Forests comprise 53% of the land area of the state, or about 19.3 million acres. These 

forests are a critical component of Michigan’s environment and economy for the 

recreational opportunities and the products they provide. Forestry related industries and 

manufacturing employ 150,000 people statewide and annually contribute $9 billion to 

the state’s economy. Additionally, forest-based tourism and recreation support 50,000 

jobs and add $3 billion to Michigan’s economy. Michigan’s forests contribute to clean 

air, water, and reduce soil erosion. 

We continue to find remote, outlying emerald ash borer (EAB) populations in Michigan. 

These outliers mostly represent pre-quarantine (e.g. year 2002 and earlier) spread of EAB. 

The 2005 EAB detection at Brimley was the first in Michigan’s Upper Peninsula. The 

Michigan Department of Agriculture (MDA) and Michigan Department of Natural 

Resource (DNR) acted quickly the remove this population. All ash greater than one inch 

in diameter were removed within 1⁄2 mile of infested trees and burned. This was a 2002 

introduction at Brimley State Park. It does not reflect on quarantine efforts to stop EAB at 

the Mackinac Bridge or DNR efforts banning the movement of ash onto state and 

federal lands, both of which began in 2005. No other EAB outliers have been detected 

in the Upper Peninsula. 

New EAB detections are the result of statewide trap tree surveys by the MDA and 

Michigan Technological University (MTU). The MTU survey is sponsored by the USDA Forest 

Service. Many of the new 2005 detections in Northern Lower Michigan and the one in 

the Upper Peninsula resulted from the MTU risk based survey. Risk was defined using maps 

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of the state’s ash resources and state park databases showing visits from residents of EAB 

infested counties. Trap trees were deployed in 135 high risk state and federal parks and 

campgrounds throughout Michigan and northern Wisconsin. The survey effort also 

included visual inspections of firewood and ash trees in these and adjacent areas. For 

more info visit: 

http://www.emeraldashborer.org 

The MDA EAB quarantine was revised on October 31, 2005. The quarantine includes 21 

quarantined counties in the southeast Michigan and 31 outliers with quarantine 

boundaries defined by townships which buffer remote EAB sites. All counties in the Lower 

Peninsula are either quarantined or regulated. No hardwood firewood or ash trees parts 

or products can move from quarantined areas or out of the Lower Peninsula without 

MDA inspection and approval. Visit the MDA website for specific quarantine language 

and updates at: 

http://www.michigan.gov/mda 

Beginning in the fall of 2004, the DNR conducts firewood sweeps in December after 

closure of the firearm deer hunting season. All hardwood firewood left at State Forest 

Campgrounds & State Parks is burned. 

The Forest, Mineral and Fire Management Division (FMFM) of the DNR adopted ash 

management guidelines for use on state lands. Accelerated commercial harvests will be 

used to remove ash on state lands within 1⁄2 mile of EAB outliers. Harvest of ash resources 

within 5 miles of EAB populations will be high priority. Conventional forest management 

practices will be employed to increase tree species diversity and decrease ash 

components where ash comprises a “significant” component of the forest resource. This 

harvesting reduces but doesn’t eliminate ash. Once EAB reaches stands managed with 

these guidelines, lower ash densities will reduce EAB impacts, and allow the harvest / 

salvage of remaining merchantable ash with less risk of creating under-stocked stands. 

The DNR awarded $521,332 in grants (USDA Forest Service Funds) to 39 Michigan 

communities and non-profit organizations for tree planting projects. This grant program 

helps communities replace EAB killed ash. Affected communities and non-profit 

organizations within the original 20 emerald ash borer quarantined counties and past 

outlier communities were eligible for financial and technical assistance in support of tree 

planting projects. This is the third round of tree planting grant assistance. 

The USDA Forest Service funded Rural Ash Monitoring Plot System was initiated during 

summer of 2004. This project is collaboration between the University of Michigan and 

MTU. A total of 400 forest health monitoring plots were established in stands containing 

ash throughout Michigan. The objective is to detect EAB presence in Michigan’s rural 

ash containing forests and to monitor current conditions and changes over time. This 

effort will provide baseline data to evaluate EAB induced forest resources impacts. 

