer@wisconsin.gov and 715-340-3810.

As a reminder, the DNR forest health specialists are available to diagnose and provide management recommendations for forest health concerns such as insect, disease and weather-related damage on forested properties in Wisconsin. The forest health specialists are also available to give presentations and trainings on current insect and disease concerns and management guidelines. For a full list of forest health program staff and the counties they cover, please visit https://dnr.wi.gov/topic/ForestHealth.

Oak leaves dropping (but not from oak wilt)

By Linda Williams, forest health specialist, Woodruff. Linda.Williams@wisconsin.gov; 920-360-0665

Heavily-spotted oak leaves began to drop in early August. Spots appeared on both the front and back of leaves. Photo: Linda Williams

Heavily-spotted oak leaves began to drop in early August. Spots appeared on both the front and back of leaves. Photo: Linda Williams

Last year, Forest Health News published an article about oaks prematurely dropping leaves although they were not infected by the fungal pathogen Ceratocystis fagacearum, the cause of oak wilt disease. Oak trees infected with oak wilt disease in springtime rapidly wilt and drop green leaves in July or August. However, oak wilt disease is not the only reason oak trees prematurely drop leaves. Continue reading “Oak leaves dropping (but not from oak wilt)”

Defoliation of black cherry trees by cherry scallop shell moth

By Mike Hillstrom, forest health specialist, Fitchburg. Michael.Hillstrom@wisconsin.gov, 608-513-7690

Caterpillars of cherry scallop shell moths (Rheumaptera prunivorata) are defoliating black cherry trees of all sizes in far southeastern Jefferson County and slightly into Walworth County. Many cherry trees have been completely defoliated. This is the third consecutive year of damage in this location. Defoliation by cherry scallop shell moth caterpillars has increased each year; hopefully natural enemies that typically cause the populations to crash show up soon and do their job as multiple years of defoliation is stressful to trees. In addition to cherry scallop shell moths, there is concern about possible attack on black cherry trees by peach bark beetles (Phloeotribus liminaris), but none have been reported yet.

Continue reading “Defoliation of black cherry trees by cherry scallop shell moth”

Defoliation by June beetles

By Mike Hillstrom, forest health specialist, Fitchburg. Michael.Hillstrom@wisconsin.gov; (608) 513-7690

June beetles defoliating an oak sapling at night.

June beetles defoliating an oak sapling at night.

June beetles (also called May beetles) are defoliating oak, aspen and birch trees in several parts of Wisconsin this spring. These beetles are unusual in that they feed on foliage at night – look for defoliation during daytime hours although no insects are present. Although the highest densities of June beetles have been found in Crawford and Grant counties in southwest Wisconsin, forest health staff has also received reports of the insect from northeast and west central Wisconsin. Continue reading “Defoliation by June beetles”

Forest health zones restructured

by Jodie Ellis, communications specialist, Forest Health team (Madison)
Jodie.Ellis@Wisconsin.gov; 608-266-2172

The number of Forest Health (FH) specialist positions in the state was recently reduced by one, going from seven fulltime positions to six. To reflect this change, the forest health zonal map was restructured to spread coverage between five forest health specialists (the FH specialist position for the Central zone, while not eliminated, remains vacant). The new assignments went into effect on April 3, 2018.

To contact a forest health specialist, please refer to the revised map below:

  • Northwest zone: Paul Cigan (Hayward), 715-416-4920, paul.cigan@wisconsin.gov
  • Northeast zone: Linda Williams (Woodruff), 715-356-5211 x232, Linda.Williams@wisconsin.gov. Also covering Lincoln, Shawano, Menominee, Waupaca and Oconto counties in the Central zone
  • West Central zone: Todd Lanigan (Eau Claire), 715-839-1632, todd.lanigan@wisconsin.gov. Also covering Taylor County in the Central zone.
  • Southeast zone: Bill McNee (Oshkosh), 920-360-0942, bill.mcnee@wisconsin.gov
  • South Central zone: Michael Hillstrom (Fitchburg, WI), 608-513-7690, michael.hillstrom@wisconsin.gov. Also covering Marathon, Wood, Portage, Adams, Waushara, Marquette and Green Lake counties in the Central zone.
  • Central zone: vacant
Restructured Forest Health zones

Restructured Forest Health zones

A fulltime FH specialist position, which had been vacant, was eliminated as part of the reduction of six positions from the Division of Forestry in the recent state budget. Because of the increased work load on the five remaining FH specialists, the FH program has permanently reduced or eliminated some of its services to customers to keep the staff’s work load at manageable levels.

Program services that have been reduced or eliminated include:

  • The DNR’s gypsy moth suppression program, which addressed population surges in areas of the state where gypsy moth is already established. This program was already in the process of being deactivated when the FH specialist position was cut. (NOTE: The Slow The Spread program, which is managed by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), remains active. It targets gypsy moth populations in the western part of the state where gypsy moth has not yet established.)
  • Site visits to confirm EAB at the township level (digital images will be used for identification instead)
  • Site visits and digital diagnostics of small acreage (less than 10 acres) for private landowners

Forest Health team members must also reduce the number of outreach presentations provided to the public.

Please contact Rebecca Gray, Forest Health team leader, with any questions at Rebecca.Gray@wisconsin.gov or by phone at 608-275-3273.

Protect oak trees from oak wilt by waiting until after July to prune

By Don Kissinger, DNR urban forester (Wausau), Don.Kissinger@wisconsin.gov, 715-359-5793 and Paul Cigan, DNR forest health specialist (Hayward), Paul.Cigan@wisconsin.gov, 715-416-4920

To protect oak trees and help prevent oak wilt, the Wisconsin Department of Natural Resources advises people to avoid pruning oaks on their property from April through July.

