1999 Annual Northeastern Area

Forest Health Protection Insect and Disease Conditions Report

 

Prepared by USDA Forest Service, State and Private Forestry in

cooperation with State Forestry Agencies in the Northeastern Area"

 

 

Insects: Native

 

Balsam gall midge

Paradiplosis tumifex

 

Region 9/Northeastern Area: New Hampshire, Maine, Vermont

Host(s): Balsam fir

 

Populations exploded in 1999 and were moderate to high in many areas in Maine. Estimates of the area affected exceed 10,000 acres and it was difficult to find suitable balsam fir brush for wreaths. This created a problem when hundreds of shipped wreaths were rejected by states such as California. Scattered populations occurred in Maine and Vermont.

 

Balsam shoot boring sawfly

Pleroneura brunneicornis

 

Region 9/Northeastern Area: Maine

Host(s): Balsam fir, Frasier fir

 

Balsam shoot boring sawfly levels receded to normal in 1999 in Maine. Sawflies could be found in all locations where there was damage in 1998, but there was minimal damage this year.

 

Cherry scallop shell moth

Hydria prunivorata

 

Region 9/Northeastern Area: Vermont

Host(s): Beech, black cherry

 

            There was scattered, light damage reported in Vermont in 1999.

 

Eastern spruce budworm

Choristoneura fumiferana

 

Region 9/Northeastern Area: Maine, Michigan, Minnesota, Vermont

Host(s): Balsam fir, white spruce

 

In Maine, spruce budworm moth catch in both pheromone and light traps was the lowest since 1995. Lower catch in 1999 ended a three trend toward increased moth catch and more widespread distribution of the locations where budworm moths were trapped. No larvae were found and no defoliation was detected. There was no defoliation in Michigan in 1999. Significant defoliation occurred on forestlands in northeast Minnesota encompassing an area of 70,000 acres, down from 240,233 acres in 1998. This is the 46th consecutive year of spruce budworm defoliation in Minnesota. Populations remained low in Vermont and there was no defoliation in 1999.

 

Eastern tent caterpillar

Malacosoma americanum

 

Region 9/Northeastern Area: West Virginia

Host(s): Black cherry

 

Light to moderate defoliation was observed over most of West Virginia. Heavy defoliation was reported in Marshall County.

 

Eriophyid mites

 

Region 9/Northeastern Area: Pennsylvania

Host(s): Northern red oak

 

In northcentral Pennsylvania, 10,000 acres of mature northern red oak were defoliated by Eriophyid mites. It is believed that the drought played a key role in this outbreak.

 

Fall cankerworm

Alsophila pometaria

 

Region 9/Northeastern Area: Maine, Maryland, Massachusetts, West Virginia

Host(s): Maples, oaks, other hardwoods

 

In Maine, populations continued to decline, with light to moderate defoliation in Aroostook County. Scattered defoliation was reported in Charles and Prince Georges Counties, Maryland. In 1999, in Massachusetts, the fall cankerworm caused 2,457 acres of defoliation in Plymouth and Norfolk Counties. Based on reports of heavy male moth flight in these two counties, an increase in defoliation is expected in 2000. The 1998 populations in Pocahontas, Preston, and Monongahela Counties, West Virginia, apparently crashed in 1999. Defoliation was too light to record damage.

 

Fall webworm

Hyphantria cunea

 

Region 9/Northeastern Area: Maine, Vermont

Host(s): Apple, ash, beech, birch, cherry, elm, oak

 

Populations and damage by this species were extremely high in 1999, especially in southwestern Maine (Cumberland, York, and southern Oxford Counties). More than 10,000 acres were affected. Many trees were totally stripped and webbed by mid-August. Populations were high throughout Vermont.

 

Forest tent caterpillar

Malacosoma disstria

 

Region 9/Northeastern Area: Illinois, Maine, Minnesota, Michigan, Vermont, Wisconsin

Host(s): Aspen, basswood, pin oak, sweetgum, other hardwoods

 

Over 7,000 acres were defoliated in Illinois on the Shawnee National Forest.

In Maine, low and endemic populations were present in 1999 and no defoliation was observed. Defoliation occurred in Minnesota on nearly 500,000 acres in 1999, up from 11,217 acres in 1998. This year Michigan sustained defoliation on 163,000 acres, and in Wisconsin 47,000 acres were affected. Populations in Vermont remained low with no defoliation in 1999.

