Wtsconsin Forest Health Highlights - December 1, 1998 ~
The Forest Health Protection Unit and Regional
Forest Pest Specialists provided a wide variety of
programs and information on forest pests, and
continued to teach ·integrated pest management
principles to DNR foresters, industrial foresters,
and private woodland owners. They successfully
educated about 4,500 individuals at 79 different
training sessions. At the same time, insect and
disease detection surveys were conducted on
approximately 9.6 million acres, and evaluation
surveys on 1.8 million acres.
!The Resource
The area of forest land in Wisconsin has been
steadily increasing in recent decades and
currently stands at almost 16.0 million acres,
representing 46 percent of the total land area.
The state now has the most forest land than it has
had at any time since the first forest inventory in
1936. Wisconsin's forests are predominately
hardwoods, with 84 percent of the total
timberland area classified as hardwood forest
t,pes. The primary hardwood forest type in the
state is maple-basswood, which makes up 5.3
million acres (34%) of Wisconsin's timberland
area. Conifer types represent 16 percent of the
total timberland area (pine forests - 8%, spruce­
fir- 6%, and swamp conifers- 2%).
Forests are important to the economy of
Wisconsin, not only in the form of wood
products, but also in the form of recreation and
tourism. The primary and secondary wood
products industry is the second largest employer
in the state and puts Wisconsin first in the nation
in the production of fine paper, sanitary paper
products, children's furniture, and millwork. The
value ofshipment of these products annually
exceeds $19.7 billion. Forest and water
resources in Wisconsin are a primary tourism
attraction for both residents and visitors. The
variety ofWisconsin's forest ecosystems support
a great diversity of wildlife species, while
recreational use of the forests continues to grow
and expand.
!Special Issues
This year, the gypsy moth spray program treated
61 sites, for a total of34, 711 acres in 20
counties. The bacterial insecticide, Btk was
applied twice, at one-week intervals, to all sites
in mid May. The majority of the acreage sprayed
was in Portage, Wood, and Waushara counties.
In late June, two more sites in Jefferson and Sauk
counties were treated to slow the spread of the
gypsy moth. Instead ofBtk, however, flakes
containing the female pheromone were
distributed by plane over parts ofDevil's Lake
State Park and the Southern Unit of Kettle
Moraine State Park.
Results from this year's trapping season revealed
a total of I 08,704 moths trapped from
approximately 45,000 delta traps throughout the
state. The total number of moths caught is a
reflection ofboth DATCP and cooperator data.
1998 Wisconsin Gypsy Moth Trapping Results
(WI Dept. of Agriculture, Trade, and Consumer Protection)
Introductions of biological controls for gypsy
moth, made in October 1997, were followed up
this summer. The fungus Entomophaga
maimaiga was introduced into 22 sites in eastern
WI. It has been confirmed that E. maimaiga has
become established at an introduction site in
Oconto, WI. At three sites in northeastern WI,
the parasitic wasp Cotesia melanoscela was
released.
No change was observed in the county
distribution of oak wilt in 1998. Surveys were
conducted in northeastern Wisconsin in
Marathon, Marinette, Menominee, and Shawano
counties. No significant movement north was
noted but new pockets in all of these counties
were observed. On a similar note, oak twig
girdler was widespread on northern pin oak and
black oak in Northwest and Central Wisconsin
this August. Damage from this pest was often
confused for oak wilt symptoms. The jumping
oak gall caused injury to buds of burr oak and
white oak in Southern Wisconsin in May. Trees
failed to leaf out in late May and early June, but
did refoliate two to three weeks later.
The fourth year of a five-year survey of oak wilt
was conducted to determine the relationship
between pruning of oak conducted by Allient
(formally Wisconsin Power & Light) and the
overland spread of oak wilt. Surveys were
concentrated in Columbia County. This project
will continue in 1999 and a summary report will
be written at the survey's conclusion.
County distribution of oak wilt in Wisconsin, 1998.
Efforts in 1998 concentrated on sampling
basswood for various insect pests. Data was also
collected on crown health, and the presence of
any other damaging agents were noted. This
project will continue through 1999 and possible
through the year 2000. Introduced basswood
thrips caused moderate defoliation in
Northwestern Wisconsin in 1998. Damage
covered approximately 9,700 acres in Bayfield,
Polk, Rusk, Sawyer, and Washburn counties.
Efforts on butternut canker continued to be
focused on collection of scion wood from
potentially disease resistant butternuts. Scions
were collected from a stand in Rock County and
one in Winnebago County. Scions were sent to
the USDA Forest Service for grafting to the root
stock of black walnut seedlings. Seedlings were
planted into orchards in MN and WI and will be
tested for their ability to resist infection.
A committee entitled Oak Wilt Management in
Communities, composed of private citizens and
individuals in local and state government and
private business worked together to create a
model ordinance for oak wilt control. Copies of
the model ordinance will be available in 1999
through DNR urban forestry specialists and
forest health specialists. The committee is also
developing a web site for oak wilt, which will be
maintained by the USDA Forest Service.
On May 31, a "derecho" or widespread, straight­
line wind event moved through parts of
southcentral and southeast Wisconsin - the most
damaging straight-line wind event to hit
Wisconsin in 100 years. Hurricane-like winds,
with gusts up to 100 mph, ripped through 12
counties in that part of the state. Thousands of
large trees were uprooted, twisted, broken off,
and downed by the winds.
A cooperative project between the USDA Forest
Service, University of Wisconsin and WI, MI
and MN DNRs was initiated to determine the
current health status of basswood in selected
areas of the state. The project was initiated in
response to an observed change in the crown
density and dieback of basswood in Michigan.
