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You can be a star!

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by Jodie Ellis, communications specialist (Madison). Jodie.Ellis@wisconsin.gov; 608-266-2172

Invasive Species Action Month in Wisconsin will be held this year in June. To celebrate, the Wisconsin DNR is teaming up with partners for the “Protect the Places You Play” video challenge. We are looking for video entries from the public (no longer than two minutes, please) that show how you or your group help prevent the spread of invasive species. The winning video’s producer will be invited to attend the Wisconsin Invasive Species Council’s Invader Crusader Awards ceremony on June 6 at Olbrich Botanical Gardens in Madison. Submissions must be received no later than Monday, May 15.

Entries will be voted on by visitors to the DNR’s Facebook page. Voting will be open from May 16 through 25. For instructions on entering your video, see the 2018 Video Challenge page on the Council’s website. Need some inspiration? See last year’s winning submission.

EAB biocontrol releases continue in 2018

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

In 2018, the Wisconsin DNR will complete its eighth year of releasing tiny, stingless wasps as biocontrol agents to help manage emerald ash borer. Columbia, Dane and Grant counties are slated for first-time releases this year, and there will be new release sites in Brown, Door and Sheboygan counties. The wasps will be released for a second year at established sites in Brown, Green, Jefferson, Milwaukee and Sheboygan counties. The same wasps that were released in 2017 will be used this year: Tetra sticus planipennisi, Spathius galinae and Oobius agrili.

Tiny adult Spathius galinae wasps are released near an infested ash tree where they will look for EAB larvae to parasitize

Adult Spathius galinae wasps venture out to find some tasty EAB larvae to parasitize.

 

Map showing the numerous biocontrol sites for emerald ash borer established in southern and eastern Wisconsin since 2011.

Biological control sites for emerald ash borer in Wisconsin 2011-2018. Figure by Bill McNee.

Phomopsis galls

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By Linda Williams, forest health specialist (Woodruff). Linda.Williams@wisconsin.gov; 715-356-5211, x232

Large swellings on the branches of this oak are caused by the fungus Phomopsis.

Large swellings on the branches of this oak are caused by the fungus Phomopsis.

Winter and early spring are great times to look for galls on trees. Some galls, including phomopsis galls, can get very large and, because there are often many galls on a single tree, they are easily spotted from a distance. Phomopsis galls are woody swellings caused by a fungus which range in size from very small to larger than a person’s head. They occur on hickory, northern red oak, maple, and a few other tree species. Infections are usually localized to a single tree with neighboring trees being completely unaffected, or a small group of trees may be infected. Occasionally, larger infection centers can be found.

It is suspected that genetic variability plays a role in the susceptibility of individual trees, but a lot is still unknown about this fungus. There is no known treatment for Phompsis galls other than to prune them out and dispose of them; many people choose to simply live with them. If left on a tree, galls may eventually cause dieback or girdling of infested branches, but some trees live for many decades with galls on their main stems. The presence of galls does not necessarily mean the rapid death of a tree, which is especially true for oak trees: they seem to survive for decades with very large galls present on the branches.

Historical Forest Health News – 1993 and 1968

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News from 25 years ago (1993)

Jack pine budworm – Choristoneura pinus (Rohwer)

Area of defoliation by jack pine budworm in 1993 shaded in black.

Area of defoliation by jack pine budworm in 1993 shaded in black.

“This defoliator erupted in northern and central Wisconsin to cause moderate to heavy defoliation on 400,000 acres of jack pine. This was the second year of defoliation in Clark, Eau Claire and Jackson counties, and first year defoliation in Monroe County. The largest areas of defoliation were in the northwest where periodic outbreaks are expected. Heavy defoliation occurred in Adams, Juneau, Wood, Clark, Eau Claire, Jackson and Monroe counties. Light feeding was apparent in the Conover area of Vilas county. In Oconto county a 90-acre planting of sapling white pine suffered heavy terminal and upper lateral defoliation. Spotty light to moderate defoliation occurred in Oconto and Marinette counties in the northeast. Defoliation in Marinette county was heaviest in over-mature natural stands of jack pine stands in Silver Cliff Township (Sections 22, 23, 27, 26, 34, 35, T34N, RISE).