Spring and early summer pruning makes oak trees vulnerable to oak wilt, a fatal fungal disease that rapidly kills trees in the red oak group and weakens those in the white oak group. Any tree damage during this time creates an opening that exposes live tree tissue and provides an opportunity for the oak wilt fungus to infect the tree.

The red oak group includes northern pin oak, northern red oak, red oak and black oak; the white oak group includes bur oak, swamp white oak, white oak and English oak.

Pin oak (Quercus palustris)

Pin oak (Quercus palustris)
Photo: Gary Fewless, University of Wisconsin, Green Bay

“It takes only a few minutes for beetles that carry oak wilt spores to land on a fresh wound and infect your tree,” said Paul Cigan, DNR forest health specialist in Hayward.

Property owners with oak trees are encouraged to check with their municipality to find out if there are local oak wilt ordinances which may have different pruning restrictions.

The use of tree paint or a wound dressing is not normally recommended on pruning cuts or wounded surfaces on most trees. But for damaged oaks, the use of such products are suggested from April through July. An immediate light painting of wounds or cuts on oak trees during this time helps protect against the spread of oak wilt by beetles.

Don Kissinger, a DNR urban forester in Wausau, said there are also other important reasons to avoid pruning many kinds of deciduous trees in spring beyond concerns about oak wilt.

“Spring is the time when tree buds and leaves are growing, leaving the tree’s food reserves low,” Kissinger said. In general, the best time to prune trees is in winter.

Oak wilt and other diseases move easily on or in firewood logs year-round. To protect trees in general, don’t move firewood long distances, or only use firewood labeled as Wisconsin-certified.

As of January 31, 2018, oak wilt has been found in all Wisconsin counties except Douglas, Bayfield, Ashland, Iron, Forest, Taylor, Door, Kewaunee, Calumet, and Manitowoc counties. Several of these counties contain the highest abundance of healthy and productive oak forests in the state. Taking recommended precautions with living oak trees and keeping firewood local to prevent the spread of oak wilt will help keep them that way for years to come.

More information is available online at the WI DNR website, including a recently released video on oak wilt. Visit the DNR website, https://dnr.wi.gov/, and search for “oak wilt” or “firewood.” Additional information about proper pruning techniques is available from community foresters or by searching for “tree pruning.”

SPECIAL REQUEST from DNR’s Forest Health Team

Thank you to those kind subscribers who have already completed the Forest Health News Survey which was emailed in March. If you haven’t had a chance to take the survey, we ask that you do so now.

Our goal at Forest Health is to provide you with helpful information on pest, disease and invasive plant issues in the state in a timely manner. To help us improve our usefulness to you, please click here to take the survey.

The survey will take about 10 minutes to complete. Your individual responses will be kept confidential. All responses will be compiled and analyzed as a group; a summary of the survey results will be available to you this spring. If you own forested land in Wisconsin, you will need to refer to the zonal map which you will find at the beginning of the survey.

We would be grateful if you will complete the survey by April 15, 2018. If you have any questions or concerns about the survey or wish to provide additional comments about Forest Health News, please contact Jodie Ellis at Jodie.Ellis@wisconsin.gov or at 608-266-2172.

Thank you for taking the time to complete this survey. It is much appreciated.

Statewide quarantine for emerald ash borer

By Jodie Ellis, DNR Forest Health Team, communications specialist (Madison), Jodie.Ellis@wisconsin.gov, 608-266-2172

An adult emerald ash borer.

An adult emerald ash borer.
Photo: Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) enacted a statewide quarantine for the invasive insect emerald ash borer  (EAB) on March 30, 2018. Previously, individual counties were quarantined when EAB was confirmed within each’s borders. Since EAB has been found in 48 of 72 Wisconsin counties, DATCP officials have determined that statewide regulation of the devastating ash tree pest is warranted.

Movement of ash wood, untreated ash products and hardwood firewood of any type to areas outside of Wisconsin will continue to be regulated by USDA’s Animal and Plant Health Inspection Service, Plant Protection and Quarantine. (APHIS PPQ). 

Within the state, Wisconsin businesses and members of the public will be able to freely move ash wood, ash products, and hardwood firewood to or from any Wisconsin county. Firewood restrictions will remain in effect on state and federal lands.

Items affected by the statewide EAB quarantine include ash wood with bark attached, larger ash wood chips, and hardwood firewood of any kind. County-by-county quarantines for gypsy moth, another invasive forest pest, remain in effect.  

The move to a statewide quarantine does not mean that the state has given up on managing EAB; it is simply a shift in strategy as EAB continues its slow spread through the state. The Wisconsin DNR will continue releasing tiny, stingless wasps -natural enemies of EAB – at appropriate sites, which it has done since 2011. The DNR also continues participation in silvicultural trials in which different ash management strategies are being tested.

Most importantly, campers, tourists, and other members of the public are strongly encouraged to continue taking care when moving firewood within the state. “The actions taken by the Wisconsin public during the last few years have significantly slowed the spread of emerald ash borer and other invasive forest pests in the state,” said Wisconsin DNR EAB program manager Andrea Diss-Torrance. “We can continue to protect the numerous areas within our state that are not yet infested – including those in our own backyards – from tree-killing pests and diseases by following precautions.” Public members should continue to obtain firewood near campgrounds or cabins where they intend to burn it, or buy firewood that bears the DATCP-certified mark, meaning it has been properly seasoned or heat-treated to kill pests.

Emerald ash borer is native to China and probably entered the United States on packing material, showing up first in Michigan in 2002. It was first found in eastern Wisconsin in 2008.

For further information on EAB in Wisconsin, visit https://dnr.wi.gov/ using key words “emerald ash borer.”