 

Hemlock looper

Lambdina fiscellaria

 

Region 9/Northeastern Area: Maine

Host(s): Balsam fir, eastern hemlock, white spruce

 

No damage or significant larval populations were reported in Maine in 1999, but sightings and coincidental trapping of hemlock looper moths were up sharply, with numerous reports of looper moth activity in the forests of east coastal, central, and northern Maine.

 

Jack pine budworm

Choristoneura pinus

 

Region 9/Northeastern Area: Maine, Michigan, Wisconsin

Host(s): Jack pine, red pine, white pine

 

In Maine, moth activity of this species seemed to increase in light traps in Mt. Vernon (Kennebec County) and Steuben (Washington County) in 1999, however no defoliation was observed. Primarily, white pine occurs near the Mt. Vernon trap site and Jack, red and white pine occur at the Steuben site. In 1999, 10,500 acres of defoliation were observed in Michigan. This was the third outbreak year for Jack pine budworm in Michigan. In Wisconsin, no defoliation was reported this year.

 

 

 

 

 

Jumping oak gall

Neuroterus saltatorius

 

Region 9/Northeastern Area: Indiana, Missouri

Host(s): Bur oak, white oak

 

About 1 million acres were affected in Indiana, mostly in the northern third of the state. Heavy damage from this gall-producing wasp was reported on trees in eastern and southeastern Missouri encompassing 612,000 acres. In addition, light damage was reported on 5 million acres extending from St. Louis to the Arkansas border. This was up from 1,883,900 acres in 1998. When galls become numerous they cause leaf discoloration or premature leaf drop. 

 

Large aspen tortrix

Choristoneura conflictana

 

Region 9/Northeastern Area: Maine, Michigan, Minnesota, New Hampshire, Vermont, Wisconsin

Host(s): Aspen

 

Scattered defoliation occurred across northern Maine in 1999, but most was light with localized moderate defoliation noted only around open farmland in eastern Aroostook County, with less than 100 acres affected. Moth numbers were down noticeably. The large aspen tortrix defoliated 382,382 acres in Upper Peninsula of Michigan in 1999, down from 592,121 acres in 1998. Defoliation caused by this insect also occurred on 340,000 acres in St. Louis County in Minnesota, up from 3,078 acres in 1998. In New Hampshire, there was light scattered defoliation. Populations in Vermont increased, however no defoliation was detected. In Wisconsin, 1,738 acres were defoliated.

 

Locust leafminer

Odontota dorsalis

 

Region 9/Northeastern Area: West Virginia

Host(s): Black locust

 

Locust leafminer was moderate to heavy in the most eastern and northern panhandle counties of West Virginia. Elsewhere in the State, defoliation was light to moderate. Defoliation was detected by mid-June this year, probably aggravated by drought.

 

 

 

 

 

 

 

Maple leafcutter

Paraclemensia acerifoliella

 

Region 9/Northeastern Area: Maine, Vermont

Host(s): Sugar maple

 

In Maine, populations and damage by this species seemed more diffused in 1999 than in 1998 and, although the acreage affected rose to roughly 500 acres, the damage level fell to light to moderate on all but a few acres. Defoliation was only noted in northern York County and a 25 acre area on Mount Desert Island (Hancock County). Populations in Vermont increased over 1998 levels.

 

Maple trumpet skeletonizer

Epinotia aceriella

 

Region 9/Northeastern Area: Vermont

Host(s): Sugar maple

 

            Damage was heavy in Vermont, although slightly down from 1998.

 

Oak leaftier

Croesia semipurpurana

 

Region 9/Northeastern Area: Maine, Pennsylvania, West Virginia

Host(s): Black oak, red oak, scarlet oak

 

Defoliation by a complex of the oak leaftier and oak skeletonizer, Bucculatrix ainsliella, was fairly widespread over 8,000 to10,000 acres across southern Maine in 1999. Most defoliation fell in the light to moderate category with about 500 acres of very spotty moderate to heavy. The defoliation occurred in Hancock, Knox, Lincoln, and Waldo Counties. In Potter and Tioga Counties in Pennsylvania, 3,786 acres were defoliated by oak leaftier. This was a twofold increase of defoliation from last year. Treatments of the most severely affected areas were conducted to prevent defoliation and mortality. In West Virginia, egg surveys were conducted in Barbour, Pendleton, Pocahontas, Randolph, and Tucker Counties but no eggs were found. Light populations were reported in Randolph, Pocahontas, Tucker and Pendleton Counties and defoliation was light and spotty. 