In Juneau and Wood counties, tree mortality is expected to be high because many trees lost 90 to 100 percent of their foliage. Salvage harvests were scheduled in the defoliated stands that were predicted to suffer heavy mortality. Some of the harvests in the central and westcentral counties were in potential conflict with the protection of the Karner blue butterfly, a newly listed endangered species. Guidelines were developed to survey for the Karner Blue and for its food plant, blue lupine. The guidelines also contain procedures to prevent damage to known Karner Blue habitat during harvest operations. Many defoliated stands that were scheduled for salvage harvests were surveyed. Late season egg mass surveys revealed a 33% decline from 1992 levels in the northwestern counties portending a decrease in populations and defoliation in 1994. In western and central Wisconsin, the egg mass surveys indicate the budworm populations should remain high in 1994. Egg mass surveys in Wood County averaged 5.8 egg masses per plot. Egg mass surveys in Marinette county indicate defoliation will likely be spotty and variable in intensity again in 1994.”

Continue reading “Historical Forest Health News – 1993 and 1968” →

Forest health zones restructured

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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

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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

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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

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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.”

Prepare for the return of gypsy moths

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By Bill McNee, DNR forest health specialist (Oshkosh), bill.mcnee@wisconsin.gov, 920-360-0942

In a few weeks, gypsy moth egg masses will begin hatching in Wisconsin. Property owners interested in reducing gypsy moth populations should consider oiling or removing reachable egg masses well before the hatch begins. Horticultural oils that suffocate the eggs are available at many garden centers and large retailers. In general, these are applied when temperatures are above 40oF and freezing is not imminent. When physically removing egg masses, scrape them into a can of soapy water and then let them soak for a few days before discarding in the trash in order to kill the eggs. Additional management options for homeowners and woodlot owners are available at the Wisconsin gypsy moth website. 

Gypsy moth egg masses

Gypsy moth egg masses

Property owners looking to hire a business to do insecticide treatments this spring should contact them soon. A list of certified arborists is available on the Wisconsin Arborist Association website. Additional businesses offering insecticide treatments may be found in the phone book under ‘Tree Service.’ Homeowners can also purchase insecticides, some of which are applied as soil drenches, at garden centers and large retailers. For larger areas, a list of for-hire aerial applicators is available on the Wisconsin gypsy moth website.

Although this winter’s cold temperatures in late December and early January most likely did not cause heavy egg mortality, the cold period will still help reduce gypsy moth populations this summer. According to the U.S. Forest Service, temperatures of -20°F lasting from 48 to 72 hours can kill exposed eggs. Eggs that are laid higher up on the bark of trees suffer higher mortality than those located near the ground because snow insulates the eggs from cold temperatures. Fluctuating spring temperatures can also cause heavy egg mortality.

2018 suppression spraying:

Dane County will be the only participant in the DNR gypsy moth suppression program in 2018. Aerial spraying will occur in mid- to late May at seven sites in Madison and one site in Sun Prairie. A total of 485 acres will be sprayed with a bacterial insecticide that affects only small caterpillars. Maps of the sites are available on the Wisconsin gypsy moth website.

Slow-The-Spread treatments announced:

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) announced its planned 2018 Slow-The-Spread (STS) gypsy moth treatments in western counties. About 90,000 acres are scheduled for treatment at 36 sites in 14 counties, using low-flying airplanes. Treatments will begin in May and continue through late July or early August, using either bacterial insecticide or pheromones which cause mating disruption.

Map of proposed 2018 gypsy moth aerial treatments.

Proposed 2018 gypsy moth treatments will occur in these counties. Counties in yellow are scheduled for Slow-The-Spread (STS) treatments, while Dane County (in blue) will undergo a suppression spray.