Understanding of EAB population and host interactions is used to generate an EAB risk 

model. The model is used to create maps which direct and prioritize survey and 

management activities. 

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With assistance from USDA APHIS and the Michigan Department of Agriculture, an ash 

damage survey was conducted in late 2004 to assess impacts of EAB. The objective was 

to determine the relative impacts of EAB in and around the original core counties. 

Subsequent damage assessments will use remote sensed imagery and ground data to 

determine ash trees per acre and volume of ash affected, and provide information 

about the amount of ash in urban landscapes. 

The demand for hazard tree training has greatly increased. Personnel managing state 

parks and state forest campgrounds are facing new challenges due to EAB induced ash 

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morality in SE Michigan, and the spread of beech bark disease. Recognizing and 

removing hazardous trees is very costly as are tree and landscape restoration activities. 

Regulating the movement of firewood by the general public from infested areas remains 

the most difficult of tasks. The message: DON’T MOVE FIREWOOD! 

Visit the following websites for updates on EAB management, surveys and research: 

http://www.emeraldashborer.info 

http://www.na.fs.fed.us/fhp/eab/mgmt/mgmt.shtm 

Black Ash Decline and Mortality continues to be common in many parts of the state. This 

is related to past drought conditions. Trees growing in wet soils, such as black ash, often 

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suffer during droughts. Wetland trees tend to develop shallow root systems that cannot 

cope with a prolonged drop in soil moisture. Rising water tables after a prolonged 

drought may also drown deeper roots developed as the tree sought moisture during the 

drought years. 

A White Ash Root Rot is causing extensive wind throw of mature ash in high quality 

northern hardwood stands in Northern Lower Michigan. Stresses from overstocking may 

be involved. University and USDA Forest Service forest pathologists and entomologists 

visited ash decline areas in Northern Lower Michigan. Ash yellows was diagnosed as one 

of the causal agents of decline. Armillaria and other root pathogens are also involved. 

Further study based on these finding will follow. Understanding ash health is paramount 

in understand ash resource susceptibility to EAB. 

A Hemlock Woolly Adelgid quarantine continues to 

restrict movement of eastern hemlock into Michigan 

from infested counties of other states. All eastern 

hemlock shipments require a phytosanitary 

certificate. This follows the interception of the insect 

at two Michigan nurseries in 2000. 

Hemlock woolly adelgid, which is dispersed by wind 

and by movement of infested firewood, feeds on tree 

sap, killing needles, twigs and branches. Infested tree 

eventually die. 

Rapid early detection surveys for the adelgid were conducted statewide for the fourth 

straight year in hemlock stands and in areas adjacent to nurseries. This is part of a Forest 

Health Monitoring Evaluation Monitoring project. No adelgids were found in 2005. 

From the Michigan Department of Agriculture: Two recent interceptions of Hemlock 

Woolly Adelgid (HWA) on nursery stock and an increase in quarantine violations elicited 

a large scale survey and information gathering program in 2005. A total of 6,387 

hemlocks were inspected at 196 nurseries statewide between May and October. Firms 

were also queried regarding the sources of HWA nursery stock and sizes and dates of 

shipments. One hundred and seven trees were rejected for quarantine violations and 

several hundred were restricted pending proper certification. In addition, 877 hemlocks 

were inspected at 46 native stands in the Upper Peninsula and Northern Lower Peninsula 

during the same period. In total, over 7,200 hemlocks were inspected in 62 of Michigan’s 

83 counties. No hemlock woolly adelgids were detected. 

Beech Bark Disease (BBD) continues to threaten Michigan’s American beech resource. 

Beech is a component of 7.2 million acres of Maple-Beech-Birch type. This represents 138 

million beech trees in all size classes. Of these, 15 million larger beech (greater than 9­

inch diameter) are highly vulnerable to tree mortality. BBD is presently killing beech trees 

in areas infested with beech scale for 10 years or more. Many hundreds of acres of 

American beech are being harvested in the killing front areas of the eastern Upper 

Peninsula. 