 

Oystershell scale

Lepidosaphes ulmi

 

Region 9 /Northeastern Area: Maine

Host(s): Beech

 

Populations increased in 1999 especially on beech in central Maine (central Penobscot and southern Piscataquis Counties). Moderate to high populations were observed locally where some branch mortality occurred. Mortality was probably accentuated by drought.

 

Periodical cicada

Magicicada septendecim, M. septendecula, M. cassini

 

Region 9/Northeastern Area: Maryland, Ohio, Pennsylvania, West Virginia

Host(s): Hardwoods

 

Three separate species of periodical cicadas appeared this spring over large portions of Ohio and West Virginia during the scheduled Brood V emergence. This Brood is the largest that occurs in either State and was last seen in 1982. It also emerged in the southwest corner of Pennsylvania and the western most county of Maryland. In West Virginia, over five million acres were mapped during emergence where flagging was visible.

 

Scarlet oak sawfly

Caliroa quercuscoccineae

 

Region 9/Northeastern Area: Ohio, West Virginia

Host(s): Black oak, pin oak, red oak

 

In Ohio, only 13 counties reported light defoliation compared to the 290,000 acres heavily defoliated in 1998. In West Virginia populations dramatically decreased from 186,000 acres defoliated in 1998 to only light defoliation in 1999. Counties infested were Clay, Marshall, and Wetzel Counties, West Virginia. 

 

Southern pine beetle

Dendroctonus frontalis

 

Region 9/Northeastern Area: Maryland

Host(s): Loblolly pine

 

Ground surveys detected a few spots of southern pine beetle activity on 19 acres in a State park located in Somerset County, Maryland.

 

Spruce beetle

Dendroctonus rufipennis

 

Region 9/Northeastern Area: Maine

Host(s): Red spruce, white spruce

 

The condition of many of Maine's coastal spruce stands continued a gradual decline in 1999. The current spruce beetle infestation remains confined predominantly to the central Maine coast, especially Penobscot Bay. The area infested by spruce beetle increased slightly, but the intensity of attack in infested stands appeared to decline. Several Penobscot Bay stands had lost more than 50 percent of all their red and white spruce over 15 inches in diameter. Four newly attacked stands were found in 1999 in the Cape Rosier area, Seal Harbor, Bass Harbor, and on islands near Vinalhaven. About 2,760 acres of 30 to 50 percent mortality and 465 acres of greater than 50 percent mortality were mapped. Drought conditions in 1999 are likely to add more stress to coastal spruce stands and may result in expansion of the spruce beetle infestation as was seen following the 1995 drought.

 

White pine weevil

Pissodes strobi

 

Region 9/Northeastern Area: Maine

Host(s): White pine

 

In Maine, this perennial problem continued to seriously limit the growth of white pine without treatment. Severe damage was noted again in 1999. The increased incidence of small tree mortality in recent years may also be drought associated.

 

Yellowheaded spruce sawfly

Pikonema alaskensis

 

Region 9/Northeastern Area: Maine

Host(s): Black spruce, white spruce

 

Yellowheaded spruce sawfly required control measures on 400 acres in western Maine in 1999. Scattered pockets of damage can still be found in western and northern Maine in Franklin, Somerset, Penobscot and Aroostook Counties.

 

 

Insects: Non-native

 

Asian longhorned beetle

Anoplophora glabripennis

 

Region 9/Northeastern Area: Illinois, New York

Host(s): Ash, birches, black locust, elm, horse chestnut, maples, poplar, willow

 

This insect, a serious pest of hardwoods in China, has been discovered in Chicago and New York City. There are currently three separate infested areas within the Chicago metropolitan area, along with other spot infestations. A new quarantine area was established in Chicago in 1999 called the “All Saints” infestation. Since the initial discovery, 1,243 trees have been cut, including 357 in 1999. In 1999, 1,498 trees were replanted in the infested areas. From 1996 to 1998, infestations in New York were found in Brooklyn (Greenpoint), Queens (Bayside), and the Amityville area of Long Island. Over 4300 trees have been found infested and 3966 trees have been removed. About 2000 trees have been replanted. Three new infestations were discovered in 1999: Bayside (669 trees have been removed), Manhattan, close to Central Park (23 trees have been removed), and Islip (7 trees removed). Intensive surveys for infested trees will be continued. Other states have also actively been surveying for the pest. Connecticut has been continually surveying around the harbors in Bridgeport, Groton, New Haven, and New London and all surveys were negative. Maryland initiated a survey of industrial and port areas statewide and no beetles were found. In New Jersey, 326 plots were surveyed and no beetles were found. The insect has been detected in wood packing material at warehouses in various other locations across the country.

