Emerald Ash Borer Found In Bayfield County

By Paul Cigan, DNR Forest Health Specialist or 715-416-4920

Emerald ash borer (EAB) has been discovered in Bayfield County for the first time in both the city of Bayfield and Bayview township to the south. This marks the 63rd out of Wisconsin’s 72 counties to have an EAB discovery since its initial detection in 2008.

Dead white ash with woodpecker damage in a park

Figure 1: First known infested ash tree in Bayfield County with characteristic woodpecker damage (i.e., flecking).
Photo: Wisconsin DNR

Several white ash trees (Fig 1.) were observed in and around a roadside park in the city of Bayfield, and larval specimens were subsequently lab-confirmed. In Bayview, a black ash swamp had several infested black ash (Fig 2). 

After introduction, EAB populations remain low for at least several years as most larvae in newly infested, healthy ash require two years to complete their life cycle. The abundance of healthy ash at each site suggests EAB populations have remained low since their introduction at least three years ago. However, EAB will kill ash more quickly as beetle numbers mount and more larvae transform from egg to adult in a single year. Unfortunately, many ash in the area are expected to die within four to seven years based on detection-to-impact timeframes observed from the Superior and Duluth area and research conducted in midwestern states. Continue reading “Emerald Ash Borer Found In Bayfield County”

By Any Other Name, It Is A Pest

By Josh Lancette, Entomological Society of America and Andrea Diss-Torrance, Wisconsin DNR Forest Health

The Entomological Society of America (ESA) has approved “spongy moth” as the new common name for the moth species Lymantria dispar, formerly known as “gypsy moth.”

The ESA gathered a working group of entomologists and forestry professionals to help propose the new name. The name spongy moth—derived from the common name used in France and French-speaking Canada, “spongieuse”—refers to the sponge-like appearance of the egg masses.

The name replaces “gypsy moth” in ESA’s Common Names of Insects and Related Organisms List. The society removed the name in July 2021 for its use as a derogatory term for Romani people.

Learn more about the change from the ESA.

Continue reading “By Any Other Name, It Is A Pest”

Protect Your Valuable Ash Trees Against Emerald Ash Borer

By Bill McNee, DNR Forest Health Specialist, Oshkosh or 920-360-0942

Property owners with healthy, valuable ash trees are encouraged to treat them with insecticide this spring to protect against emerald ash borer (EAB). The pest is currently the most damaging threat to trees in Wisconsin, killing more than 99% of the ash trees it infests.

Ash tree branch in West Allis has been damaged by woodpeckers. Sections of bark are missing or have been flecked away.

This ash tree branch in West Allis has been damaged (“flecked”) by woodpeckers feeding on EAB larvae under the bark.
Photo: Bill McNee, Wisconsin DNR

Continue reading “Protect Your Valuable Ash Trees Against Emerald Ash Borer”

One Last Chance To Treat Or Remove Spongy Moth Egg Masses; DATCP Slow-The-Spread Aerial Treatments Announced

By Bill McNee, DNR Forest Health Specialist, Oshkosh or 920-360-0942

Three tan-colored lumps about the size of a nickel or a quarter are spongy moth egg masses on the underside of a pine branch in Walworth County.

Three spongy moth egg masses on the underside of a pine branch in Walworth County.
Photo: Bill McNee, Wisconsin DNR

Spongy moth* (formerly known as gypsy moth) egg masses typically begin to hatch in April as temperatures warm. Now is a great time to inspect your trees for egg masses and treat or remove any masses within reach. Each mass that hatches may produce up to 1,000 leaf-eating caterpillars.

Populations of spongy moths increased in 2020 and 2021 due to favorable weather conditions. This winter’s temperatures have not been cold enough to cause heavy egg mortality. A large rise in caterpillar numbers can be expected in 2022 if weather conditions are warm and dry over the next few months.

Continue reading “One Last Chance To Treat Or Remove Spongy Moth Egg Masses; DATCP Slow-The-Spread Aerial Treatments Announced”

EAB Identified In Lincoln County For The First Time, Continues Spread Into Northern Wisconsin

By Linda Williams, WI DNR Forest Health Specialist, Woodruff or 920-360-0665

Emerald ash borer (EAB) continues to spread into areas of Northern Wisconsin and was detected for the first time in Lincoln County, in the Town of Harrison and the City of Tomahawk. EAB was first identified in Wisconsin in 2008, only 14 years ago. It is now in 62 of Wisconsin’s 72 counties.

