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FS Shield
2003
Forest Insect and Disease
Conditions for the Southern Region


Note: bold hypertext links within the narratives (e.g., Dogwood Anthracnose) will take visitors to the on-line publication, The Health of Southern Forests that displays additional graphics and discusses the biology and southern history of the causal agent in more detail. Not all causal agents are linked. Non-bolded links provide for within-document navigation.

Most Significant Conditions in Brief

The impact of serious pests and other stressors was moderate in southern forests in 2003. The five-year drought that ended in 2002 continued to abate, with normal to wet conditions recorded throughout the region.

Southern pine beetle populations declined dramatically from those of 2003 throughout the South. Only South Carolina, Tennessee, and Mississippi reported significant activity, and most of that dropped sharply as late summer approached.  Elsewhere, southern pine beetle populations were low to immeasurable. 

The red oak borer outbreak associated with severe oak decline in north central Arkansas and northeastern Oklahoma continued. Mortality of red oaks has been high since 1999, but did diminish somewhat in 2002 and 2003. Nevertheless, despite the return of more normal rainfall patterns, heavy losses continue in the Arkansas Ozarks.

Infestations of the hemlock woolly adelgid in the Southern Appalachians intensified and spread in 2003. The adelgid is now present in northern Georgia, upstate South Carolina, nearly all of western North Carolina, east Tennessee, and most of the western half of Virginia. Entomologists continue to identify, rear, and release predators from the adelgid’s native East Asian range, but progress has not kept pace with the growing spread. Forest ecologists and entomologists note that the insect endangers the very survival of both eastern and Carolina hemlocks throughout the range of these species. Because of its important role in riparian ecology, the loss of hemlock could have a devastating impact on aquatic ecosystems.

Gypsy moth defoliation, while heavier than in 2002, was nonetheless moderate compared to years past. Cool, wet weather in the late spring hindered larval development. Moreover, the Entomophaga fungus killed many larvae before they were fully grown. Poor survival in 2003 portends well for the 2004 defoliation season.

In Southern Appalachians, the beech bark disease complex worsened in 2003. Infections were confirmed in seven new counties in Virginia, Tennessee, and North Carolina. Beech is an important species for wildlife, providing both mast and den habitat for species like black bear.

Turning to abiotic conditions, with the exception of unusually heavy tornado activity in Tennessee and Virginia, there were few weather extremes in 2003. Only one hurricane made landfall in Virginia and Eastern North Carolina, and its impact on forests and forestry was minor compared to the storms of recent years.

Status of Forest Insects

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Insects:   Native

Baldcypress leafroller,
Archips goyerana

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Region 8:   Louisiana

Host(s):   Baldcypress

In 2003, 138,500 acres of mixed baldcypress stands in southern and southeastern Louisiana were defoliated by the baldcypress leafroller. (Ascension, Assumption, Iberia, Iberville, LaFourche, St. Charles, St. James, St. John the Baptist, St. Martin, and Terrebonne Parishes.) Approximately 57,400 acres were severely defoliated (>50%). The primary impact of this defoliation is loss of radial growth, producing an estimated growth loss of 0.1 MBF/acre. Dieback and scattered mortality occurred in some areas. Permanently flooded areas were most severely impacted.

Black turpentine beetle,
Dendroctonus terebrans

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Region 8:   Regionwide

Hosts:   Loblolly pine, longleaf pine, slash pine, shortleaf pine

Much like pine engraver beetles, the black turpentine beetle (BTB) prefers to attack stressed, weakened trees. Stands stressed by multiple factors such as drought and logging injury, compacted soil, or wildfires are especially vulnerable. BTBs are active in the lower six to eight feet of the tree’s bole. Although generally present at low population levels, when BTB numbers increase significantly, they are capable of attaining primary pest status, attacking trees with no overt damage or other evidence of susceptibility. Levels of activity were mostly declining or low in 2003, with observed attacks generally involving individual stressed or damaged trees, or those that were also being attacked by Ips beetles or SPB. Florida reported BTB infestations at levels of 10-25% in five slash pine plantations three to twelve months after these stands had been properly thinned. BTB was also reported sporadically throughout northern parts of the state in association with stressed or injured pines. Georgia reported some increases in BTB activity, associated both with commercial thinnings and with annosum root disease. The Georgia Forestry Commission also reported that the type of equipment used in mechanical thinnings appeared to influence susceptibility of the residual stand to BTB, probably because shears tend to pinch off resin flow, while saw-type cutting heads produce free-flowing resin that attracts the beetles. In South Carolina, BTB activity increased in areas where pine roots suffered from oxygen depletion following excess spring rain. Sites most affected were on loamy soils with subsoil hardpans (old agricultural sites). Losses in some stands exceeded 25%. Virginia reported continuing high incidence of BTB activity, especially in the southeastern mountains, apparently due to residual tree stress from the recent protracted drought and a high carry-over population of BTB.

Buck moth,
Hemileuca maia

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Region 8:  Louisiana

Hosts:  Live oak and other hardwoods

Buck moth defoliation of live oak has been a problem in New Orleans for many years.  The moth continues to be locally abundant in the city and of particular concern in the Federal Historic Districts.  The insect population in Louisiana was found to be decreasing in 2002, and this trend continued in 2003. On the Cumberland Plateau and central sections of Tennessee, however, reports of buck moth defoliation increased. Virginia reported scattered light-to-moderate buck moth defoliation in 2003.

Cypress weevil,
Eudociminus mannerheimii

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Region 8:  Florida

Host:  Baldcypress

About 30 potted baldcypress, approximately one inch in diameter, were infested by larvae of the cypress weevil in a commercial ornamental nursery, with damage initially detected in September and October. This small, isolated infestation is notable due to the lack of published information regarding this insect and its apparent rarity as a commercial nursery or forest pest. Larvae tunneled in both phloem and xylem tissues before boring through the center or the sapling main stems.