 

Balsam woolly adelgid

Adelges piceae

 

Region 9/Northeastern Area: Maine

Host(s): Balsam fir

 

This introduced species is a perennial problem in Maine but has been a concern primarily of homeowners and landscapers. It continued to kill and deform fir in coastal areas from Brunswick to Calais. Infestations also plagued some Christmas tree growers and may become more serious if mild winters continue. In 1999, infestations of woodland fir were reported across southern Piscataquis and central Penobscot Counties. In at least two areas totaling 500 acres, these infestations were accompanied by bark beetle attack and mortality after only a couple of years.

 

Browntail moth

Euproctis chrysorrhoea

 

Region 9/Northeastern Area: Maine, Massachusetts

Host(s): Red oak

 

The browntail moth was located in 58 towns in Maine in 1999 during the annual winter survey, this is a slight reduction from 1998. Twenty-seven of these towns had sufficient population levels to represent a hazard to individual landowners. In the Casco Bay area, populations of this pest were again high enough to warrant control. Municipal spray programs were done on 5,120 acres in five towns. There was a shift in population from southern portions (Portland) to more northern sites (Freeport and Harpswell). The trend in year 2000 appears to be a continuance of damaging populations in the Casco Bay area and a depression of populations in outlying areas. Scattered populations continued on Cape Cod in Massachusetts.

 

 

 

 

 

 

 

Common European pine shoot beetle

Tomicus piniperda

 

Region 9/Northeastern Area: Indiana, Illinois, Maryland, Michigan, New Hampshire, New York, Ohio, Pennsylvania, Vermont, Wisconsin, West Virginia

Host(s): Scotch pine, white pine, pines

 

The pine shoot beetle is a pest of pine trees, which causes damage in weak and dying trees, and in the new growth of healthy trees. The beetle has been found in a variety of pine species in the United States and was first discovered this country in a Christmas tree farm in Ohio in 1992. In 1999, one county was added in Illinois (Woodford), and five new counties in Indiana (Hammilton, Henry, Rush, Marion, Montgomery). Eleven counties were surveyed in Maryland for pine shoot beetle and beetles were trapped in two counties, Garrett and Allegany. In 1999, The insect was trapped for the first time in New Hampshire in Coos County, however no trees were found infested. In New York in 1999, the common pine shoot beetle was found in seven new counties: Jefferson, Lewis, Oneida, Madison, Chenango, Broome, and Tioga. No new counties were added to the quarantine area of Ohio, where the quarantine remains at 54 counties. The beetle was found in Vermont in 1999, with nine beetles trapped in Essex County and one in Orleans County near the Canadian border. Other states have surveyed for the beetle. In Connecticut Christmas tree plantations, along with cut trees, were examined and no beetles were discovered.

 

European pine shoot moth

Rhyacionia buoliana

 

Region 9/Northeastern Area: Maine

Host(s): Jack pine

 

This species seems to be increasing in numbers and distribution in Maine. Several new infestations were spotted in 1999 on red pine affecting 100 acres primarily in Lincoln, Sagadahoc, Waldo, and extreme southern Penobscot Counties. Some tip mortality was noted.

 

Gypsy moth - European

Lymantria dispar

 

Region 9/Northeastern Area: Connecticut, Indiana, Maine, Maryland, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, Vermont, Wisconsin

Host(s): Apple, aspen, basswood, black walnut, northern red oak, pin oak, red oak, white oak.