The USDA Forest Service Research Facility in Delaware, Ohio continues to collect scions 

from Michigan’s resistant trees to study Beech Bark Disease Resistance. Scions from 

resistant American beech were again collected in December, 2005 and sent to the 

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Delaware, OH USFS research facility. Michigan has also agreed to host 1 or 2 seed 

orchards for propagating resistant seed beginning in the fall, 2006. 

The University of Michigan continues to expand the Beech Bark Disease Monitoring & 

Impact Analysis System plot network. Data collected for the BBDMIAS and also field 

observations during summer 2005 revealed new beech scale infestations in several areas. 

Counties in the Lower Peninsula that had new or increasing infestations include Antrim, 

Emmet, Leelanau, Manistee, Newaygo, Otsego and Wexford Counties. In addition, field 

crews observed very light scale populations in Cheboygan County and on Bois Blanc 

Island. 

Using data from the BBDMIAS, an effort was begun in 

2004 to calculate the current and projected spread 

of beech bark disease in Michigan. The goal is to 

develop a model based on empirical data to 

predict how rapidly beech scale and beech bark 

disease will spread through Michigan and to 

determine if spread rates in Michigan are consistent 

with estimates from other regions of North America. 

To date it appears the spread rate of beech scale in 

Michigan is about double that published for the 

Northeast, or about 10-15 miles per year. Spread 

rates will vary from stand to stand since the beech 

resource in the Lower Peninsula is much more 

fragmented than the Upper Peninsula. It believed 

that the beech scale in the Upper Peninsula was 

already widely distributed before the initial detection 

in 2000. 

Most of Chippewa, Luce and Mackinac Counties are now included in the advancing 

front and several new areas of infestation were found west of the previous boundary, 

primarily in Schoolcraft and Alger 

Counties. Beech scale in a plot 

on Drummond Island was 

reported as having light scale but 

has not been confirmed. 

On a positive note, mortality did 

not increase as dramatically as 

scale populations and most areas 

are still in the early stages of scale 

infestation. The most dramatic 

increase in beech mortality was in 

Tahquamenon Falls State Park on 

the Chippewa/Luce County 

border where over 90% of the 

beech overstory is either dead or 

severely declining. 

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Oak Wilt continues to spread naturally and artificially through much of the Lower 

Peninsula and in the south central Upper Peninsula. Movement of oak wilt on firewood is 

plaguing efforts to slow the spread of this fatal oak disease. 

To slow the overland spread of oak wilt, harvesting 

restrictions are observed on state land. Harvesting 

activities in forests where red oak trees remain 

after harvest cannot be cut between April 15 and 

July 15. Sap-feeding beetles responsible for 

spreading oak wilt are most active during this time. 

These small (1/4-inch long) beetles can pick up 

spores from diseased trees and transmit them to 

oak trees that have been damaged during 

logging operations. 

US Forest Service Oak Wilt Suppression funds for 

detecting and treating oak wilt epicenters in 

Michigan’s Upper Peninsula were not available in 

2005. However, detection efforts and landowners 

contacts continued in efforts to rid the Upper 

Peninsula of this threat to its oak resources. 

For information about identifying and preventing 

oak wilt, visit: 

http://www.extension.bpp.msu.edu/oakwilt2.pdf 

Sudden Oak Death (now known as Ramorum Blight) (Phytophthora ramorum [SOD]) has 

not been detected in Michigan’s nurseries, urban forests or forest lands. 

The Michigan Department of Agriculture participated in the National Ramorum Blight 

Nursery Survey again in 2005. Surveys were conducted at 33 production nurseries known 

or suspected of receiving nursery stock from infested areas of California, Oregon, 

Washington, and/or British Columbia. A total of 758 plants were sampled. Three samples 

are being processed as suspected P. ramorum. Since 2004, nearly 3,000 samples have 

been taken throughout the Lower Peninsula. No P. 

ramorum has been detected to date. 