Fall cankerworm,
Alsophila pometeria

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Region 8:  Kentucky, Tennessee, Virginia

Hosts:  Various oak species

Eastern, southeastern and central Kentucky experienced an explosion in cankerworm populations, resulting in significant oak defoliation. It is unclear whether this defoliation is a significant contributor to the increased incidence of oak decline and mortality observed in these areas. High cankerworm populations are expected to persist in 2004.

There was an increase in scattered defoliation by fall cankerworms in several counties in northeastern Tennessee, usually found in combination with other inchworm and cutworm defoliators. In Virginia, cankerworm populations were moderate statewide, with several areas of heavy defoliation. Heavily defoliated areas were estimated to total 8,397 acres.

Forest tent caterpillar,
Malacosoma disstria

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Region 8:  Louisiana, South Carolina, Texas

Hosts:  Tupelo gum, upland hardwoods

Defoliation of tupelo gum occurred on 96,300 acres of forested wetlands (baldcypress/water tupelo forest type) in Ascension, Livingston, St. James, and St. John Parishes in southeasern Louisiana in 2003. This defoliation was severe (>50%) on 57,900 acres, a decline from the previous year. South Carolina reported 589,120 acres of defoliation in 11 counties in 2003, a major increase over 2002. The primary river basins affected were the Congaree, Great Pee Dee, Little Pee Dee, Santee, and Wateree, although many swamps outside of the major river bottoms also experienced defoliation. Pure stands of gum were the most seriously damaged, with 100% defoliation in many areas; oaks and other hardwoods on the affected acreage suffered more than 50% defoliation. In Texas, an unusual outbreak in the lower Trinity, Neches, and Sabine River bottoms that was reported in 2002 abated in 2003. Hosts were primarily sweetgum and oaks.

Giant bark aphids,
Longistigma caryae

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Region 8:  Texas

Hosts:  Oaks

The 2002 outbreak of giant bark aphids across most of eastern Texas abated in 2003. No other outbreaks were reported.

Gouty oak gall,
Plagiotrochus punctatus

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Region 8:  Arkansas

Host(s):  Willow oak

An unusually severe outbreak of gouty oak gall has been occurring for several years in the bottomland forest on the Lower Ouachita Wildlife Management Area in UnionCounty in extreme southern Arkansas, affecting about 500 acres. The area is often flooded, putting the trees under stress. These and other factors may be involved in causing mortality.

Grasshoppers,
Various spp.

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Region 8:  Oklahoma, Tennessee

Hosts:  Oaks, other hardwoods

Damage by grasshoppers in post and blackjack oak stands in central Oklahoma continued in 2003, although the damage was much less severe. Light grasshopper defoliation was also reported in the northern highland rim, Cumberland Plateau, and southeastern sections of Tennessee.

Juniper budworm,
Cudonigera houstonana

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Region 8:  Texas

Hosts:  Ashe juniper

The unusual outbreak of juniper budworm that defoliated trees in central Texas in 2002 abated in 2003. No other outbreaks were reported.

Locust leafminer,
Odontata dorsalis

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Region 8:  Georgia, Kentucky, North Carolina, South Carolina, Tennessee, and Virginia

Host:  Black locust

While locust leafminer activity was observed across the entire range of the species, the level of damage declined significantly from 2002. The most severe damage reported was on upper slopes in middle and eastern Tennessee and western North Carolina. In Virginia, leafminer damage appeared later than usual in 2003.

Nantucket pine tip moth,
Rhyacionia frustrana

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Region 8:  Regionwide

Hosts:  Loblolly pine, shortleaf pine

Activity was low or declining throughout most of the region in 2003. Tennessee reported only three generations of tip moths, producing light to moderate defoliation. Some old-field sites in South Carolina suffered 25-50% attacks on lateral and terminal branches, although damage was generally lower than in 2002 statewide. Virginia reported chronic heavy infestations.

Oak leaf tier,
Croesia semipurpurana

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Region 8:  Tennessee

Hosts:  various oak species

Increased levels of oak leaf tier damage were reported in central and western Tennessee, generally in combination with inchworms. No other significant occurrences were reported.

Orangestriped oakworm,
Anisota senatoria

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Region 8:  Texas

Host(s):  Various oak species

A small outbreak of orangestriped oakworm was reported in Angelina, Nacogdoches, Panola, and ShelbyCounties. Such outbreaks occur periodically, but generally produce little damage.

Pine colaspis beetle,
Colaspis pini

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Region 8:  Louisiana, Virginia

Hosts:  Southern pines, ornamental cypress

As in previous years, this beetle caused localized defoliation of pine plantations in eastern and central Louisiana, particularly in eastern Rapides Parish and the southeastern-most parishes. No significant damage occurred, but the defoliation is unsightly and causes landowner concerns. Some mortality of ornamental cypress was noted during droughty periods. Virginia reported light and scattered damage.

Pine engraver beetle,
Ips calligraphus, I. grandicollis, I. avulses

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Region 8:  Regionwide

Hosts:  Loblolly pine, shortleaf pine, slash pine

Reduced levels of pine engraver beetle activity were reported across most of the region. Small spots averaging seven trees each were reported from Tennessee, often in concert with SPB and BTB. Arkansas and Louisiana reported 16 and 50 spots, respectively. Scattered damage continued in southeastern Oklahoma, generally in only one- or two-tree spots. Little activity was detected in Texas. Virginia reported a decline in Ips activity in comparison to the previous two years. South Carolina reported increased activity on rain-saturated sites, much like that reported for BTB.

Pine sawflies,
Neodiprion sp., Diprion sp.