 

During the aerial survey of 1.8 million acres of urban/suburban forest in all eight Connecticut counties, no gypsy moth defoliation was found. No defoliation occurred in Indiana where treatments in 1999 reduced moth catches from 81,000 in 1998 to 13,500 in 1999. Gypsy moth has been very scarce in recent years in Maine presumably due to mortality from the fungus Entomophaga maimaiga. No defoliation was found during summer aerial survey and egg mass levels have continued to be very low throughout the southern half of the State. No significant increase in the population level of this pest is expected in 2000 in Maine. In Maryland, scattered defoliation was reported in Baltimore, Cecil, Dorchester, Frederick, and Washington Counties on 1,197 acres. Gypsy Moth defoliated slightly over 9,800 acres this past season in Massachusetts, this figure is up slightly from 1998, possibly a result of the inactivity of the fungal pathogen, Entomophaga maimaiga. Gypsy moth populations decreased in Michigan, where defoliated acres went from 301,780 acres in 1998 to about 176,625 acres in 1999. In New Jersey, gypsy moth defoliated 1,380 acres in Burlington, Camden, and Salem Counties. In New York in 1999, 4000 acres in the town of Rochester, Ulster County were defoliated and 2000 acres in Warren, Washington, and Saratoga Counties had moderate-heavy defoliation. Gypsy moth populations increased most dramatically in Ohio, where defoliation soared from 1,261 acres in 1998 to 48,162 acres in 1999. Gypsy moth is also on the increase in Pennsylvania with 281,605 acres of defoliation reported statewide. Defoliation on Federal lands included 496 acres at Raystown Lake, Pennsylvania; one acre at Berlin Lake, Ohio; and 244 acres at Mosquito Creek Lake, Ohio. Cuyahoga Valley National Recreation Area, Ohio, reported moderate to heavy defoliation on 4,372 acres. Populations remained low in Vermont, with no defoliation detected. Wisconsin treated over 54,000 acres, but moth catches continued to increase to over 125,000, a new record for the State.

 

Hemlock woolly adelgid

Adelges tsugae

 

Region 9/Northeastern Area: Connecticut, Delaware, Maryland, Massachusetts, New Jersey, New York, Pennsylvania, Rhode Island, West Virginia

Host(s): Eastern hemlock

 

The hemlock woolly adelgid occurs in 164 of 169 towns in Connecticut, where all eight counties are infested. The hemlock woolly adelgid infestation expanded to one additional county (Allegheny) in Maryland and infestations are found in 50 percent of the counties in the state. Twenty-one new townships were identified has having infestations in Massachusetts in 1999, but no new counties were found to be infested. This brings the number of townships known to be infested to 88. Delaware Water Gap National Recreation Area, bordering Pennsylvania and New Jersey, reported 24 acres of hemlock mortality and 40 acres of discoloration and decline. Picatinny Arsenal, New Jersey, reported hemlock discoloration and decline on 148 acres. The spread of hemlock woolly adelgid throughout the 26,000 acres of hemlocks in northern New Jersey continues unchecked. Hemlock stands that just a year ago did not have any hemlock wooly adelgid are now heavily infested. In New York, the adelgid has been infesting hemlocks in the southeastern portion of the state, with a new county record in Greene County in 1999, indicating that the infestation is spreading north. Hemlock woolly adelgid continued to spread in Pennsylvania and 31 counties have confirmed infestations affecting both ornamental and forest hemlocks. In West Virginia, the 1999 survey located additional areas of infestation in Monroe, Pocahontas, and Greenbriar Counties. Defoliation and needle discoloration from hemlock woolly adelgid was particularly noticeable this year due to the additional stress the trees were under from the severe drought conditions experienced over most of the growing season. To date, eleven counties are infested with hemlock woolly adelgid in West Virginia. Release and evaluation of the hemlock woolly adelgid insect predator, Pseudoscymnus tsugae, were initiated in Connecticut, Massachusetts, Maryland, New Jersey, New York, Pennsylvania, Rhode Island, and West Virginia in May of 1999. Evaluation of predator impacts at the release sites are currently being evaluated. 

 

Pear trips

Taeniothrips inconsequens

 

Region 9/Northeastern Area: Maine, Massachusetts, Vermont

Host(s): Red maple, sugar maple

 

In Maine, populations remained low and spotty in 1999. Leaf tattering and defoliation caused by pear thrips was documented on 40,700 acres of Berkshire and western Franklin, Hampshire, and Hampden Counties in Massachusetts. Damage in Vermont was down from 1998, but heavy defoliation did occur. Refoliation was limited and browning increased over the course of the summer, in combination with anthracnose infection. 

 

Red pine scale

Matsucoccus resinosae

 

Region 9/Northeastern Area: Massachusetts

Host(s): Red pine

 

The annual aerial survey identified 150 acres of red pine plantation mortality in Hampden and Berkshire Counties in Massachusetts. The follow-up ground surveys identified the presence of the fungal pathogens Diplodia and Fusarium as well as red pine scale. The sudden death of these red pine stands is thought to have been caused by a combination of the above factors, coupled with the 1999 season drought. This is the first time that red pine scale has been documented in Massachusetts.