Eastern Larch Beetle, Dendroctonus simplex, 

populations in Eastern and the South Central Upper 

Peninsula caused 25,717 acres of mortality in 2005. 

This bark beetle became epidemic in tamarack 

(Larix laricina) stressed trees from the drought of 

2000-2001 and repeated defoliation by the Larch 

Casebearer (Coleophora laricella). The casebearer 

is an introduced needle-mining insect. While 

populations are usually brought under control within 

2 years by parasite natural enemies, repeated 

heavy defoliation can cause branch dieback or 

tree mortality. 

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Spruce Budworm was defoliated 

9471 acres in several counties in 

Michigan’s Upper Peninsula. Areas 

of light budworm defoliation have 

been visible for the last few years. 

Areas of mature to over mature 

spruce/fir in the south central 

Upper Peninsula (south western 

Menominee County) have top kill 

and tree mortality caused by 

repeated defoliations. 

The Michigan Invasive Plant 

Council strives to increase 

awareness, education and 

management of invasive plants. 

Scots Pine (Pinus sylvestris) is 

systematically being removed from state forestlands. Prescribed fire is one tool being 

tried to reduce Spotted Knapweed (Centaurea maculosa) populations in oak savannas 

in the south central Upper Peninsula., Cluster head pink (Dianthus carthusianorum) was 

detected in the Upper Peninsula and with efforts to eradicate planned in 2006. Common 

buckthorn (Rhamnus cathartica) plagues many areas of the state. The Seney Wildlife 

Refuge continues to battle buckthorn populations with herbicides and prescribed fire. 

Garlic Mustard (Alliaria petiolata) monitoring, management and eradication projects are 

gaining momentum in Michigan. Public and private organizations are cooperating in 

efforts to remove and keep garlic mustard from establishing in new areas of Upper 

Michigan and the Northwest Lower Peninsula. A seventy acre northern hardwoods site in 

the Eastern Upper Peninsula has a seven year prescribed burn plan which includes 

follow-up use of glyphosate herbicide to treat plants missed by fire. Treatments are 

designed to contain the spread of the plant and eventually eliminate garlic mustard. 

Additional monitoring of plant community response to burning and herbicide treatments 

is planned for 2006. 

Giant-hogweed Heracleum 

mantegazzianum) has been found in 11 

Michigan counties. First discovered in 2001, 

Giant Hogweed has now been confirmed in 

the following counties: Branch, Calhoun, 

Gogebic, Ingham, Jackson, Kalamazoo, 

Kent, Manistee, Oakland, Ottawa and 

Saginaw. 

Only a few small scattered pockets of aspen 

and oak defoliation remain as evidence of 

the large scale Forest Tent Caterpillar (FTC) 

(Malacosoma disstria) epidemic which 

began in 2000. 

The Red-Headed Pine Sawfly (Neodiprion 

lecontei) periodically defoliates young red 

and jack pine. Sawfly populations have 

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been active in the eastern Upper Peninsula and the northern Lower Peninsula beginning 

in 2002. Dimlin 4L was aerially applied to 480 acres of infested plantation red pine in 

2005. 

For information about identifying and controlling redheaded pine sawfly, visit: 

http://www.na.fs.fed.us/spfo/pubs/fidls/pine_sawfly/pinesawfly.htm 

Gypsy moth (Lymantria dispar) defoliated 148,525 acres of oak forests statewide in 2005, 

up from 45,244 acres in 2004. A warm, dry spring did not favor Entomophaga 

development, so overall state 

populations of gypsy moth will 

likely increase in 2006. 

According to a Michigan 

Department of Agriculture report 

a total of 4,316 acres in six 

counties in the Lower Peninsula 

were treated as part of the 

Cooperative Gypsy Moth 

Suppression Program in 2005. This 

was a significantly smaller 

acreage than 2004, when 24,581 

acres were treated in 11 counties, 

and represents the second 

smallest treatment acreage since 

the program’s inception in the 

1980’s. 

The Jack pine budworm (Choristoneura pinus pinus) 

is considered the most significant pest of jack pine. 