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Region 8:  Florida, Louisiana, North Carolina, Tennessee, Texas, Virginia

Hosts:  Southern pines

Florida experienced approximately 1400 acres of defoliation by the blackheaded pine sawfly in DixieCounty. The heaviest damage occurred in July. Reduced defoliation by the loblolly pine sawfly was reported in middle Tennessee, with only six counties affected; defoliation was less than 50% except in scattered areas. Redheaded pine sawfly activity was also reduced in Tennessee, especially in the southeastern portion of the state. South Carolina reported several redheaded pine sawfly infestations in young longleaf plantations. The largest covered 25 acres and required insecticide treatment. Virginia reported only a few defoliating sawfly populations in 2003. Mississippi reported 2 small infestations in MarshallCounty.

Red oak borer,
Enaphalodes rufulus

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Region 8:  Arkansas, Oklahoma, Virginia

Hosts:  Northern red oak, black oak

The red oak borer epidemic persisted in 2003 in north central Arkansas and northeastern Oklahoma in association with oak decline exacerbated by the recent years of drought. The cumulative effects of drought, insects, pathogens, and advanced age in these forests has produced levels of decline from which most trees will not be able to recover. The return of normal precipitation is expected to put downward pressure on the red oak borer population, but mortality and degrade of lumber quality among oaks is already severe. Adult borers emerged in 2003, and with their two-year life cycle, another emergence will not occur until 2005. Virginia reported chronic low to moderate populations of borers in 2003. (See also Oak decline, abiotic and biotic influences under Declines/Complexes).

Reproduction weevils,
Hylobius pales, Pachylobius picivorous

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Region 8:  Regionwide

Hosts:  Southern pines

Reduced levels of attack (1-20% seedling mortality) were reported in southeastern Tennessee, the Cumberland Plateau, and in the eastern part of the state south of Knoxville. Severe impacts were noted on a 200-acre tract in Harrison County, Texas, where scattered damage is reported in most years. In South Carolina, weevil damage increased from 202 levels. Fifteen separate plantations containing approximately 800 acres of loblolly pine seedlings suffered 50-75% mortality. Weevil damage was generally low in Virginia, owing to chemical treatment of planted seedlings in high-hazard areas.

Southern pine beetle,
Dendroctonus frontalis

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Region 8:  Regionwide

Hosts:  Loblolly pine, shortleaf pine, slash pine, longleaf pine, Virginia pine, eastern white pine

Southern pine beetle (SPB) activity declined dramatically across the region (map showing southern pine beetle outbreak counties).  In 2003 there were 7,644 SPB infestations versus 61,089 in 2002 (Table 1). 

Table 1. Southern Pine Beetle Infestations by State --  2002 versus 2003

State

2002

2003

Percent
Difference

Alabama

5,053

204

-95.96

Arkansas

0

0

0

Florida

650

2

-99.69

Georgia

9,708

283

-97.08

Kentucky

18

0

-100

Louisiana

0

0

0

Mississippi

701

75

-89.30

N. Carolina

4,533

161

-96.45

Oklahoma

0

0

0

S. Carolina

33,555

5,625

-83.24

Tennessee

6,639

1,294

-80.51

Texas

0

0

0

Virginia

232

0

-100

Totals

61,089

7,644

-87.49

 

Residual beetle activity lingered in western South Carolina and eastern Tennessee.  There was also an increase on National Forest land in Mississippi.   Otherwise most states had no to very low levels of SPB activity.

Tennessee reported 12 counties still in outbreak status with a total of 1,294 spots, but reduced activity was noted, with no spots over 50 trees. South Carolina reported 18 counties still in outbreak status, but only in the single mountain county was the continuing damage considered significant. The majority of activity was early in the year, carrying over from the record setting outbreak of 2002. Alabama reported only 197 spots, Mississippi only 75, while no spots were detected in Arkansas, Louisiana, Oklahoma, or Texas. The SPB outbreak in North Carolina began to collapse in late 2002 with the return of normal precipitation. Only 120 spots were reported statewide in 2003, with most of these concentrated in Cherokee County, in the southwestern tip of the state. The outbreak in Virginia’s southwestern mountains and isolated areas of the central Piedmont also collapsed in 2003. Florida detected only two SPB spots in 2003, representing the lowest level of activity since 1992. Decline of SPB activity corresponded closely with the end of the recent drought.

Texas leaf-cutting ant,
Atta texana

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Region 8:  Louisiana, Texas

Hosts:  Southern pines and hardwoods

Localized defoliation of pine plantations occurs annually in east Texas and west central Louisiana on sites with deep, sandy soil. Populations of these ants remain relatively stable from year to year.

Yellow poplar weevil,
Odontopus calceatus

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Region 8:  Tennessee

Host:  Yellow poplar

Reduced populations were reported in 2003; leaf damage remained below 10%. Virginia reported light populations throughout the southwestern mountains.

Insects:  Nonnative

Ambrosia beetles,
Xyleborus similis, Xylosandrus mutilatus

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Region 8:  Tennessee

Hosts:  Pines or hardwoods

A South-wide trapping effort to detect the recently discovered Xylosandrus mutilatus was implemented in 2003. An infestation in one black walnut plantation in western Tennessee was reported in which these beetles, in conjunction with a canker fungus, rapidly killed 5% of the trees.

Asian longhorned beetle,
Anoplophora glabripennis

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Region 8:  Regionwide

Hosts:  Hardwoods

No occurrences of this pest were reported in the region in 2003.

Balsam woolly adelgid,
Adelges picea

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Region 8:  North Carolina, Tennessee, Virginia

Host:  Fraser fir

Fraser fir has a very limited range in the southern Appalachian Mountains and appears almost exclusively in pure stands on the highest mountain peaks or in combination with red spruce at somewhat lower elevations (map showing spruce/fir distribution). Since the introduction of the balsam woolly adelgid, approximately 64,700 acres of Fraser fir have been affected.  The insect attacks all age classes, but prefers older trees. The summer of 2003 witnessed high populations in all infested areas.  However, there is an abundance of uninfested or lightly infested regeneration in most areas. Many casual observers believe this portends well for the future, but in fact, these trees will almost certainly become heavily infested as they mature.