 

Satin moth

Leucoma salicis

 

Region 9/Northeastern Area: Maine, Vermont

Host(s): Aspen

 

Defoliation of woodland aspen by this species increased in Maine in 1999 both in area and intensity. The infested area expanded in previously infested areas in Penobscot and Piscataquis Counties from 150 acres in 1998 to 3,767 acres in 1999. Moth catches statewide, however, rose only slightly. In Vermont, defoliation occurred in scattered locations.

 

 

Smaller Japanese cedar longhorn beetle

Callidiellum rufipenne

 

Region 9/northeastern Area: Connecticut, New York

Host(s): Arborvitae, eastern red cedar

 

In the fall of 1998, this exotic beetle was found infesting arborvitae in Milford in New Haven County, Connecticut. This is only the second report of the beetle in the United States outside a port of entry. The first repot was in North Carolina in 1997. This is also the first time in this country that the insect had completed its life cycle in a live, healthy plant. The pest has now been recorded in many locations in southwestern Connecticut and a few sites in southeastern New York. This finding has posed an immediate threat to the nursery industry in Connecticut.

 

 

Diseases: Native

 

Eastern Dwarf Mistletoe

Arceuthobium pusillum

 

Region 9/Northeastern Area: Maine, Minnesota, New Hampshire, New York, Vermont, Wisconsin

Host(s): Black spruce, red spruce, white spruce

 

Endemic levels of infection persisted in all these northern states.

 

Oak wilt

Ceratocystis fagacearum

 

Region 9/Northeastern Area: Iowa, West Virginia, Wisconsin

Host(s): Black oak, bur oak, red oak, scarlet oak

 

Tree mortality caused by oak wilt continued to occur across Iowa, affecting an area of 1,719 acres. In West Virginia, aerial oak wilt surveys were conducted in 14 counties. Oak wilt diseased trees were only found in Grant County, which is historically known to have active oak wilt centers. Drought during the summer may have contributed to tree decline and the number of oak wilt centers detected. In Wisconsin, three separate infection centers were found in Florence County in 1999.

 

 

 

 

Rhabdocline needlecast

Rhabdocline pseudotsugae

 

Region 9/Northeastern Area: West Virginia

Host(s): Douglas-fir

 

This was the first report of this disease in West Virginia. Approximately 50 acres were infested in Hardy, Berkeley, and Mineral Counties in Christmas tree plantations.

 

 

Diseases: Non-native

 

Beech bark disease

Cryptococcus fagisuga and Nectria coccinea var. faginata

 

Region 9/Northeastern Area: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Pennsylvania, Vermont, West Virginia

Host(s): American beech

 

This disease, which was introduced to Maine in the early 1930’s, continued to kill or reduce the quality of beech stems Statewide. But beech bark disease does not threaten to eliminate beech from the Maine forest because some trees are resistant, and even susceptible trees sprout profusely from roots when trees are damaged, killed, or harvested. Decline of American beech caused by beech bark disease was documented on 850 acres in Berkshire County in Massachusetts. Beech bark disease continued to be prevalent in New York, with over 90 percent of the trees surveyed having evidence of the disease. In Vermont dry conditions led to an increase in chlorosis, dieback, and mortality on infected trees.

 

Dutch elm disease

Ophiostoma (=Ceratocystis) ulmi

 

Region 9/Northeastern Area: Areawide

Hosts(s): American elm

 

Symptoms of Dutch elm disease were conspicuous throughout Maine during 1999. Many old elms, which escaped the initial wave of infection, now succumb each year, at least partially the result of the development of more aggressive strains of the disease organism. Mortality of younger elm trees (4-8" dbh and 20-30 feet tall) is also occurring. Numerous diseased elms were reported in Wilmington, Delaware in 1999. In the District of Columbia, infected American elms were either removed or pruned in order to help minimize the spread of the disease. Dutch elm disease surveys were initiated for the first time in Mount Ranier, Maryland. The survey found trees infected with Dutch elm disease. While conducting elm yellow surveys across Ohio, 50 counties were found infected with Dutch elm disease. In Vermont, the disease remained common.