Stands older than 50 years are vulnerable to 

damage. Jack pine over 50 years old that has 

suffered 2 or more defoliations during the past 3 

years is at highest risk of top kill or mortality. Tree 

mortality and top-kill resulting from budworm 

defoliation creates fuel for intense wildfires. 

Harvesting stands when they reach maturity can 

minimize budworm-caused tree mortality and 

reduce the threat of damaging wildfires. 

The current jack pine budworm epidemic defoliated 

201,470 acres this year and has spread to many jack 

pine areas of the Upper Peninsula. Student assistants 

were used to assess budworm impacts on high risk 

stands. Based on these impact surveys many stands 

are being salvaged and pre-salvaged. Other stands 

were targeted for 2006 evaluation. 

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 High risk stands were also recommended for harvest in the Northern Lower Peninsula 

based on stand vulnerability budworm damage and defoliation surveys. Budworm 

populations in the Lower Peninsula are subsiding. 

Bugs on the Screen 

Maple Tar Spot was a common site on 

Norway maple leaves in 2005. Other 

maples are also infected. Fungi in the 

genus Rhytisma infect the leaves of 

maples causing the characteristic 

black spots to form on upper leaf 

surfaces. Heavy infections can cause 

early leaf drop in the fall. Black spots 

grow in diameter and thickness until 

late summer. 

in June were common in 2005. 

Although drought and other tree 

stressors also cause premature leaf 

drop, Maple Petiole Borers, 

Caulocampus acericaulis, were the 

culprit in most cases. These are a tiny 

non-stinging wasp called sawflies. 

Sawfly larvae feed in the petioles 

(stems) of maple leaves in the spring. 

Green leaves without most of their 

petiole litter the ground by late spring. 

This leaf loss is not considered a serious tree health threat. 

Research Update 

Dr. Gerard Adams, Michigan State University was contracted to map the spread of 

Dogwood Anthracnose in the Southern Lower Peninsula. Fifty GPS-positioned permanent 

impact plots were established in natural dogwood stands in 30 counties. The advancing 

front of the epidemic has spread to five additional counties in the last five years. To 

date, at least 11 counties in Michigan have become infested. The impacts reported in 

this study are of infestations impacting native forest stands, excluding additional counties 

where the pathogen infests only ornamental Cornus florida in private gardens and 

nurseries. 

Dr. Gerard Adams, Michigan State University was contracted to determine how to grow 

red and jack pine seedlings in Michigan which are free of Diplodia sapinea (a.k.a. 

Sphaeropsis sapinea). Red pine cones were purchased for seed to supply the future 

needs of DNR nursery plantings. These seed stores were evaluated by origin to determine 

availability of Diplodia free seed. Additionally, the encroachment of D. sapinea into 

clean stands will be monitored in future years to estimate rate of infestation over time. 

This should provide an estimate the durability of the non-infested nature of clean seed 

stock following out-planting. 

Reports of leaves dropping from maples 

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The North Central Region Risk Mapping Project expanded in 2004 to include states in the 

Northeastern and Southern Regions. This effort, begun in 2000 in cooperation with USFS 

State & Private Forestry and, beginning this year, the USFS Forest Health Technology 

Enterprise Team, brings together forest health and Geographic Information System (GIS) 

resources to design and produce forest insect and disease risk models. Multi-criterion 

modeling (MCM) is used to predict the risk of major forest types becoming infested by 

(susceptibility) and dying from (vulnerability) various native and exotic forest pests. MCM 

combines a variety of GIS data (criteria), including soil, tree, climate and forest health 

information, into detailed maps that will assist resource professionals in planning and 

conducting forest health management activities. 

For additional information about this project, see: 

http://www.fs.fed.us/foresthealth/mcm/ 

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For more information, contact: 

Bernie Hubbard 

MI Dept. of Natural Resources 

Forest Management Division 

525 West Allegan, 5th Floor 

Lansing, MI 48933 

517.335.0000 

Forest Health Protection 

Northeastern Area 

USDA Forest Service 

1992 Folwell Avenue 

St. Paul, MN 55108 

651.649.5261