Counties scheduled to receive aerial treatments are: Barron (3 sites covering 2,736 acres); Bayfield (1 site, 787 acres); Buffalo (6 sites, 11,754 acres); Burnett (2 sites, 4,529 acres); Chippewa (4 sites, 12,794 acres); Crawford (4 sites, 5,971 acres); Douglas (1 site, 789 acres); Dunn (5 sites, 43,986 acres); Eau Claire (1 site, 674 acres); Grant (1 site, 497 acres); Green (1 site, 392 acres); Lafayette (2 sites, 527 acres); Rusk (1 site, 463 acres); and Vernon (3 sites, 3,785 acres).

More information on STS treatments may be found online at the DATCP Gypsy Moth website.

Treat your valuable ash trees against emerald ash borer (EAB)

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By Bill McNee, DNR forest health specialist (Oshkosh), bill.mcnee@wisconsin.gov, 920-360-0942

Wisconsin homeowners with healthy, valuable ash trees should consider treating the trees with insecticides this spring to protect against emerald ash borer (EAB). The pest is currently the most damaging threat to trees in the state, killing more than 99 percent of the ash trees it infests. 

Infested ash trees have been attacked by woodpeckers looking for larvae to eat.

Infested ash trees have been attacked by woodpeckers looking for larvae to eat.

Woodpecker damage during the winter is often the first visible sign that an ash tree is infested, so it is important to examine your ash trees during cold months when leaves are absent. Now is a good time to consider protection with insecticides: insecticide treatments are usually applied between mid-April and mid-May once leaves begin to return. Treatments on already-infested ash trees are more likely to be successful if the trees exhibit only low or moderate levels of woodpecker damage.

Emerald ash borer has become so widespread that homeowners should consider treating valuable ash trees no matter where they are located in Wisconsin. The highest risk of EAB-infestation is within quarantined counties or within 15 miles of a known infestation. Outside of these high-risk areas, the danger of ash trees becoming infested with EAB is probably lower, but it is widely believed that there are additional, undetected EAB infestations within the state. A map of known EAB infestations can be found at the Wisconsin EAB website.

Location isn’t the only consideration when deciding whether to begin insecticide treatments. For example, such treatments are not economically practical for woodlot ash trees; they would need to be repeated every 1-3 years for the rest of the trees’ lives (frequency of treatments will depend on the product and method used).

What you should do

If EAB has been found locally or if you see any of the signs or symptoms of an EAB infestation in your ash trees, search for information online or seek advice from a tree care professional. You can fund a certified arborist at the Wisconsin Arborist Association’s website. Other businesses also conduct EAB treatments.

Some insecticide products can be applied by homeowners but others must be applied by a certified professional. Review the available options before selecting an insecticide and treatment method. Insecticide information can be found on the Wisconsin EAB website and EAB Information Network website.

Only ash trees need to be protected against EAB. Mountain ash and prickly ash trees do not need protection from EAB because they are not true ash trees and are therefore not attacked by the insect.

Consider the following

  • Determine whether the tree is worth treating. Some ash trees are too heavily infested to save or have structural or health problems that make them poor candidates for insecticide treatment.
  • Trees displaying large amounts of visible woodpecker damage may be too infested to be saved with insecticides. Consult a certified arborist for a professional opinion.
  • Landscape trees improve views, increase property values, provide shade and cooling, and contribute to the quality of life in a neighborhood. Weigh those benefits against the expense of a treatment.
  • Consider the cost of removing or replacing trees. You might be able to treat your ash tree for more than a decade yet still spend less money than it would cost to remove it.
  • The cost of an insecticide treatment will depend on tree size and the product being used. Some products are applied annually; others are applied every two years.
  • Check the credentials and insecticide applicator certification of any business you hire to treat your ash trees.

Signs and symptoms of an infestation

Stay informed and be on the lookout for emerald ash borer. Know where the pest has already been found and look for the signs and symptoms of EAB infestation. Watch ash trees closely for the following:

  • Woodpecker damage (“flecking”) that looks like pieces of bark have been shaved off and removed;
  • Sprouts growing from the base or trunk of the tree;
  • Thinning leaves in the upper canopy;
  • Tiny (1/8 inch), D-shaped exit holes in the bark; and
  • Adult EAB beetles present during the summer.