 

European larch canker

Lachnellula willkommii

 

Region 9/Northeastern Area: Maine

Host(s): Larch

 

European larch canker is a fungal disease which originated in Europe and was first found on native larch (tamarack) in southeastern Maine in 1981. The disease is under state and federal quarantine. Surveys in 1999 of previously uninfested areas proved negative. Commercial larch seed orchards in the towns of Unity and Howland were also checked for evidence of larch canker; no disease was found. The trend for this disease is static.

 

White pine blister rust

Cronartium ribicola

 

Region 9/Northeastern Area: Areawide

Host(s): White pine

 

In Maine limited control efforts continued to manage this disease in certain high value pine stands each year. In 1999, a total of 4,319 acres of high quality pine timber was scouted for Ribes spp. plants in the Androscoggin County town of Auburn. A total of 2,782 Ribes spp. were destroyed. In Vermont, topkill and mortality were more common due to dry conditions. Wet weather the previous spring may have led to higher infection levels. Infection levels in affected areas averaged 20 percent in Christmas tree plantations and 32 percent in pole-size

stands.

 

 

Diseases: Origin Unknown

 

Butternut Canker

Sirococcus clavigignenti-juglandacearum

 

Region 9/Northeastern Area: Areawide

Host(s): Butternut

 

In Connecticut, of 704 tagged butternut trees surveyed yearly for Sirococcus cankers, only 141 remain canker free and 22 have died. In Maine, butternut canker was first found in 1993 when the disease was located in Kennebec County. Surveys for this disease in succeeding years indicate that the canker is now located in all Maine counties except Washington County.

 

 

 

 

Dogwood anthracnose

Discula sp.

 

Region 9/Northeastern Area: Connecticut, Delaware, Indiana, Maine, Maryland, Massachusetts, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia

Host(s): Flowering dogwood, dogwood

 

The incidence of dogwood anthracnose continued to be prevalent in all three Delaware counties. Dead and dying dogwood trees were quite noticeable in many areas of the State. Dogwood anthracnose is now found in all counties in Maryland. Visual symptoms of this disease were reported in Franklin, Essex, and Bristol Counties in Massachusetts, however, no samples were collected for positive diagnoses in the laboratory. In New York, a survey for dogwood anthracnose was performed to determine if the disease has spread to areas in which it was not previously recorded. As a result of this survey, new records of the disease were found in 18 counties. In West Virginia, diseased and dying trees were found in every county. Over the ten-year period in which this survey has been conducted, mortality increased from 8.8 percent in the first survey to 44.1 percent in the 1999 survey. During the same time period, there was a dramatic change in the number of healthy dogwoods from 49 percent healthy dogwoods in the first survey to 0.4 percent in the 1999 survey. This shows a general trend where the native dogwood population is moving from a healthy state to one of decline and mortality.

 

 

Declines/Complexes

 

Elm yellows

 

Region 9/Northeastern Area: Maryland, Ohio, Pennsylvania, West Virginia

Host(s): American elm, slippery elm

 

A multi-State survey detected disease symptoms and mortality due to elm yellows. Areas affected are presently contained within a large area extending north into Pennsylvania, south past Winchester, Virginia, and east and west bounded approximately by Martinsburg, West Virginia, and Frederick, Maryland. In Pennsylvania alone, 3,180 acres, in 45 counties, are infested with elm yellows, but a few counties appear to have a limited distribution of the disease. Based on ground surveys, elm yellows occurs scattered in 31 counties across the State in Ohio. In West Virginia, elm yellows surveys were conducted in the Eastern Panhandle as well as Brooke and Hancock Counties. Diseased and dying trees were detected in Brooke, Jefferson, Berkeley, and Morgan Counties. A major outbreak of elm yellows disease is still occurring in Jefferson, Berkeley, and Morgan Counties.

 

Larch Stressors - Eastern larch beetle (Dendroctonus simplex),  Larch casebearer (Coleophora laricella), Larch sawfly (Pristiphora erichsonii), and variable water levels

 

Region 9/Northeastern Area: Maine

Host(s): Larch

 

Native eastern larch and some larch hybrids have been under serious stress from several pests and significantly fluctuating water levels in the recent past and especially during 1999. During 1999 combinations of these agents resulted in significant larch mortality in pockets and to individual trees throughout eastern Maine. Approximately 10,800 acres of seriously defoliated, discolored, and dead larch were mapped. In addition to this mapped acreage, scattered individual larch and small clusters of stressed or dead trees were seen throughout eastern and northeastern Maine (over 1.2 million acres). Larch sawfly has caused near complete defoliation on scattered larch stands since 1997. Defoliated regions have varied from year to year but the hardest hit areas include central Penobscot, eastern Piscatiquis, southeastern Aroostook, and southern Washington

Counties. Near complete defoliation of larch for two successive seasons have caused branch, top, and whole tree mortality in several areas.

