Forest Health News

Return of Asian multicolored ladybugs

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

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

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”

Upcoming forest health events

CONFERENCES

OCTOBER 15-18, 2018. Mayo Civic Center, 30 Civic Center Drive SE, Rochester, MN
Upper Midwest Invasive Species Conference / North American Invasive Species Management Association
The Upper Midwest Invasive Species Conference (UMISC) is a biennial conference celebrating 10 years of connecting the invasive species management, research, and policy community. The Conference host organizations and organizing committees are pleased to join with the North American Invasive Species Management Association (NAISMA), celebrating its 25th year, to co-host the largest invasive species conference in North America at the Mayo Civic Center in Rochester, MN – October 15-18, 2018. The goal of UMISC is to strengthen management of invasive species, especially prevention, control, and containment. Invasive species research, prevention, and management has seen great strides but much work still must be done. The conference provides numerous opportunities to network with professionals, land managers, researchers, nonprofits, and others.   The conference is open to the general public. Registration with fees required.

TALKS

OCTOBER 13, 2018. Boerner Botanical Gardens, 9400 Boerner Drive, Hales Corner, WI.
10:00-11:30AM
“Invasive Plants”. Mary Bartkowiak, invasive plants specialist, WI DNR Forest Health Program.
Mary’s presentation will focus on invasives in the marketplace (aka Organisms in Trade) and an overview of the NR 40 invasive species rule. Open to SEWMG Master Gardeners. Registration required.

OCTOBER 15, 2018. Holiday Inn Convention Center, 1001 Amber Ave, Stevens Point, WI
71st Annual Wisconsin Towns Association meeting (October 14-16).
“Enemies of the Town – Insects, Diseases, Invasive Plants and Worms impacting Wisconsin in 2018”. Mike Hillstrom, forest health specialist, WI DNR Forest Health Program.
Talks begin at 8:30AM. The meeting is open to the general public. Registration with fees required.

Emerald ash borer detected in Kewaunee County

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

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

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

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

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

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)”