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Again, on June 27, high winds ripped through
Monroe, Trempealeau, and Jackson counties,
damaging nearly 100,00 acres of forested land.
About 3,000 acres of previously thinned red pine
plantations were snapped off, flattened, or bent.
Oaks and other hardwoods were tipped or broken
off. Cleanup and salvage operations began in
July and DNR foresters still continue to deal with
the storm damage. The Ips bark beetle moved in
rapidly and attacked damaged pines in early July.
ALB. Currently, no infestation on trees in
Wisconsin has been reported, although the beetle
could pose a serious threat since many Asian
goods are coming into Wisconsin.
Unlike most native long-horned beetles, Asian
long-horned beetles can attack and kill healthy,
mature hardwood trees. Known hosts are maple
(especially silver and Norway maples), boxelder,
horsechestnut, willow, poplar, birch, rose of
Sharon, and ash. At this point, the control
strategy in Wisconsin is to conduct a thorough
search for symptoms, but to avoid disturbing
adult beetles, which might cause them to
disperse. Trees with symptoms will be cut,
chipped, and burned during the dormant season.
IOther Issues
The Columbian timber beetle was found· in
Dane County on bur oak in September 1998.
While it may have previously existed here at low
numbers, it has never been recorded in
Wisconsin before.
It attacks a variety of
hardwood species, especially silver and red
maple and oak in some areas. Damage is limited
to the staining of wood in characteristic patterns,
which causes a reduction in the grade of
hardwood lumber. Gallery entrances heal over
and decay fungi seldom enter. Because the
beetle attacks healthy trees, mortality is seldom
associated with outbreaks.
A recently discovered pitch midge on white pine
Christmas trees has the potential to become a
pest, but the severity of the problem in
Wisconsin is not predictable. This white pine
pitch midge is native to North America and has
probably been in Wisconsin all along, but never
numerous enough to be noticed. The biology and
potential damage of this pitch midge is largely
unknown. They appear to inhabit pitch masses
that ooze from wounds caused by physical
damage. It is unclear whether they can initiate a
wound or if they cause increased pitch flow in
existing wounds. Currently, the only confirmed
location of white pine pitch midge in Wisconsin
is in Jackson County.
The lesser maple spanworm, which defoliates
red maple in late spring, occurs in the eastern
United States and Canada. This inchworm is
native to Wisconsin, but before 1998 it had not
been reported to cause noticeable defoliation.
This year in Sauk County, understory saplings
were often completely defoliated, while mature
trees were lightly to heavily defoliated. The
defoliation pattern was spotty, with individual
trees heavily defoliated and adjacent trees nearly
untouched. Pockets of heavily defoliated trees
often occurred near the center of the outbreak
area between Plain and Natural Bridge State
Park.
Various broadleaf defoliators were observed in
Northern Wisconsin in 1998. Aspen blotch
miner caused moderate to severe damage in
Langlade, Lincoln, and Oneida counties. Oak
webworm defoliated 2,000 acres of oak in the
Minong area in Washburn County, as well as in
Oneida County. Trembling aspen was severely
defoliated by large aspen tortrix in Oneida
County. For the first time in several years, bruce
span worm defoliated sugar maple in Florence
and Forest counties. The only previous outbreak
in Wisconsin occurred from 1984-1987 in the
same area - little maple damage resulted.
Asian long-horned beetle (ALB) infestations
have recently been reported in Illinois, and have
generated considerable interest in Wisconsin.
Three locations have been quarantined in the
Chicago area since the first infestation was
reported in early July. USDA- APHIS suspects
that the beetles were transported from Asia in
shipments that use wooden crates and pallets. In
southern Wisconsin, a beetle found inside a
warehouse three years ago was identified as
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IRegional Issues
Marathon County, pine spittlebug on jack and
red pines in Oneida and Vilas counties, and red
pine needle midge present on 1,500 acres in
Burnett and Washburn counties.
Efforts to detect changes in forest health on a
regional (Lake States) basis continues through
data collection on permanent plots- 89 for Forest
health Monitoring (FHM) and 18 for North
American Maple Project (NAMP). In addition to
visiting all plots on the ground, all 18 NAMP
plots were observed from the air in an attempt to
detect major outbreaks of spring defoliators. No
widespread defoliation of sugar maple was
detected on these plots in 1998. Data for both of
these plot programs centers on monitoring crown
conditions, including dieback, foliage
transparency, and crown density.
Due to the mild winter, followed by the long
growing season this year, there was an abundance
of multicolored Asian lady beetles throughout
the state. This swarm resulted in numerous calls
about the beetles invading homes.
A survey of white pine in Wisconsin is currently
underway to document the incidence of stem
cankers due to white pine blister rust. The
study focuses on pole and small sawtimber stands
in Risk Zone 4 of Northern Wisconsin. The main
objective is to evaluate the current status of older
stands that may have undergone high infection as
seedlings/saplings.
The regional forest entomologist in Green Bay
remains vacant. Plans are under way to fill the
position as soon as possible.
Northern Region
Kyoko Shimizu, Forest Pathologist
Rhinelander 715-365-8934
Shane Weber, Forest Entomologist
Spooner 715-635-4156
Wisconsin DNR Forest Health Protection Staff
Northeast Region
Vacant Position
Green Bay
South Central/Southeast Region
Dave Hall, Forest Entomologist
Madison 608-275-3275
West Central Region
Todd Lanigan, Forest Entomologist
Eau Claire 715-839-1632
Statewide
Jane Cummings Carlson, Forest Pathologist
Madison 608-275-3273
Andrea Diss, Gypsy Moth Coord
Madison 608-264-9247
Dave Hall, Forest Entomologist
Madison 608-275-3275
Allen Prey, Forest Health Protection Coord.
Madison 608-275-3274
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