Statewide Forest Health

Pine tortoise scale can cause branch and tree mortality, sooty mold problems

Posted on June 5, 2020June 5, 2020 by margueriterapp

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

Pine tortoise scales are sometimes found at very heavy densities on jack and scotch pine twigs. In Wisconsin they prefer young jack pine trees, inserting their straw-like mouthparts into twigs and sucking out the sap. When populations are high, pine tortoise scale can cause branch mortality and even whole tree decline.

Tiny pine tortoise scales clustered on a pine branch tip.

Pine tortoise scales are so plentiful on this twig that they are practically on top of one another.

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Educational HRD video now available

Posted on May 5, 2020May 7, 2020 by margueriterapp

By Kyoko Scanlon, forest pathologist, Kyoko.Scanlon@wisconsin.gov, 608-235-7532

The Wisconsin DNR recently created a short video on Heterobasidion root disease (HRD) to compliment the updated guidelines that were released in 2019. The 5-minute educational video covers HRD biology, its significance as a tree disease, signs and symptoms, as well as preventative measures that landowners can take to reduce its introduction and spread. This is a great video for forestry professionals, landowners and the general public to learn more about HRD. Continue reading “Educational HRD video now available” →

USDA seeks ash trees to battle EAB

Posted on May 5, 2020May 14, 2020 by margueriterapp

Emerald ash borer (EAB) is an invasive insect from Asia that was first introduced into the United States in 2002. Since its discovery, EAB has caused the death and decline of tens of millions of ash trees. Today, the U.S. Department of Agriculture (USDA) is using ash trees against the pest to help preserve and protect the tree species. Staff in the USDA EAB biological control (biocontrol) program are asking Wisconsin landowners in Sheboygan, Fond du Lac and Door counties to help by donating infested ash trees for use in raising wasps that attack and kill EAB.

A square window of bark is removed from green ash to uncover EAB larvae underneath.

USDA staff cut a “bark window” in green ash to uncover signs of EAB.

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Proposed guidance available for public comment

Posted on May 5, 2020May 14, 2020 by margueriterapp

By Bill McNee, forest health specialist, Oshkosh, Bill.Mcnee@wisconsin.gov, 920-360-0942

The DNR Forest Health Program currently has proposed guidance, “Organizing an aerial spray for forest pests: Recommendations and regulations,” available for public comment until May 25. The document can be found on the proposed DNR program guidance webpage under “new proposed program guidance.” Comments can be submitted through this webpage.

Cover page of proposed aerial spray guide.

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DATCP pesticide certifications during COVID-19

Posted on May 5, 2020 by margueriterapp

By Becky Gray, forest health team leader, Fitchburg, Rebecca.Gray@wisconsin.gov, 608-220-3022

Due to COVID-19, the Department of Agriculture, Trade and Consumer Protection (DATCP) is extending pesticide certifications. If your pesticide certification will expire between January 31^st and September 30^th, then your certification is now valid until October 31^st. Please refer to DATCP’s press release for more details.

If you were planning to take the test for pesticide certification this spring, DATCP is offering online pesticide exams for certain categories, including Forestry Category 2.0. The online exams are only for a temporary pesticide applicator certification which will be good until October 31st. Please refer to DATCP’s press release explaining the online pesticide exams for more information.

Two-lined chestnut borer in flooded oak stands

Posted on May 5, 2020 by margueriterapp

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

2019 was the wettest year ever recorded in Wisconsin. Four of Wisconsin’s top five wettest years have taken place in the last decade, three of them in the last five years: 2019, 2018 and 2016. Flooding can be stressful for trees, and with flooding occurring over the past few years in many parts of the state, forest health staff expect the impacts to forests to continue to escalate. Continue reading “Two-lined chestnut borer in flooded oak stands” →

White pine blister rust can girdle branches

Posted on May 5, 2020May 5, 2020 by margueriterapp

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

White pine branches that suddenly turn red may be a sign of white pine blister rust. White pine blister rust is a fungal infection that creates expanding “dead spots” or cankers on the branches or main stem of host trees. Eventually the fungus grows enough to girdle the branch or main stem and the needles fade from green to pale green to rusty red. Orange, spore-producing pustules erupt around the edges of the canker in the spring.

Orange pustules erupt through the bark and around the margins of a white pine blister rust canker. Photo by Jean Romback-Bartels.

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Protect oak trees by pruning after July, not before

Posted on March 30, 2020April 20, 2020 by margueriterapp

By Don Kissinger, urban forester, 715-348-5746, Don.Kissinger@wisconsin.gov or Paul Cigan, plant pest and disease specialist, 715-416-4920, Paul.Cigan@wisconsin.gov

Anyone with oak trees in their yards or on forested lands should avoid pruning or cutting them from April through July to protect them from oak wilt.

Sap-feeding beetle on diseased oak tree in Sawyer County.

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Severe spruce needle diseases expected in 2020

Posted on March 30, 2020March 30, 2020 by margueriterapp

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

Wet weather in 2019 created ideal conditions for Rhizosphaera kalkhoffii and other needle cast fungi to infect spruce needles. Since it takes about a year for the needles to show symptoms, heavy and widespread needle diseases are expected to be seen on spruce trees in 2020.

Lower branches of an infected spruce tree have lots of missing needles and some that are browning.

Loss of older needles on an infected spruce.

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Prepare for the return of gypsy moths in spring