Black twig borer,
Xylosandrus compactus

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Region 8:  Florida

Hosts:  Red bay, dogwood, eastern redcedar, others

Black twig borers were notably active in northern Florida in the spring of 2003, with damage reported in six counties. The primary impact was to the aesthetic quality of infested trees.

Gypsy moth (European),
Lymantria dispar

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Region 8:  Arkansas, Georgia, North Carolina, Tennessee, Virginia

Hosts:  Hardwoods, especially oak species

Virginia reported 79,927 acres of gypsy moth defoliation, a modest increase over 2002 levels (map showing 2003 gypsy moth defoliation area). In 2003, the egg hatch was poor in some areas, and cool, wet weather combined with a late spring freeze hindered larval development. Entomophaga fungus activity killed many larvae before they were fully grown. Because of this, the potential for defoliation in 2004 appears low.

In 2003, Tennessee trapped a total of 208 moths in 18 counties, reflecting a decrease from the 1,630 moths captured in 2002. Three areas in the state are currently infested; eradication activities were conducted on 16,419 acres in Campbell County. No moths were captured in Monroe and Wilson Counties, although mass trapping is planned.  The moth was eradicated from sites in Scott and Sevier Counties in 2003.

The Gypsy Moth Slow the Spread Project (STS) conducted aerial treatments in seven states.  In the southern region, STS treatments took place in Virginia and North Carolina (Table 2).

Table 2.  Acres treated in the Southern Region as part of the STS project during 2003

Ownership

State

Acres of Treatment in 2003

 

Gypchek

Btk

Dimilin

Mating Disruption

Total acres treatment

Private

NC

 

15,557

0

0

15,557

Private

VA

206

2,789

0

82,240

85,235

Jeff NF

VA

 

0

0

24,715

24,715

             

Total acres

   

18,346

   0

106,955

125,507

More than 90% of the treatment acreage is accomplished using mating disruption, a tactic that is specific to the gypsy moth. A significant increase in male moth captures was noted in North Carolina during 2003. This is believed to have been the result of a “blow-in” of moths from infested areas to the north due to unusual weather conditions, but this can only be determined by conducting egg-mass surveys, an activity planned for the 2003-04 winter. 

Hemlock woolly adelgid,
Adelges tsugae

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Region 8:  Georgia, North Carolina, South Carolina, Tennessee, Virginia

Hosts:  Carolina hemlock, Eastern hemlock

Infestations of the hemlock woolly adelgid spread and intensified in the Carolinas and northern Georgia in 2003, and its first observed occurrence in eastern Tennessee was reported (map showing hemlock woolly adelgid occurrence by county). Two new counties in South Carolina were reported to be infested. Efforts at chemical control were undertaken in the Great Smoky Mountains National Park, and the rearing and release of adelgid predators was expanded. However, the expanding infestation continues to outpace control efforts and the prognosis for survival of both of the eastern hemlock species in the wild is grim.

Lobate lac scale,
Paratachardina lobata lobata

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Region 8:  Florida

Hosts:  Melaleuca; over 100 other woody species

Numerous complaints were received by foresters and extension specialists in southern Florida from residents concerned about decline and mortality of  Melaleuca (Melaleuca quiquenervia) urban shade trees. The decline appeared to be largely due to infestation by the lobate lac scale, an insect native to India and Sri Lanka that has become established along much of the southeast coast of Florida since its initial detection in 1999. Ironically, Melaleuca is an aggressive exotic wetland pest plant against which federal and state agencies have released other insect biological control agents. These biological control agents sometimes occur together with lobate lac scale on urban Melaleuca trees, but the urban decline seems to be driven primarily by the scale. It is not yet known whether the scale will also attack native woody plant species.

Pine cone beetle,
Chlorophorus strobilicola

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Region 8:  Florida

Hosts:  Pine spp.

In December 2003, live adults and larvae were found in scented pine cones contained in scented potpourri sold in Target and Wal-Mart stores in several locations in Florida, including Lake Mary, Largo, Tampa, Jacksonville, Coral Springs, and Murdock. The scented cones were imported from India and the USDA has instituted a national recall on the product, with the cooperation of the Florida Commissioner of Agriculture. It is uncertain whether or not this beetle could successfully infest cones of native southern pines.

Pink hibiscus mealybug,
Maconellicoccus hirsutus

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Region 8:  Florida, Puerto Rico, Virgin Islands

Hosts:  Hibiscus, many other species

The pink hibiscus mealybug (PHM) is a serious pest of over 200 plant species, and is known to occur on more than 20 CaribbeanIslands. It was detected in Puerto Rico in 1997, but to date no infestations have been identified on the CaribbeanNational Forest.  Frequent monitoring surveys are conducted, assisted by the USDA Forest Service. It appears that parasitoids were introduced simultaneously with the mealybug, reducing the impacts in Puerto Rico. With support from the USDA Forest Service and Animal and Plant Health Inspection Service, the Puerto Rico Department of Agriculture continues to rear and release two species of parasitic wasps to combat the PHM. Surveys indicate population reductions of 85-90 percent have been achieved at the parasitoid release sites.

An infestation was detected in Miramar County, Florida in June 2002.  By mid-July, it had spread to Broward and Miami-Dade counties and encompassed 22 square miles.  The USDA and the Florida Division of Plant Industry initiated weekly releases of parasitoids in the infested areas, utilizing parasitoids reared in Puerto Rico.  At the time the two parasitoids were released, the coccinellid Cryptolaemus montrouzieri, a predator, was commonly found in PHM infested areas.  A total of 254,000 A. kamali and 295,000 G. indica were released in 604 sites from July 8, 2002 to August 7, 2003.  As of August 7, 2003, releases have covered approximately 121 square miles.  Population reductions of the PHM range from 92-97%, and hibiscus not killed by initial infestations are recovering.  Parasitism rates near release sites have been variable, and in many cases the predators appear to be the main source of mealybug population reduction.  Hyperparasites also have been discovered.  The range of the PHM is expanding slowly, and the natural enemies appear to be spreading along with their hosts.  Continued parasitoid releases are planned for 2004.

