Forest Health News

Sparse-leafed elms and maples

Posted on by jodieellis
Heavy seed production by a red maple. The Ohio State University.

Heavy seed production by a red maple. The Ohio State University.

By Todd Lanigan, forest health specialist, Eau Claire. todd.lanigan@wisconsin.gov, 715-210-0150 and Paul Cigan, forest health specialist, Hayword. Paul.Cigan@wisconsin.gov, 715-416-4920

There have been reports that some elm and maple trees in the state have fewer leaves than normal this spring. The likely reason is that several elms and maples produced an unusually large amount of seed this year, which trees do periodically. During a heavy seed production years, the tree will produce fewer leaves, which may make it appear sparse. Continue reading “Sparse-leafed elms and maples” →

Defoliation by June beetles

Posted on by jodieellis

By Mike Hillstrom, forest health specialist, Fitchburg. Michael.Hillstrom@wisconsin.gov; (608) 513-7690

June beetles defoliating an oak sapling at night.

June beetles defoliating an oak sapling at night.

June beetles (also called May beetles) are defoliating oak, aspen and birch trees in several parts of Wisconsin this spring. These beetles are unusual in that they feed on foliage at night – look for defoliation during daytime hours although no insects are present. Although the highest densities of June beetles have been found in Crawford and Grant counties in southwest Wisconsin, forest health staff has also received reports of the insect from northeast and west central Wisconsin. Continue reading “Defoliation by June beetles” →

Forestry partners take lead in 2018 EAB trapping

Posted on by jodieellis

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.

Areas of possible initial EAB emergence.

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” →

Eastern tent caterpillar and control options

Posted on by jodieellis

By Linda Williams, forest health specialist, Woodruff. Linda.Williams@wisconsin.gov; 715-356-5211 x232

Young eastern tent caterpillars on their web nest. Photo: Linda Williams

Young eastern tent caterpillars on their web nest. Photo: Linda Williams

Winter is finally over and eastern tent caterpillars are hatching and building their web nests! In northern Wisconsin, the caterpillars began hatching in early to mid-May, but they emerged earlier in southern Wisconsin. Webs will become larger as the caterpillars feed and grow. Continue reading “Eastern tent caterpillar and control options” →

Forest tent caterpillar: surveys, prediction, and history

Posted on by jodieellis

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

Areas in northern Wisconsin with forest tent caterpillar defoliation during the peak year of most recent regionwide outbreak, from 1999 – 2002

Forest tent caterpillar larvae feeding on ash foliage. Photo: Paul Cigan

Late-winter surveys in northern Wisconsin for egg masses of forest tent caterpillars (FTC) suggest that numbers will remain low through 2018, continuing a 15-year trend, one of the longest documented intervals between FTC outbreaks in the state. Continue reading “Forest tent caterpillar: surveys, prediction, and history” →

Trapping for non-native beetles

Posted on by jodieellis

By Mike Hillstrom, forest health specialist, Fitchburg. Michael.hillstrom@wisconsin.gov; (608) 513-7690

A Lindgren funnel trap hung to collect beetles near Green Bay, WI. Photo: Mike Hillstrom

Scott Schumacher, an insect trapper for the Wisconsin DNR’s forest health team, will spend this summer hunting for non-native beetles using funds provided by the U.S. Forest Service. The survey is particularly focused on non-native bark and ambrosia beetles, which are potentially harmful to Wisconsin forests. In early May, Schumacher hung Lindgren funnel traps at 12 sites in Wisconsin which he will be checking throughout the season. Traps were placed at high-risk sites in wooded areas near large commercial port entries on Lake Michigan and near pallet and other waste-packaging recycling companies. Although preventing the arrival of non-native species is always top priority, early detection and rapid response (EDRR) to newly-detected infestations is an important strategy to protect forests from damaging invaders.

Ladybugs in your house this spring?

Posted on by jodieellis

By Linda Williams, forest health specialist, Woodruff. Linda.Williams@wisconsin.gov; 715-356-5211 x232

One option for removal of ladybugs from your home is to flick them into a small container containing soapy water, which will kill them.

One option for removal of ladybugs from your home is to flick them into a small container containing soapy water, which will kill them. Photo: Linda Williams

In the December 2017 edition of Forest Health News, I wrote about ladybugs congregating in or on homes during autumn. Now that winter has finally ended in Wisconsin, ladybugs that spent winter in the walls of your house are emerging, and many of those will accidentally emerge into, not out of, your home. This can create panic or aggravation, depending on you (or your spouse’s) tolerance for insects in the house. Continue reading “Ladybugs in your house this spring?” →

Defoliation by larch casebearers

Posted on by jodieellis

By Linda Williams, forest health specialist, Woodruff, (Linda.Williams@wisconsin.gov), 715-356-5211 x232

The two cigar-shaped, tan objects sticking to the newly expanding needles of this tamarack tree are larch casebearer caterpillars, feeding on the foliage.

The two cigar-shaped, tan objects sticking to the newly expanding needles of this tamarack tree are larch casebearer caterpillars, feeding on the foliage. Photo: Linda Williams

As tamarack needles begin to appear, so do some tiny caterpillars that feed on them. Larch casebearers defoliate tamarack trees early in the season, first causing the trees to look pale green or yellowish, or even brown if defoliation is severe. This year I have been able to find larch casebearers wherever I look, but so far, I haven’t found any high populations of the insect. Continue reading “Defoliation by larch casebearers” →

Tree mortality in low areas

Posted on by jodieellis
Trees have grown in this low area for many years, but high-water levels and constant rainfall in 2017 was too much for them. The larger trees have already died, and the small white pine are not doing well at all.

Trees have grown in this low area for many years, but high-water levels and constant rainfall in 2017 was too much for them. The larger trees have already died, and the small white pine are not doing well at all. Photo: Linda Williams

By Linda Williams, forest health specialist, Woodruff. Linda.Williams@wisconsin.gov; 715-356-5211 x232

I continue to get calls about dying trees that are a direct result of all the rainfall we got throughout last year’s growing season. When the ground is saturated so many times throughout the growing season as we saw last year, trees are put under significant stress. Even trees that typically grow well in seasonally wet areas may not do well when the ground is wet for extended periods. Under these conditions, roots start to die due to lack of oxygen, and the crown of the tree will also die back.  Continue reading “Tree mortality in low areas” →

Region-wide needle tip browning on red pine

Posted on by jodieellis
Typical appearance of needle tip browning on lower portion of red pine crowns

Red pine with needle tip browning on the lower crown. Photo: Paul Cigan

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

Although no tree mortality is associated with the condition, widespread needle tip browning on red pine has been observed for the second consecutive year across much of the upper Great Lakes region. The condition is heavier in some places than others, but once in a stand or location, tends to be evenly distributed. Needle tip browning is common on the lower half of mature red pine crowns. On two- to three-year-old needles, the outer half to three-quarters of the needles appear reddish brown to straw-colored while needle bases remain green. Black or dark brown necrotic bands and spots are often present on symptomatic needle tips. Lower crown thinning is also common on symptomatic pine. Newly impacted needles will gradually lighten in color from reddish brown to straw-colored as dead needle tips dry out through the growing season. Continue reading “Region-wide needle tip browning on red pine” →