By Bieneke Bron, Midwest Center of Excellence for Vector-Borne Diseases, UW-Madison
Do you ever wonder why you are always finding ticks on yourself or around you, but your friends never do? Researchers at the University of Wisconsin – Madison have developed a mobile application that allows users to share their experiences with ticks to help prevent future tick bites.
Continue reading “The Tick App! ‘Your Tick Expert On-The-Go!’”
Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690
Eastern tent caterpillars (ETC) are hatching and beginning to feed on host trees in Wisconsin, including cherry, apple and crabapple trees. Landowners and homeowners may notice the white silken tents forming in branch forks. Although the tents are unsightly, ETC is a native insect and rarely causes damage. Even completely defoliated trees will put out new leaves within a few weeks.
Eastern tent caterpillars preparing for a day of feeding on a black cherry tree.
Continue reading “Native caterpillars not a major concern for trees”
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Tamarack trees are sending out their needles this spring, and larch casebearer caterpillars are feeding on them. In northern Wisconsin, where the trees didn’t push needles out until the end of May, the caterpillars were impatiently waiting to begin feeding and in some counties the damage is now severe.
Tamarack trees defoliated by larch casebearer will appear straw-colored or tan from a distance. Photo taken May 28 in Oneida County.
Continue reading “Larch casebearer and eastern larch beetle: two problems for tamarack”
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Spruce budworm defoliation is becoming noticeable in northern and central Wisconsin counties as clipped host tree foliage stuck in the caterpillars’ webbing turns rusty red. The caterpillars should pupate soon, and moths will emerge a couple weeks later to mate and lay eggs. Spruce budworm is a native insect with periodic outbreaks that defoliates spruce and balsam fir in the Midwest.
Spruce budworm caterpillar near the silk webbing it spins on branch tips.
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Pine tortoise scales are sometimes found at very heavy densities on jack and scotch pine twigs. In Wisconsin they prefer young jack pine trees, inserting their straw-like mouthparts into twigs and sucking out the sap. When populations are high, pine tortoise scale can cause branch mortality and even whole tree decline.
Pine tortoise scales are so plentiful on this twig that they are practically on top of one another.
Continue reading “Pine tortoise scale can cause branch and tree mortality, sooty mold problems”
Emerald ash borer (EAB) is an invasive insect from Asia that was first introduced into the United States in 2002. Since its discovery, EAB has caused the death and decline of tens of millions of ash trees. Today, the U.S. Department of Agriculture (USDA) is using ash trees against the pest to help preserve and protect the tree species. Staff in the USDA EAB biological control (biocontrol) program are asking Wisconsin landowners in Sheboygan, Fond du Lac and Door counties to help by donating infested ash trees for use in raising wasps that attack and kill EAB.
USDA staff cut a “bark window” in green ash to uncover signs of EAB.
By Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690
2019 was the wettest year ever recorded in Wisconsin. Four of Wisconsin’s top five wettest years have taken place in the last decade, three of them in the last five years: 2019, 2018 and 2016. Flooding can be stressful for trees, and with flooding occurring over the past few years in many parts of the state, forest health staff expect the impacts to forests to continue to escalate. Continue reading “Two-lined chestnut borer in flooded oak stands”
The 2020 gypsy moth slow-the-spread program, operated by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) is expected to begin aerial spraying in the second half of May to slow the westward spread of gypsy moth.
Map of counties where slow-the-spread treatments will occur in 2020.
By Linda Williams, forest health specialist, Woodruff, Linda.Williams@wisconsin.gov, 920-360-0665
Heavy ice and snow loads can cause significant problems for trees. Branches can break under heavy loads, and entire tree tops loaded with snow can come crashing down in windy conditions. Trees that are repeatedly weighed down or tipped over by snow, only to have more snow pile up on them, can be further impacted.
Clockwise from top left: jack pine broken at site of gall on main stem; trees that break at their base due to heavy snow loads are not able to recover; previous attack from pine root collar weevil (yellow arrow) weakened this tree near its base; heavy snow load and a major root weakened by Armillaria caused this tree to break (yellow arrow) and tip over.
By Don Kissinger, urban forester, 715-348-5746, Don.Kissinger@wisconsin.gov or Paul Cigan, plant pest and disease specialist, 715-416-4920, Paul.Cigan@wisconsin.gov
Anyone with oak trees in their yards or on forested lands should avoid pruning or cutting them from April through July to protect them from oak wilt.
Sap-feeding beetle on diseased oak tree in Sawyer County.
Continue reading “Protect oak trees by pruning after July, not before”