Status of Forest Diseases

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Diseases:  Native

Annosum root disease,
Heterobasidion annosum

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Region 8:  Regionwide (map showing annosus hazard rating)

Hosts:  Southern pines

South Carolina reported slight declines in annosum root disease losses, apparently as a result of the relief from recent drought stress. Surveys indicated 50,040 acres of pine stands affected by the disease in sandy sites across the state, representing a timber value loss of $1,351,080. In Florida, this disease is an ongoing problem. Not only are serious losses suffered in scattered plantations, annosum root disease is also associated with SPB and other bark beetles and is often a precursor to their infestations. It occurs in both thinned and unthinned pine stands. In 2003 annosum losses were reported in Barbour, Macon, and Russell Counties in Alabama; Marion and Stewart Counties in Georgia; Aiken and Bardwell Counties in South Carolina. Annosum was also reported affecting white and red pine stands on the Dry River Ranger District of the George Washington-Jefferson National Forest in Virginia.

Cercospora needle blight,
Cercospora sp.

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Region 8:  South Carolina

Host(s):  Leyland cypress

Cercospora needle blight was found in four Leyland cypress Christmas tree plantations in South Carolina. Fungicide control has been suggested for growers experiencing problems with this disease. The lack of genetic variation in this species due to asexual propagation is believed to contribute to newly discovered disease problems.

Fusiform rust,
Cronartium quercuum f. sp. Fusiforme

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Region 8:  Regionwide

Hosts:  Southern pines, especially loblolly and slash pines

Fusiform rust continues to be the most significant disease of loblolly and slash pine in the South. In Florida, a survey of 280 plantations was completed in 2003. Comparisons of fusiform rust levels in longleaf pine and both “improved” and “rust-resistant” slash pine sold by the Florida Division of Forestry were drawn, showing that infection levels were significantly lower in “rust-resistant” than in “improved” slash pine, while longleaf pine produced the lowest overall levels of infection. Other anecdotal reports suggest that the incidence of main stem infection is decreasing, and that the disease is becoming more confined to branches where the impact is minimized.  The Resistance Screening Center in Asheville continues to screen seed lots for fusiform rust resistance. Texas reported moderate levels of fusiform rust on scattered tracts across eastern portions of the state. Over the past few years, rust infection levels have been declining for several years, in part because of reduced planting of slash pine.

Littleleaf disease,
Phytophthora cinnamomi

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Region 8:  Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee, Virginia

Hosts:  Loblolly pine, shortleaf pine

Littleleaf disease continues to cause growth loss and mortality across the Piedmont areas of the affected states. Shortleaf pine is highly susceptible while loblolly pine is affected, but at a later age. Many of the stands that were converted from shortleaf to loblolly to reduce the impact of this disease are now reaching the age of susceptibility. Bark beetles often attack these stands once they have been weakened by the root infection. Some moderation of littleleaf symptoms over time has been reported. It is believed that root penetration of soil hardpans and gradual increases in soil porosity due to increasing biological activity on severely eroded sites will gradually reduce the impact of this disease over a period of a century or more.

Hypoxylon canker,
Hypoxylon spp.

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Hosts:  Oaks

Red oaks in northeastern Tennessee have shown increasing levels of hypoxylon infection in response to the recent drought. White oaks have also been reported to display increasing rates of hypoxylon infection in the northern Cumberland Plateau. This disease continues to be a significant component in the general epidemic of oak decline in Arkansas oak forests.

Oak wilt,
Ceratocystis fagacearum

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Region 8:  North Carolina, Tennessee, Texas, Virginia

Hosts:  Live oak, red oaks

Oak wilt continues to devastate more than 66 central Texas counties, mostly between Dallas and San Antonio.  Urban, suburban and rural oaks are affected.  Live oak, the premier shade tree species in the region and highly valued for beauty, shade, and wildlife benefits, was severely impacted by the disease.  Trenches dug between healthy and diseased trees sever interconnected root systems and help to halt the spread of the disease. The Texas Forest Service completed the sixteenth year of cooperative suppression of the disease.  Since this project’s inception, more than 3 million feet (568 miles) of barrier trenches have been installed on more than 2,100 oak wilt infection centers in 34 counties.  The Texas Forest Service conducted no aerial surveys for oak wilt in 2003, but control assistance was performed for at least 5,692 landowners. In Tennessee, oak wilt aerial survey flights over Lincoln, Franklin, Moore, and Marion Counties were negative in 2003, although one oak wilt center was reported in an urban setting in Sullivan County. The North Carolina Division of Forest Resources reported 25 oak wilt infection centers in the Appalachian Mountain counties of Buncombe, Haywood and Jackson in its 2003 survey.

Walnut anthracnose,
Gnomonia leptostyla

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Region 8:  Kentucky

Host:  Black walnut

Walnut anthracnose was reported in Kentucky for the first time in 2003, producing foliar damage on black walnuts in both forest and landscape settings all across the state. The appearance of this disease is thought to be related to the significant increase in rainfall during the spring and early summer. No mortality has been reported or is expected, although a continuation of foliar injury over two or three years might produce more serious impacts.

Diseases:  Non-native

Beech bark disease,
Neonectria coccinea var. faginata

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Region 8:  North Carolina, Tennessee, Virginia

Hosts:  American beech

Beech bark disease (BBD) continues to intensify and spread in eastern Tennessee, western North Carolina, and extreme West-Central Virginia, with seven new counties confirmed infected in 2003. BBD is now found in Sevier, Blount, and Cocke Counties in Tennessee; Swain, Haywood, Madison, Yancey, Mitchell, and Buncombe Counties in North Carolina; and Highland, Bath, and Rockbridge Counties in Virginia.

