Forest Health News

Forest Health Team Offers Seven New Fact Sheets, Updates Website

Posted on by akabelowsky
A preview of the new Wisconsin Department of Natural Resources Forest Health fact sheet on spongy moth.

A preview of the new Wisconsin Department of Natural Resources Forest Health fact sheet on spongy moth. Graphic Credit: Wisconsin DNR

By Art Kabelowsky, DNR Outreach/Communications Specialist, Fitchburg; Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

The Wisconsin Department of Natural Resources’ (DNR) Forest Health team has debuted seven new fact sheets, providing information on various forest insects and diseases as well as tips on how to deal with their emergence on your property.

The new fact sheets provide details on spongy moth, oak wilt management, spruce budworm, jack pine budworm, tamarack insects (larch casebearer and eastern larch beetle), red pine pocket decline and mortality and a comparison of common spring defoliator caterpillars (forest tent caterpillar, eastern tent caterpillar and spongy moth).

Additionally, the Forest Health team has updated and/or refreshed the look of its 13 existing fact sheets.

Continue reading “Forest Health Team Offers Seven New Fact Sheets, Updates Website” →

Medford Couple Invests Elbow Grease

Posted on by Kirsten Held

By Art Kabelowsky, Wisconsin DNR Division of Forestry

Lori and Jim Livingston manage a species-diverse, 401-acre property outside Medford and adjacent to the Chequamegon-Nicolet National Forest.

Lori and Jim Livingston manage a species-diverse, 401-acre property outside Medford and adjacent to the Chequamegon-Nicolet National Forest.

What’s one of the most underrated factors behind successful forest stewardship?

Good old-fashioned elbow grease.

“There used to be a time we’d both get up in the morning and work until it got dark,” Lori Livingston said with a laugh. “We don’t do that anymore.”

Still, elbow grease remains the not-so-secret ingredient behind the vast and diverse beauty of Jim and Lori Livingston’s 401-acre property, located adjacent to the Chequamegon-Nicolet National Forest in the Town of Hammel, near Medford in Taylor County.

“The north end is hilly, with a lot of rocks. The south end levels out but gets wet,” Jim Livingston said. “For this part of Wisconsin, we have a lot of diversity.”

“When we first saw this (property), it was just a rockpile,” Lori Livingston said. “Lots and lots of rocks. But we have so many resources here, we’ve been able to make it work.” Continue reading “Medford Couple Invests Elbow Grease” →

Basswood Thrips Causing Crumpled Leaves, Thin Crowns

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665 

Photo of basswood leaves damaged by basswood thrips.

Basswood leaves show damage after feeding of introduced basswood thrips. / Photo Credit: Wisconsin DNR.

For the second consecutive year, damage from introduced basswood thrips (Thrips calcaratus) is significant in some northeastern Wisconsin counties. Introduced basswood thrips are tiny, invasive insects that feed inside tree buds in early spring. Leaves are then deformed when they expand and can look like frost or wind has damaged them.

Continue reading “Basswood Thrips Causing Crumpled Leaves, Thin Crowns” →

Maple Petiole Borer Causes Leaves To Drop

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665

Photo of maple leaf found on the ground with broken petiole (leafstalk).

A green maple leaf found on the ground with a broken petiole (leafstalk) due to damage by the maple petiole borer. / Photo Credit: Wisconsin DNR.

Some sugar maple trees in the northern half of Wisconsin experienced leaves dropping to the ground this spring.

These leaves were green and had no apparent areas of damage, but they covered the ground under some trees. A closer look showed these leaves had short petioles (leafstalks) that had been broken off when they fell, which indicates a tiny sawfly larva called maple petiole borer was to blame.

Continue reading “Maple Petiole Borer Causes Leaves To Drop” →

Watch For Brown Spot Needle Blight

Posted on by akabelowsky
Photo showing white pine with yellowing needles.

White pine with yellowing needles; new growth is not affected. / Photo Credit: Wisconsin DNR.

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665

White pine in north central Wisconsin, as well as scattered areas elsewhere in the state, have many needles that are bright yellow. Brown spot needle blight (Lecanosticta acicula, previously known as Mycosphaerella dearnessii) is the primary suspect, although samples have been sent to the Wisconsin Department of Natural Resources (DNR) Forest Health laboratory to determine if other fungal species are present.

