The front moves and defenses are built, but there’s no doubt which way the war is going, and little doubt what is emerging the victor: a little green bug.
Agrilus planipennis, the emerald ash borer, has harangued and harassed North American forests since the late 1990s, and its journey across Wisconsin continues, county by county, city by city, tree by tree. But this is not its story. Continue reading “Requiem for an Ash”
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”
By Bill McNee, DNR Forest Health Specialist, Oshkosh. bill.mcnee@wisconsin.gov; 920-360-0942
An aerial view of tree mortality in very wet areas. Photo: Bill McNee
Site visits and aerial surveys conducted on trees in eastern Wisconsin by the Wisconsin DNR forest health team in July and August found multi-species decline and mortality common at many very wet sites. Continue reading “Tree decline and mortality observed at many wet sites this summer”
by Mike Hillstrom, forest health specialist (Fitchburg). Michael.Hillstrom@wisconsin.gov;
208-513-7690
Oak leaf fold galls on red oak leaves. Photo: Mike Hillstrom
Ethan Lee, parks supervisor for the City of Janesville, recently reported symptoms of oak leaf fold galls on an oak tree on the University of Wisconsin – Rock County campus. Oak leaf fold galls, caused by fly larvae, are generally harmless to trees. However, new information links oak leaf galls with a recent invasive mite from Europe, Pyemotes herfsi, commonly called the oak leaf itch mite. Although no evidence of itch mite was found on the affected red oak tree, more than 50% of the tree’s leaves contained leaf fold galls. Continue reading “Oak leaf fold galls and itch mites”
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.
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.
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.
Continue reading “Balsam fir mortality in many counties around the state”
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
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.
By Jodie Ellis, communications specialist, Madison. Jodie.Ellis@wisconsin.gov; 608-843-3506
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.
Continue reading “Forest Health Program welcomes new forest invasive plant coordinator”
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. 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.
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.
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”