Tree mortality continues to intensify in and around the Great Smoky Mountains and Blue Ridge Parkway National Parks. The disease has intensified at a faster rate than predicted, and is moving down slope into the Nantahala and Pisgah National Forests. In 2003, it was confirmed that Roan Mountain State Park (Tennessee) and Mount Mitchell State Park (North Carolina) have active infestations. (Map showing beech bark disease occurrence by county)

Dutch elm disease,
Ophiostoma ulmi

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Region 8:  Regionwide

Hosts:  American elm

Localized mortality continues to occur at low severity level in urban and wild populations of elm.

Sudden oak death,
Phytophthora ramorum

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Region 8:  No yet known

Hosts:  Red and possibly some white oaks, rhododendrons, and other species

Sudden oak death (SOD) is a disease of concern that has been introduced to California, Oregon and Washington, with potential to be spread into the Southeast through importation of infected nursery stock. A pilot survey for the disease was initiated in 2003 in Georgia, North Carolina, South Carolina, Tennessee, and Virginia, sampling susceptible understory forest vegetation in areas considered to be at the highest risk for potential introduction. No SOD-positive specimens were found, but the survey will be continued and expanded in 2004.

White pine blister rust,
Cronartium ribicola

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Region 8:  North Carolina

Host:  Eastern white pine

White pine blister rust continues to be a disease of concern for North Carolina landowners.  The northwestern mountains are an area of particularly high hazard.  The disease can be especially devastating to growers of ornamentals and Christmas trees, many of whom are centered in this area.  The North Carolina Division of Forest Resources continues to review seedling applications for white pine seedlings and to screen or examine areas prior to planting.

Diseases:  Origin Unknown

Butternut canker,
Sirococcus clavigigenti-juglandacearum

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Region 8:  Regionwide

Hosts:  Butternut

This disease (map showing butternut canker occurrence by county) has been in the South for at least 40 years and is believed to have killed 3 of every 4 butternuts in North Carolina and Virginia.  The fungus kills trees of all ages.  Butternut canker is expected to spread and kill most of the resource, including regeneration.  The species will be replaced by other species on these sites (e.g., black walnut).  It is too early to predict the benefits of selection and breeding on developing resistance to the disease, but trees exhibiting resistance have been found in Arkansas, North Carolina, Tennessee, Kentucky and Virginia.

Cedar heart rot

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Region 8:  Kentucky

Host:  Eastern redcedar

A high incidence of heart rot has been detected in all age classes of eastern redcedar in central and southern Kentucky, adversely impacting lumber values for this species. KY Division of Forestry and pathologists with the University of KY are cooperating in efforts to identify the pathogen responsible for this disease.

Dogwood anthracnose,
Discula destructive

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Region 8:  Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee, Virginia

Host:  Flowering dogwood

Dogwood anthracnose continues to intensify within the generally infested area (map showing dogwood anthracnose occurrence by county). North Carolina reports continuing mortality attributable to dogwood anthracnose in mountain counties.  In 2003 there were no reports of additional counties being impacted (Table 3). One new infected county was reported in Kentucky; the number of confirmed infected counties currently stands at 253 region wide. For a list of counties see the tables that follow.

Table 3. Number of counties confirmed infected with dogwood anthracnose in the South by State, 2003

State

Counties

Alabama

8

Georgia

38

Kentucky

64

North Carolina

30

South Carolina

6

Tennessee

59

Virginia

48

Total

253

 

Pitch canker,
Fusarium circinatum

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Region 8:  Regionwide

Hosts:  Southern pines

No specific reports of pitch canker were received in 2003.

 

Declines/Complexes

Loblolly pine decline,
abiotic and biotic influences

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Region 8:   Alabama, Georgia

Host(s):   Loblolly pine

Loblolly decline is a complex of interactions of biotic and abiotic stresses. Predisposing factors include site condition and host. The decline sites are predominantly upland sites with history of previous agriculture and not well suited for long term management of loblolly pine. The inciting conditions include fine root deterioration and soil factors. Loblolly decline symptoms are similar to those of littleleaf disease of shortleaf pine; however, these upland sites are not the characteristic eroded clay soils associated with littleleaf disease. The final phase contributing to the decline includes root-feeding insects on the primary roots and the vectoring of Leptographium species. As loblolly stands decline with increased stresses and stand age, they also become more susceptible to attacks by southern pine beetle. The dominant forest type on these upland sites was longleaf pine prior to the initial harvesting in the early 1900’s and longleaf restoration is recommended for long-term management of these sites.

Oak decline,
abiotic and biotic influences

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Region 8:  Regionwide

Hosts:  Oaks, other hardwoods

The oak resource in the southern United States is significant. Approximately two-thirds of the hardwood forest is classified as upland hardwood, where a malady known as “oak decline” is prevalent.  Oak decline has been reported in the United States for over 130 years.  It is a syndrome that involves the interaction of factors such as climate, site quality, and tree age; drought and insect defoliation escalate the condition.  Pests such as armillaria root disease and the two-lined chestnut borer, which are ordinarily non-aggressive pests on vigorous trees, successfully attack trees stressed by oak decline.  Decline is characterized by a gradual but progressive dieback of the crown. Mortality typically results after several years, with mature overstory trees the most heavily affected.

In South Carolina, large acreages of hardwoods suffered late season defoliation from a combination of leaf fungi and oxygen depletion due to excess precipitation and soil saturation. Aerial surveys found this defoliation on 589,120 acres in the Coastal Plain. Mortality is occurring in some areas, and ambrosia beetles and wood borers are attacking affected trees, with additional mortality expected to continue. Similar damage was reported in coastal North Carolina, but an estimate of the acreage involved was not available. In north central Arkansas and northeastern Oklahoma, widespread oak decline mortality is still prevalent, although severe drought stress has abated in 2002 and 2003. The associated red oak borer epidemic continues (see Insects-Native, Red Oak Borer). Continuing problems with oak decline were noted in Tennessee in 2003.

