Insect

Fighting invasives together through responsible firewood practices

By Marguerite Rapp, forest health communications specialist, marguerite.rapp@wisconsin.gov, Andrea Diss Torrance, invasive insects program coordinator, andrea.disstorrance@wisconsin.gov, and Tim Allen, DATCP forest pest program coordinator and nursery inspector, timothy.allen@wisconsin.gov, 715-891-8158

This time of year, many Wisconsinites warm up with firewood, whether that’s in a wood stove for the home or a bonfire with family and friends. While firewood is one of the most sustainable heat sources available, the forests that produce it are threatened when firewood infested by invasive species is moved long distances. Fortunately, we can reduce this threat together through responsible use, movement and sale of firewood and wood products.

Man loads firewood into arms from back of truck. Continue reading “Fighting invasives together through responsible firewood practices”

Check your trees for EAB and plan for spring

By Bill McNee, forest health specialist, Oshkosh, bill.mcnee@wisconsin.gov, 920-360-0942

The cold winter months are a great time to think about emerald ash borer and whether ash trees in your yard are suitable for treatment. The pest is currently the most damaging threat to trees in Wisconsin, killing more than 99 percent of the ash trees it infests.

Two side-by-side images depicting different stages of flecking on ash trees - on left side is light flecking in the upper canopy of a tree, on the right side is more severe flecking that extends down the trunk of the tree

Woodpecker flecking is an early sign of EAB infestation when it appears in the tops of trees (left). As the infestation progresses, flecking continues down the trunk and into lower parts of the crown (right).

Continue reading “Check your trees for EAB and plan for spring”

Protect your trees from disease by pruning when they have no leaves

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

With the new year upon us, healthy lifestyle habits are sure to be on many people’s minds as they plan for changes in diet and exercise. The new year is also the perfect opportunity to make healthier choices for trees! Winter is the ideal time for tree pruning while avoiding harmful, disease-carrying pests such as the tiny beetles that carry oak wilt from one tree wound to another.

Woman pruning a tree with no leaves on it.

Pruning during winter is less likely to invite unwanted, disease-carrying pests like the beetles that carry oak wilt from one tree to another. Credit: sasapanchenko.

Continue reading “Protect your trees from disease by pruning when they have no leaves”

2019 Forest Health Annual Report now available

Forest health annual report now available for 2019.

The Forest Health Annual Report summarizes notable impacts for that year of pests, diseases and weather on the health of Wisconsin’s forests. The report is a collaborative product created by DNR forest health specialists from around the state. It outlines the damage and spread of both native and invasive pests and diseases during that year and puts these into context of observations from previous years. Management programs and their results are also described. Highlights from the 2019 annual report include:

  • Dramatically increased decline and mortality from emerald ash borer in southern WI
  • New county and township detections of oak wilt
  • Precipitation record and major storm damage
  • Summary of state nursery studies on Diplodia sapinea, galls on jack pine seedlings, and testing new fumigants to replace methyl bromide

This year’s annual report is available on the DNR forest health homepage. Previous annual reports, including historical reports dating back to 1951, are archived and available upon request. Contact your local forest health specialist if you’d like digital copies of any archived annual reports.

Snow fleas spring to surface in early December

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

Snow fleas are a species of springtails that are active during winter and are generally found in groups where their dark-colored bodies stand out against the white snow. While often observed in late winter or early spring, they also come to the surface on warm winter days, making an early December appearance in west central Wisconsin something to note but not altogether unusual given the relatively warm weather in the area. 

Tiny flecks against an impression in snow are hundreds of snow fleas at surface.

Easily mistaken for specks of dirt or debris, snow fleas are tiny soil-dwelling animals that gather on the surface of snow on warm winter and spring days.

Continue reading “Snow fleas spring to surface in early December”

New map illustrates damage from EAB

Forest health staff recently produced a map that highlights a gradient of damage from southeastern to northwestern Wisconsin, which roughly corresponds to the length of time EAB has been present in these parts of the state. Whatever the level of damage, homeowners and landowners should consider treating healthy ash, including trees that have responded well to previous treatments, or removing declining, untreated ash before they become hazardous and even more costly to remove.

County-level map of damage from EAB to ash tree populations in 2019

County-level assessment of damage to ash population by emerald ash borer, 2019.

Continue reading “New map illustrates damage from EAB”

Invasive plants, ticks and you

Most people are familiar with the impacts of invasive plants to natural areas, but did you know that invasive plants can be hazardous to human health? Did you also know there is a new app available to learn about tick activity near you and help researchers by recording your own tick encounters?Forested setting with tree in foreground and sign attached to tree that says beware of ticks. Continue reading “Invasive plants, ticks and you”

Pine wood nematode in Waushara County

By Alex Feltmeyer, forest health specialist, Plover, alexandra.feltmeyer@wisconsin.gov, 715-340-3810

Pine wood nematode (PWN) was recently found to be infecting Scotch pine in Waushara County. Symptoms of pine wood nematode include rapid crown browning (within 3 months) in late summer, rapid drying of wood and presence of blue-stain fungi in the wood.

Row of pine trees with browning needles from pine wood nematode infestation.

Symptomatic trees dying from pine wood nematode. Photo by Alex Feltmeyer. 

Continue reading “Pine wood nematode in Waushara County”

Are you planning to treat your ash trees? If not, stay safe and save money by removing them ASAP!

The emerald ash borer (EAB) will kill nearly all of Wisconsin’s ash trees that are not protected by insecticides. If you have healthy ash trees in your yard, you have an important decision to make: protect your trees with insecticides or have them removed. Either way, time is of the essence. If you delay in treating your ash trees, the treatment may be less effective. And if you wait to remove them, removal costs will be greater and safety hazards will only get worse.

Credit: Joseph O’Brien, USDA Forest Service, Bugwood.org

What makes infested trees so dangerous?

The structural integrity, or strength, of ash branches and tree trunks begins to decline as soon as the tree becomes infested and the wood begins to dry. Lower moisture content increases the risk of branch and trunk breakage, and the timing of breakage is usually unpredictable. Infested trees may also have total trunk failure soon after death, further increasing the chance of dangerous impacts to people and property.

Continue reading “Are you planning to treat your ash trees? If not, stay safe and save money by removing them ASAP!”

Dead and dying ash are hunting hazard

By Bill McNee, forest health specialist, Bill.McNee@wisconsin.gov, 920-360-0942 and Andrea Diss-Torrance, invasive forest insects program coordinator, Andrea.DissTorrance@wisconsin.gov, 608-264-9247

Hunters should avoid placing tree stands in or near ash trees, especially in the southern half of Wisconsin, the Mississippi River region and in Door County. Many ash trees in these areas are dead or dying from attack by emerald ash borer (EAB), becoming weaker and more likely to break even with little to no added weight. Continue reading “Dead and dying ash are hunting hazard”