S-shaped markings in an ash tree trunk where a hatchet has removed the bark.

S-shaped galleries under the bark of this ash were created by EAB larvae. You can also see epicormic branches (water sprouts) coming out of the trunk. These are a sign of significant stress in the tree. Photo Credit: Wisconsin DNR

Continue reading “EAB Identified In Lincoln County For The First Time, Continues Spread Into Northern Wisconsin”

90 New Municipal Detections Of Emerald Ash Borer In 2021

By Bill McNee, DNR Forest Health Specialist, Oshkosh, or 920-360-0942

In 2021, emerald ash borer was found in 90 more communities in Wisconsin than in 2020, including 10 cities, 14 villages and 66 towns. This increased the total number of communities with a reported emerald ash borer detection 11% to 898 at the end of 2021.

Emerald ash borer was confirmed for the first time in Barron, Iron and Langlade counties during the year. It has now been found in 61 of Wisconsin’s 72 counties and confirmed on Oneida Nation land, and we believe additional unreported infestations are present.

Municipal emerald ash borer detections during 2021 are shown in orange. Older detections are shown in green or blue. Map courtesy of Wisconsin Department Agriculture, Trade and Consumer Protection.

Continue reading “90 New Municipal Detections Of Emerald Ash Borer In 2021”

Upcoming Webinars: EAB University And TREE Fund

The EAB University Spring 2022 Webinars are right around the corner. All webinars are free, and many count towards continuing education programs.

Can’t watch them live? No problem! All webinars are recorded and posted afterward.

Check out the EAB University Spring 2022 webinars and register for them here. All sessions begin at 10 a.m. CST.

  • Feb. 24: The Biology and Management of the Invasive Spotted Lanternfly. Holly Shugart, Ph.D. Postdoctoral Scholar, Pennsylvania State University
  • March 1: Firewood Rules, Certifications, and Recommendations across the USA.
    Leigh Greenwood, Forest Health Program Director, North America Region, The Nature Conservancy 
  • March 3: The Worst Kind of Snowbird: The Invasion of Asian Longhorned Beetle in South Carolina. David Coyle, Assistant Professor and State Extension Specialist, Clemson University 

Continue reading “Upcoming Webinars: EAB University And TREE Fund”

Climate Impacts On Forest Insects

Climate change may impact forest insects in a variety of ways that will likely put stress on the forest. Warmer temperatures, altered precipitation patterns, more frequent extreme weather events and longer growing seasons are a few consequences of climate change that may shape the effects of insects in future forests. A changing climate may impact insects as:

  • Warmer temperatures accelerate larval development and increase insect populations.
  • Extended growing seasons allow for more generations of insects each year.
  • Altered leaf chemistry modifies insect host plant preferences.
  • Extreme weather events damage and stress forests, resulting in attacks by native and non-native insects.
  • Warmer temperatures allow insects to expand their range and occupy new areas.

Many examples of insects responding to climate change have already been documented. Two examples are:

1) Mountain pine beetle expanding its geographic range in the western U.S. and infesting a new host tree species during the most recent outbreak; and

2) Eastern larch beetle having an additional generation each year that has resulted in an unprecedented 20-year outbreak in Minnesota. Continue reading “Climate Impacts On Forest Insects”

Forest Health In The Statewide Forest Action Plan

The forest health chapter of Wisconsin’s 2020-2030 Statewide Forest Action Plan, completed in June 2020, highlights the impacts of insects, diseases, invasive plants and worms in Wisconsin’s forests.

Forest health experts from government agencies, universities and tribes worked together to evaluate these current impacts. They then developed goals and strategies to help the forestry community refine how it will invest state, federal and partner resources to address major forest health management and landscape priorities over the next ten years.

Forest health is a critical component of the plan because native and non-native pests increase tree mortality to a level that negatively affects forest stocking levels, clean water, wildlife habitat and raw material for wood products. This causes economic losses and undesirable management outcomes. Continue reading “Forest Health In The Statewide Forest Action Plan”

Planting and Seeding Trials In The Wake Of Ash Decline

Swamp White Oak seedling planted in a black ash replacement trial. Credit: Wisconsin DNR

The emerald ash borer (EAB) is causing widespread mortality of both upland and lowland ash. Black ash (and to a lesser extent green ash) is a forest wetland species that helps prevent sites from swamping through evapotranspiration. With the loss of ash in these systems, forest practitioners are developing silvicultural strategies to minimize the impacts through planting and seeding trials.