Baldcypress mortality,
Meruliopsis taxicola (associated, not necessarily causal)

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Region 8:  Florida

Host:  Baldcypress

In the fall of 2002 and continuing into 2003, large numbers of baldcypress were reported to be “failing,” i.e. dying and/or falling over, in or near lake margins in Lake County, Florida. Some of the failing trees were estimated to be as old as 200 years. Field evaluations revealed that the failing trees were located almost exclusively in deep muck soils around the lake margins; trees rooted in sandy mineral soils appeared unaffected. The butts and roots of affected trees were dehydrated and decayed to near “punk” condition, and cypress knees in the affected area could be lifted from the ground with almost no effort. The southern cypress beetle (Phloeosinus taxodii) was found in association with many of the failed trees, but appeared to be of secondary importance. Examination of exposed and/or excavated cypress roots revealed sporophores of the decay fungus Meruliopsis taxicola, an organism heretofore unreported both in Florida and in association with baldcypress. It is thought that drought-related water draw-down and dehydration of the muck soils around affected lake margins created habitat and host conditions suitable for M. taxicola to cause significant decay of roots and butts of the trees.

Canker and dieback of Drake elm,
Botryosphaeria spp.

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Region 8:  Florida

Host:  Drake elm

Cultivars of Chinese elm (Ulmus parvifolia) known as “Drake elms” have been popular ornamental and landscape trees in Florida for many years. In the spring and summer of 2003, numerous reports were received of cankers and dieback affecting these trees. Field and laboratory evaluations revealed Botryosphaeria theobromae and/or other Botryosphaeria anamorphs to be consistently associated with the symptoms. A superficial bloom of Fusarium lateritium on dead bark surfaces is also associated with the symptoms. In some cases, elongated callus ridges on upper branch surfaces are suggestive of “sunburn,” a scenario previously seen on this thin-barked host. The cankers and associated dieback appear to be secondary responses to environmental stress.  

Live oak cankers,
Cryphonectria cubensis

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Region 8:  Florida

Host:  Live oak

Serious, debilitating cankers on mature live oaks were reported in a new residential subdivision in Polk County. The cankers were perennial, approximately seven years of age, with elongated annual “target-like” growth rings similar to those produced by Neonectria species on certain hardwoods. No Neonectria species were observed on or cultured from cankered tissues. Laboratory isolations did, however, yield a pycnidial fungus appearing culturally and morphologically related, if not identical, to the pycnidial (anamorph) stage of Cryphonectria cubensis, a canker fungus of Eucalyptus species occurring in southern Florida. This is the second time such a fungus has been found on live oak tissues, the other being a single isolation from the roots of a declining live oak in Dade County in 1984. The significance of these observations is unknown, but it is conceivable that stress (soil disturbance, mechanical injury, hydrological changes) associated with the development of the subdivision may have predisposed the oaks to infection.

Seed Orchard Insects and Diseases

Coneworms,
Dioryctria amatella, D. clarioralis, D. disclusa, D. merkeli

Region 8:  Regionwide

Hosts:  Southern pines

Surveys indicated an average 20-25% loss of second-year cones (2003 cone crop) in untreated trees.  Damage levels in slash pine orchards were similar to those in loblolly pine seed orchards.  This loss does not include first-year flowers and conelets and is, therefore, a low estimate of the total damage caused by coneworms.  In eastern Texas, losses in unsprayed orchards declined in 2003 to about 30% from about 34% in 2002.  Losses in treated orchards were considerably less.

Pitch canker,
Fusarium circinatum

Region 8:  Regionwide

Hosts:  Southern pines

Tennessee reported scattered infections of pitch canker on shortleaf pine in the eastern part of the state; no other seed orchard effects were noted in the region. About 15% of the pinecones harvested from state seed orchards in east Texas in 2003 were apparently damaged by pitch canker.

Seedbugs,
Leptoglossus corculus, Tetyra bipunctata

Region 8:  Regionwide

Hosts:  Southern pines

Both species of seedbug were present in pine seed orchards throughout the South.  Samples of conelet ovule damage indicated that seedbugs caused about 20% seed loss on loblolly in Louisiana. Large populations of T. bipunctata occurred in September and October in orchard trees monitored in Louisiana. These estimates probably reflect those throughout the Gulf Coast states.

Southern cone gall midge,
Cecidomyia bisitosa

Region 8:  Florida

Hosts:  slash pine

This species caused localized significant loss of slash pine conelets in Florida seed orchards in 2003. Damage by this unusual insect appears to vary by clone, some clones being highly susceptible; however, little is known of the life cycle and effective management techniques are yet to be developed.

Nursery Insects and Diseases

Cutworms,
Unidentified

Region 8:   Texas

Host(s):  Loblolly pine

An unidentified species of cutworm destroyed over a million pine seedlings in an industrial pine seedling nursery in the spring of 2003. Successful control was obtained with an insecticide application.

Damping-off,
Fusarium sp., Pythium sp., Phomopsis sp., and Phytophthora sp.

Region 8:  Regionwide

Hosts:  Pines, hardwoods

Damping off is the most common disease problem facing southern nurseries.  Loss of seedlings to damping-off varies greatly from year to year owing to the interaction of pathogenic fungi and environmental conditions.  Seedling losses can be severe when germination is slow due to cold, wet weather.  Damping-off continued to be one of the most significant problems of nurseries in the South in 2003. 