 

 

Abiotic

 

Drought

 

Region 9/Northeastern Area: Delaware, Massachusetts, Missouri, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia

Host(s): Red oak, hardwoods, conifers

 

In Delaware, a severe drought was experienced and has the potential to cause significant forest health problems in 2000. Decline attributed to drought was recorded on 4,885 acres in Massachusetts, with most of the symptoms recorded on south and southwest slopes and those areas with shallow soils and ledge outcrops. Foliage discoloration of hardwoods by August and browning of needles on white pine, was reported statewide in Missouri. New Jersey also experienced a severe drought with deciduous trees on ridge tops in the northern part of the State experiencing drought symptoms. Drought surveys focused on southeastern New York including New York City and Long Island. The lower Hudson Valley was most affected by the drought, with over 70 percent of the trees surveyed showing some affects. The most prevalent type of damage was discoloration of the foliage with few trees showing defoliation or general decline due to the drought. One beneficial effect of the drought on the forest trees was the decreased incidence of tar spot on maples. Conditions in Ohio were hotter and drier than average. As of September, Ohio precipitation levels were 5 to 6 inches below normal. The drought of 1999 was one of the most severe droughts on record throughout most of Pennsylvania. Drought stress appeared most severe along ridge tops. The symptoms of drought stress have been observed on many forest tree species including hemlock, sugar and red maple, red oak, birch, black cherry, white pine, and chestnut oak. Symptoms of drought injury included leaf scorch, premature leaf drop, twig and branch dieback, foliage wilt, and abnormal foliage coloration. Some tree mortality has been observed throughout the drought affected region, but mortality is not widespread at this time. Drought caused major stress to the forests of Rhode Island. In Vermont, the drought led to widepspread browning and yellowing on hardwoods by late summer, especially on roadside trees and ledgy sites. In West Virginia, the summer of 1999 was a record drought season and the state was declared a drought disaster by USDA. Drought impact was most noticeable on ridge tops and south facing slopes. Large numbers of trees showed signs of dieback and mortality.

 

 

 

 

 

Fire

 

Region 9/Northeastern Area: West Virginia

Host(s): Various hardwoods and conifers

 

In 1999 in West Virginia, 1,875 fires burned over 84,000 acres in the State, causing an estimated $25 million in damage.

 

Ice

 

Region 9/Northeastern Area: Maine, New Hampshire, New York, Pennsylvania, Vermont

Host(s): Various hardwoods and conifers

 

Four acres of red pine at Fort Necessity, Pennsylvania, were damaged due to an ice storm. In Vermont, a snowstorm in late September caused crown breakage in several sugarbushes in Franklin County. Recovery continued from the extensive 1998 ice storm in Maine, New Hampshire, New York, and Vermont, with smaller than normal leaves and epicormic branching occurring on many of the affected trees. Severe branch and stem breakage is still evident within impacted areas.

 

Salt damage

 

Region 9/Northeastern Area: Maryland

Host(s): Pines

 

Following hurricane Dennis in September, salt spray affected trees near the towns of Ocean City and Berlin, Maryland.

 

 

 

 

Wind/tornado

 

Region 9/Northeastern Area: Minnesota, New Hampshire, Vermont, Wisconsin

Host(s): Various hardwoods and conifers

 

This is the second consecutive year of severe wind damage to forests in Minnesota and Wisconsin. On July 4th, in Minnesota, straight-line winds blew down and damaged trees on 465,000 acres, 380,000 of which were in the Boundary Waters Canoe Area. That same storm, and another one a couple of weeks later, resulted in blow down and damaged trees in northern Wisconsin over a widespread area encompassing 50,000 acres. Also on July 4, storms blew down trees in Orleans and Essex Counties in Vermont. In southern Vermont, severe damage was caused by a storm on July 6 and winds associated with Hurricane Floyd in mid-September blew down trees in scattered locations. In New Hampshire, on August 13, 1999 a tornado caused an eight-mile swath of damage, affecting 200 acres in Sullivan and Grafton Counties.