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Public comment period for HRD treatment guidelines revision closes October 16

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A fruiting body of Heterobasidion irregulare at the base of a pine tree.

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

Wisconsin DNR is seeking public comments on a proposed revision to preventative treatment guidelines for Heterobasidion root disease (HRD). Stand-level HRD treatment guidelines were originally released in 2013. A DNR technical team and stakeholder advisory committee proposed a revised version using recent research findings, operational experience, and economic considerations.

The draft document and information about the public comment process can be found at  https://dnr.wi.gov/news/input/Guidance.html#open through Tuesday, October 16, 2018. All comments must be submitted by that date.

Leaf-browning on white and burr oaks

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

Dying leaves on white oak. Photo: Mike Hillstrom.

Dying leaves on white oak. Photo: Mike Hillstrom.

During late August and September of this year, Forest Health staff received several comments about problems with white and burr oaks. Leaves on affected trees turned brown, curled and died prematurely. Some trees were almost completely affected, while others only mildly. Symptoms varied widely between trees, even between those located next to each other. After examining several samples, the DNR Forest Health Lab concluded that damage was likely caused by fungal leaf pathogens and the twig canker fungus Botryosphaeria. Because the damage occurred late in the growing season, afflicted trees will not likely suffer major impacts. Although Botryosphaeria can cause twig dieback, oak trees usually recover without long-term problems. Continue reading “Leaf-browning on white and burr oaks” →

Return of Asian multicolored ladybugs

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

Multicolored Asian ladybeetles, true to their name, come in a range of colors, from orange to red, with a variety of spot sizes and numbers.

Multicolored Asian ladybeetles, true to their name, come in a range of colors, from orange to red, with a variety of spot sizes and numbers. Photo: Linda Williams

Multicolored Asian ladybeetles are not native to Wisconsin. Although there are numerous native ladybugs in the state, only the Asian variety are known to aggregate in buildings in the fall and become nuisances. Continue reading “Return of Asian multicolored ladybugs” →

Pine root collar weevil

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

This jack pine is leaning due to damage at its base from pine root collar weevil. Photo: Linda Williams

This jack pine is leaning due to damage at its base from pine root collar weevil. Photo: Linda Williams

Damage from pine root collar weevils was recently reported in Lincoln, Marinette, and Vilas counties on jack pine trees. Pine root collar weevils are known to attack and kill all types of pines, although scotch, red, and jack pine are the most common hosts in Wisconsin. The insects attack pine trees of varying sizes – from large saplings to those of small pole size. Adult weevils deposit eggs at the tree’s base; larvae then bore under bark and feed in the root collar area, effectively girdling the tree. Soil and bark near the root collar becomes blackened and soaked with pitch. Feeding larvae are visible in tunnels under the bark. Continue reading “Pine root collar weevil” →

Oak branch tips laying on the ground this fall

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

An oak branch tip clipped by a squirrel and dropped to the ground. Photo: Linda Williams

An oak branch tip clipped by a squirrel and dropped to the ground. Photo: Linda Williams

Forest health specialists in the northern part of the state recently received reports of oak trees suddenly losing branch tips (complete with attached leaves). Preliminary examinations of cut/branches did not initially reveal any obvious problems. However, upon closer inspection, teeth marks from squirrels were found on many of them. Squirrels were even observed clipping oak branches and dropping them to the ground. Continue reading “Oak branch tips laying on the ground this fall” →

Emerald ash borer detected in Kewaunee County

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Communities known to have emerald ash borer as of September 2018 are shown in green, with Kewaunee County highlighted in red. Modified from a map by the Wisconsin Dept. of Agriculture, Trade and Consumer Protection (DATCP).

Communities known to have emerald ash borer as of September 2018 are shown in green, with Kewaunee County highlighted in red. Modified from a map by the Wisconsin Dept. of Agriculture, Trade and Consumer Protection (DATCP).