Phytophthora root rot,
Phytophthora cinnamomi

Region 8:  North Carolina

Hosts:  Fraser fir, northern red oak

Low levels of Phytophthora root rot were detected in two North Carolina nurseries. Improvement of drainage, removal of infected plant, and fungicides controlled the limited occurrences of this disease.

Rhizoctonia needle blight,
Rhizoctonia sp.

Region 8:  Regionwide

Hosts:  Longleaf pine seedlings

Approximately 65,000 longleaf pine seedlings were killed at the Taylor Nursery in South Carolina by Rhizoctonia in 2003. Although fungicide treatments were made, their efficacy was reduced by rainfall.

Stunt nematode damage,
Tylenchorhynchus ewingi

Region 8:  North Carolina

Host:  Loblolly pine

Stunted 1-0 loblolly pine seedlings were found in several North Carolina fields with an average of 300 stunt nematodes per 100 cc of soil. Fumigation was found to reduce populations but did not eradicate the nematode. The use of non-host cover crops is being investigated as a strategy to help control this nematode.

 

Animal Damage

Beavers

Region 8:  South Carolina

Host(s): various

The South Carolina Forestry Commission reports significant beaver damage to forest trees throughout the State. All forty-six counties reported at least some losses. Most damage was to hardwoods, and the Commission estimates 10,795 acres are affected, representing 194,310 cords valued at nearly $3.5 million. New mortality due to beaver impoundments doubled from 2002 levels, due in part to increased precipitation.  Tennessee reported scattered beaver damage to river birch in Campbell County in the upper Cumberland Plateau.

Voles

Region 8:  Tennessee

Host(s): Loblolly pine, sawtooth oak

Tennessee reported vole damage to sawtooth oak and loblolly pine seedlings in the central portion of the state. Squirrels removed bark from white oaks in northeastern Tennessee; this injury is known colloquially as “squeaver” damage, as the animals “look like squirrels but chew like beavers.”

 

Invasive Exotic Plants

Cogongrass,
Imperiata cylindrical

Region 8:  Alabama, Florida, Georgia, Louisiana, Mississippi, South Carolina, Texas

Cogongrass has gained increased attention for its impact on natural and silvicultural systems. Large infestations in northwest and central Florida are impacting reforestation, seedling survival, wildlife habitat, and timber management. Large infestations in Mississippi are impacting forested areas prompting the establishment of an aggressive control program on both private and public lands. Other states are also experiencing growing problems with this species.

Giant Asian Dodder,
Cuscuta japonica

Region 8:  Texas

Hosts:  Various, host range undetermined

A single occurrence of this plant remains in Houston; all other known sites were eradicated in 2002. As of 2003, this infestation remains uncontrolled, but no new infestations have been detected.

Japanese climbing fern,
Lygodium japonicum

Region 8:  Alabama, Florida, Georgia, Louisiana, Mississippi

The return of normal precipitation levels in 2003 concurred with a significant increase in reports of japanese climbing fern occurrence in central and northern Florida. The spore-related dispersal of both invasive species of Lygodium is raising concerns over the spread of this plant through movement of contaminated persons, equipment, and forest products. The impact on the Florida pine straw industry is of particular concern.

Melaleuca,
Melaleuca quinquenervia

Region 8:  Florida

The non-native forest canopy affecting much of south Florida for the past 70+ years has been significantly influenced by the release of two insect biological control agents which target the invasive melaleuca tree. The impacts of the melaleuca weevil, Oxyops vitiosa (released in 1998) and the melaleuca psyllid, Boreioglycaspis melaleucae (released in 2002) on flowering and new growth have become visibly apparent throughout south Florida.

Old World climbing fern,
Lygodium microphyllum

Region 8:  Florida

Biannual surveys of Old World climbing fern conducted by the South Florida Water Management District indicate population expansion from 27,000 infested acres in 1993 to 109,000 infested acres in 1999. Expansion has continued through 2003, with affected communities ranging from cypress domes to pine flatwoods across central and south Florida.

 

Abiotic Damage

Drought

Region 8:  Regionwide

Hosts:  All species

The protracted drought of 1998-2002 was replaced by a period of abundant precipitation throughout the region. Virginia reported a record wet year, and most states reported fully recharged reservoirs and groundwater tables. South Carolina reported decline and mortality in trees of all species in low-lying areas.

Fire

Region 8:  Regionwide

Aerial surveys in South Carolina found fire mortality on 6,910 acres, with a loss of 124,380 cords of timber worth over $2.2 million.

Air pollution

Region 8:  Tennessee

Tennessee reported moderate ozone damage in the central part of the state and on the Cumberland Plateau.

Wind

Region 8:  Tennessee, Virginia

Twenty-five tornados struck Tennessee in 2003, affecting all parts of the state, with the eastern part of the state most heavily damaged. Urban forest damage was reported from Madison, Dyer, Shelby, and Henderson Counties, while reported rural woodland loss estimates included 100 acres in Williamson County, 500 acres in Coffee County, and 300 acres in Lincoln County. Eastern North Carolina took the brunt of Hurricane Isabel on September 18, with damage spread across 26 counties. Estimates included 833,192 acres of damaged timber with a total value of $565,943,042. Virginia reported major wind damage from Hurricane Isabel and several tornados; both wind and hail damage were severe. Total timber losses from the hurricane were estimated at $176,760,303 across 20 counties.

Ice

Region 8:  Regionwide

Little ice damage was reported across the region in 2003.

Saltwater intrusion/subsidence/erosion

Region 8:   Louisiana

In addition to the detrimental effects of defoliating insects (see forest tent caterpillar and bald cypress leafroller entries), erosion, subsidence, and lack of sedimentation plague the Louisiana coastal wetlands resulting in widespread mortality, particularly of cypress-tupelo stands. Thousands of acres have been lost and more are being lost annually. National attention is increasingly being focused on this issue and a number of projects are attempting to mitigate and reverse conditions leading to loss of forested wetlands and marshlands.

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