Continue reading “Watch For Brown Spot Needle Blight” →

Lecanium Scale Creating A Sticky Situation

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665

Photo showing ladybug larva feeding on lecanium scale domes.

A ladybug larva feeds on lecanium scale domes on an oak twig. / Photo Credit: Wisconsin DNR.

Lecanium scale is infesting oak forests across Marinette, Oneida and Vilas counties. These scale insects insert their mouthparts into twigs and suck the tree sap. They release honeydew, which ants can collect, or coat leaves and anything located under infested trees (i.e., yard furniture or vehicles). Sooty mold can grow on that sticky material and turn things black, so homeowners may want to rinse off the honeydew from outdoor items regularly.

Continue reading “Lecanium Scale Creating A Sticky Situation” →

Acorn Pip Galls, Woolly Catkin Galls All The Same

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665

Photo of acorns showing small pip galls.

Pip galls are small, tongue-like protrusions emerging from under the caps of acorns. / Photo Credit: Linda Williams, Wisconsin DNR.

Gall wasp life cycles can be complex. Did you know that acorn pip galls, which I’ve written about several times, have another part of their life cycle that is entirely different? This stage is called the woolly catkin gall.

Both woolly catkin galls and acorn pip galls are caused by Callirhytis quercusoperator, a species of cynipid gall wasp. This gall wasp takes two years to complete development by going through the two parts of its life cycle. Both parts of the life cycle are completed on northern red oak in our area.

Continue reading “Acorn Pip Galls, Woolly Catkin Galls All The Same” →

Severe Spruce Budworm Defoliation Hits In Northwest

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff; Linda.Williams@wisconsin.gov or 920-360-0665

Photo taken through magnifying lens of spruce budworm caterpillars.

Spruce budworm overwinters as tiny caterpillars (yellow arrow) that migrate to the buds before they start to swell in the spring. A magnifying lens is needed to see them at this stage. / Photo Credit: Linda Williams, Wisconsin DNR.

For the 11th consecutive year in Wisconsin, spruce budworm has caused significant defoliation on spruce, balsam fir and tamarack in some areas of the state.

This year, areas with widespread severe defoliation include Oneida and Vilas counties, with Forest, Iron, and Langlade counties also showing significant defoliation.

Continue reading “Severe Spruce Budworm Defoliation Hits In Northwest” →

High Beech Scale Moving Beyond Door County

Posted on by akabelowsky

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

and Linda Williams, DNR Forest Health Specialist, Woodruff; linda.williams@wisconsin.gov or 920-360-0665

Photos of white 'wool' coating on trees with beech scale.

Examples of white “wool” coating on trees heavily infested with beech scale at Kohler-Andrae State Park (left) and in the Town of Beecher in Marinette County (right). / Photo Credit: Bill McNee (left) and Linda Williams (right), Wisconsin DNR.

Fourteen years after first detecting beech scale (Cryptococcus fagisuga, a non-native insect) in Door County, sites with high populations of beech scale have been found in additional counties. Beech scale is believed to have spread through the range of American beech in Wisconsin’s eastern counties, but until now has only been seen at low levels outside of Door County.

Continue reading “High Beech Scale Moving Beyond Door County” →

White Pine Weevil Damage And Management Options

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Photo of a white pine tree showing weevil damage.

A dead terminal leader, resulting from an attack by white pine weevil. Photo: Linda Williams, Wisconsin DNR.

White pine weevil (Pissodes strobi) is a native insect that can kill the terminal leader of white pine, jack pine and spruce. Wisconsinites often refer to this insect as Tip Weevil.

The insects prefer to attack stout terminal leaders. When the terminal leader dies, lateral branches grow upward and compete to take over apical dominance. This can leave a noticeable crook for decades. If two or more lateral branches take over, forking can occur. New terminal leaders may be attacked in subsequent years, causing more crook or forking.

Spruce and jack pine tend to recover better from weevil damage than white pine because the lateral branch that takes over apical dominance often creates a less prominent crook.

Continue reading “White Pine Weevil Damage And Management Options” →