Statewide Forest Health

Be on the lookout for beech leaf disease

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

Early striping from BLD as seen looking up into the canopy. Photo: The Ohio State University.

Early striping from BLD as seen looking up into the canopy. Photo: The Ohio State University.

Although beech leaf disease (BLD) has not been found in Wisconsin, forest owners and managers should keep an eye out for it on American (Fagus grandifolia) and, to a lesser extent, European (Fagus sylvatica) beech trees. Beech leaf disease is becoming a serious issue in parts of Ohio, Pennsylvania, New York and Ontario. Its cause is not yet known.

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Balsam fir mortality in many counties around the state

Counties shaded in blue are where balsam mortality has been reported, but the is even more widespread than this map indicates.

Counties shaded in blue are where balsam mortality has been reported, but it is even more widespread than this map indicates.

By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665 and Paul Cigan, forest health specialist, Hayward Paul.Cigan@wisconsin.gov, 715-416-4920

Reports of balsam fir suddenly turning rusty red to brown and dying have been coming in steadily this spring and summer. The accompanying map shows where this has been reported so far this year.

Spoiler alert! There are no insect or diseases involved. It appears the cause may be unusually severe winter drying or winter damage.

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Fall webworms start making an appearance

By Todd Lanigan, forest health specialist, Eau Claire, WI. Todd.Lanigan@wisconsin.gov; 715-210-0150

A silken nest full of caterpillars, excrement and debris. Photo: Todd Lanigan

A silken nest full of caterpillars, excrement and debris. Photo: Todd Lanigan

Web-like nests of fall webworm (Hyphantrea cunea) caterpillars, a common native pest active from July through September, are beginning to appear in parts of the state. A common native pest throughout most of the U.S. and southern Canada, fall webworm caterpillars feed on leaves of almost all shade, fruit, and ornamental trees and shrubs, except for conifers. They typically form nests of loose webbing over the tips of tree branches.  Although populations of fall webworm caterpillars are rarely large enough to cause lasting damage to trees, the presence of nests and feeding damage from caterpillars can greatly affect trees’ aesthetic value. Typically, trees recover from feeding damage on their own, but defoliation for more than two or three years in a row could make trees more susceptible to diseases and pests.

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Forest Health Program welcomes new forest invasive plant coordinator

By Jodie Ellis, communications specialist, Madison. Jodie.Ellis@wisconsin.gov; 608-843-3506

Michael Putnam

Michael Putnam, DNR Forestry’s new forest invasive plant coordinator.

The Forest Health Program is excited to welcome Mike Putnam as its new forest invasive plant coordinator. Mike has been working with the program as an LTE for more than four years in Madison; his new position is in Rhinelander. He’ll be focusing on invasive plants prevention and management with DNR foresters and partners, so please reach out to him with field work opportunities.

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White pine bast scale and fungus

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

Branches in the mid- and lower-crown of this white pine are being killed by white pine bast scale and a fungal disease.

Branches in the mid- and lower-crown of this white pine are being killed by white pine bast scale and a fungal disease. Photo: Linda Williams

White pine bast scale and canker fungus has been identified in two sites in Oneida County. This insect/fungus complex is a new issue in the state; those who work with white pine should be alert for signs and symptoms.

White pine bast scale, a native scale, is tiny, black, oval-shaped, and lacks both eyes and legs. It uses a long stylet to siphon sap from outer layers of phloem (bast) of twigs and branches. White pine bast scales live under lichens on white pine branches. Although lichens don’t directly harm trees, they provide shelter for scale insects.

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Forestry partners take lead in 2018 EAB trapping

By Paul Cigan, forest health specialist, Hayward. Paul.Cigan@wisconsin.gov; 715-416-4920

As summer approaches, adult emerald ash borer (EAB) beetles are beginning to emerge to feed and reproduce.

Areas of possible initial EAB emergence.

USDA APHIS EAB emergence map. Map credit: USDA Cooperative Emerald Ash Borer Project

Due to the recent statewide quarantine for emerald ash borer and workload considerations, USDA’s Animal and Plant Health Inspection Service, Plant Protection and Quarantine (APHIS PPQ), the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), and the Wisconsin DNR Forest Health Program have discontinued trapping programs for adult beetles in Wisconsin. Continue reading “Forestry partners take lead in 2018 EAB trapping”

Eastern tent caterpillar and control options

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

Young eastern tent caterpillars on their web nest. Photo: Linda Williams

Young eastern tent caterpillars on their web nest. Photo: Linda Williams

Winter is finally over and eastern tent caterpillars are hatching and building their web nests! In northern Wisconsin, the caterpillars began hatching in early to mid-May, but they emerged earlier in southern Wisconsin. Webs will become larger as the caterpillars feed and grow. Continue reading “Eastern tent caterpillar and control options”

Trapping for non-native beetles

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

A Lindgren funnel trap hung to collect beetles near Green Bay, WI. Photo: Mike Hillstrom

Scott Schumacher, an insect trapper for the Wisconsin DNR’s forest health team, will spend this summer hunting for non-native beetles using funds provided by the U.S. Forest Service. The survey is particularly focused on non-native bark and ambrosia beetles, which are potentially harmful to Wisconsin forests. In early May, Schumacher hung Lindgren funnel traps at 12 sites in Wisconsin which he will be checking throughout the season. Traps were placed at high-risk sites in wooded areas near large commercial port entries on Lake Michigan and near pallet and other waste-packaging recycling companies. Although preventing the arrival of non-native species is always top priority, early detection and rapid response (EDRR) to newly-detected infestations is an important strategy to protect forests from damaging invaders.

Ladybugs in your house this spring?

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

One option for removal of ladybugs from your home is to flick them into a small container containing soapy water, which will kill them.

One option for removal of ladybugs from your home is to flick them into a small container containing soapy water, which will kill them. Photo: Linda Williams

In the December 2017 edition of Forest Health News, I wrote about ladybugs congregating in or on homes during autumn. Now that winter has finally ended in Wisconsin, ladybugs that spent winter in the walls of your house are emerging, and many of those will accidentally emerge into, not out of, your home. This can create panic or aggravation, depending on you (or your spouse’s) tolerance for insects in the house. Continue reading “Ladybugs in your house this spring?”

Tree mortality in low areas

Trees have grown in this low area for many years, but high-water levels and constant rainfall in 2017 was too much for them. The larger trees have already died, and the small white pine are not doing well at all.

Trees have grown in this low area for many years, but high-water levels and constant rainfall in 2017 was too much for them. The larger trees have already died, and the small white pine are not doing well at all. Photo: Linda Williams

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

I continue to get calls about dying trees that are a direct result of all the rainfall we got throughout last year’s growing season. When the ground is saturated so many times throughout the growing season as we saw last year, trees are put under significant stress. Even trees that typically grow well in seasonally wet areas may not do well when the ground is wet for extended periods. Under these conditions, roots start to die due to lack of oxygen, and the crown of the tree will also die back.  Continue reading “Tree mortality in low areas”