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

In August, two separate infestations of emerald ash borer (EAB) were found in rural areas of Kewaunee County. EAB has spread through Wisconsin over the last few years, so these detections were expected. The first infestation spans the towns of Carlton and Franklin in the southern part of the county. A county resident reported the second infestation, located in the Town of Casco, in late August. The pest is likely present in other parts of the county as well.

Public comment period for EAB silviculture guidelines revision closes October 9

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

Ash trees dying from an EAB infestation. Photo: Troy Kimoto, Bugwood.org

Ash trees dying from an EAB infestation. Photo: Troy Kimoto, Bugwood.org

The Wisconsin DNR is seeking public comments on a proposed revision to silviculture guidelines for emerald ash borer (EAB). Stand-level EAB silviculture guidelines were originally released in 2007, with periodic reviews and updates. A DNR technical team and stakeholder advisory committee prepared the current version using multiple sources of information, including recent research findings, identification and locations of new EAB infestations, economic considerations, and experience gained from implementing previous versions of the guidelines.

The draft document and information about the public comment process can be found at  https://dnr.wi.gov/news/input/Guidance.html#open through Tuesday, October 9, 2018. All comments must be submitted by that date.

Look for gypsy moth egg masses

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By Bill McNee, DNR Forest Health Specialist, Oshkosh. bill.mcnee@wisconsin.gov; 920-360-0942

Gypsy moth egg masses. Photo: Bill McNee

Fall is an excellent time to look for and dispose of gypsy moth egg masses produced by adult moths this summer. Gypsy moth egg masses are felt-like, tan-colored patches about the size of a nickel or quarter that gypsy moth females deposit in protected places. Surveying for egg masses helps property owners predict how high populations of the insect will be during the subsequent spring and summer. Since egg masses usually don’t hatch until April, information gained from fall/winter surveys can be used to mitigate gypsy moth damage before the following season.  Continue reading “Look for gypsy moth egg masses” →

Spruce needle rust not an issue this year

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

Orange fruiting bodies of spruce needle rust erupt from needles. From a distance, the tree appears orange due to colored pustules on the needles. Photo: Linda Williams

Orange fruiting bodies of spruce needle rust erupt from needles. From a distance, the tree appears orange due to colored pustules on the needles. Photo: Linda Williams

Occurrences of spruce needle rust in northeastern and north central Wisconsin is low this year for the first time since 2013. Spruce needle rust, caused by the fungus Chrysomyxa weirii, infects spruce needles. Fruiting structures erupt from needles in August in shades of pink, yellow, and orange, greatly affecting the appearance of the trees. In addition, infected needles drop off, causing trees to look sparse.

No treatments are available for already-infected needles. Preventative fungicide treatments for yard trees may be used the following spring and early summer, but treatments must be applied before symptoms appear. Repeated treatments will be necessary; the fungicide, which must fully coat needles to be effective, washes or wears off over time.

Brown branch tips on jack pine

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

After brushing away sawdust, exit/entrance holes, as tiny as the beetles themselves, become visible. A beetle is inside, peeking out. The marks at the bottom of the photo depict millimeters.

After brushing away sawdust, exit/entrance holes, as tiny as the beetles themselves, become visible. A beetle is inside, peeking out. The marks at the bottom of the photo depict millimeters.

Jack pine tip beetle (Conopthorus banksianae) is a tiny bark beetle that bores into the twig tips of pines. Damage from jack pine tip beetle was observed this summer on jack pine trees in Marinette, Vilas, and Lincoln counties and on white pine in Waupaca County. These beetles attack and kill the outer 4-6 inches of twigs, leaving hollow piths. The piths can be diagnostic in determining whether an insect or disease killed the branch tip. The damage, which may appear significant since the dead needles remain on the branch tip and there can be many dead branch tips on a single tree, is rarely severe enough to be detrimental to the tree; no control is recommended.

Jack pine tip beetles kill the outer few inches of twigs. The two yellow circles show where sawdust was pushed out of the twig by adult beetles. Photos: Linda Williams

Jack pine tip beetles kill the outer few inches of twigs. The two yellow circles show where sawdust was pushed out of the twig by adult beetles. Photos: Linda Williams