2001 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
• Status of Forest Insects
• Status of Forest Diseases
• Seed and Cone Insects and Diseases
• Nursery Pests
• Other Stressors
• Link to The Health of Southern Forests

Most Significant Conditions in Brief

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Drought continued to be a significant stress factor across much of the region in 2001, although rainfall across Arkansas, Texas, and northern Florida in the second half of the year began to ease moisture deficits in these areas. By December, standing water could be found in roadside ditches in Florida for the first time in four years. The region experienced no continental hurricanes in 2001, although tropical storms contributed to water table recharge in Texas and Florida. Other storm damage was scattered and relatively light.

The southern pine beetle epidemic in the Southern Appalachians, the Piedmont of Alabama and the Carolinas, and northern Florida continued to cause serious losses, fueled both by lingering drought and by the sheer weight of beetle population numbers. The Appalachian epidemic included unusual attacks on red spruce, eastern hemlock, and even eastern red cedar. The Florida epidemic was especially costly in urban and suburban landscapes, where both the high property value of the infested trees and the expense of removing them in the proximity of streets, utility lines, homes, and other structures made control efforts difficult. In the Southern Appalachians, depressed softwood markets prevented salvage and sanitation harvesting from being used as a control strategy in many areas.

The red oak borer epidemic and associated oak decline and mortality in north central Arkansas astonished entomologists and alarmed the general public with its intensity and severity. The worst previous attacks seen by this insect had produced infestations of no more than five borers per tree; the current outbreak has produced attacks reaching levels of five borers per square foot of tree bark surface. Degrade from larval galleries rendered much of the timber worthless except as fuel wood. Although some connection to the protracted regional drought appears likely, no direct cause for the unprecedented expansion of the borer population has been discovered.

Gypsy moth populations in Virginia made a sudden move southwestward by some 50 miles into previously non-infested territory. This event was the result of a combination of the existence of several small isolated populations in advance of the primary edge of the infestation and the occurrence of nearly two weeks of strong northeast winds at the time of first instar moth larval “balooning.” This unusual spring weather carried larvae well forward of the infestation front, and raised concerns over a possible failure of the current “slow-the-spread” strategy. Declining influence of the Entomophaga maimaiga fungus on moth populations, believed to be the result of the suppressing influence of dry weather on fungal growth, also accelerated the growth of moth populations. 

Hemlock wooly adelgid populations also made a dramatic move southwestward through North Carolina and into upstate South Carolina. This expansion puts both native hemlock species at risk of rapid extirpation throughout most of the Southern Appalachian region, with serious ecological consequences.

Status of Forest Insects

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• Baldcypress Leafroller
• Black turpentine beetle
• Buck moth
• Fall cankerworm
• Forest tent caterpillar
• Giant bark aphids
• Nantucket pine tip moth
• Oak leaf tier
• Pine colaspis beetle
• Pine engraver beetle
• Pine sawflies
• Red oak borer
• Reproduction weevils
• Southern pine beetle
• Texas leaf-cutting ant
• Truncated true Katydid
• Variable oak leaf caterpillar
• Asian longhorned beetle
• Balsam woolly adelgid
• Gypsy moth (European)
• Hemlock woolly adelgid
• Pink hibiscus mealybug

Baldcypress Leafroller,
Archips goyerana (formerly reported as fruittree leafroller, A. argyrospila)

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Louisiana

Hosts: Baldcypress

In 2001, 110.000 acres of mixed baldcypress stands in southern and southeastern Louisiana were defoliated by the baldcypress leafroller. Approximately 53,000 acres were severely defoliated (>50%). The predominant impact of this defoliation is loss of radial growth, although dieback and scattered mortality occurred in some areas in Assumption, St. James and St. Martin Parishes. Permanently flooded areas are most severely impacted.

Black turpentine beetle,
Dendroctonus terebrans

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Regionwide

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

Again in 2001, summer drought throughout the eastern South resulted in higher-than-normal black turpentine beetle activity.  Areas of exception were Mississippi, Tennessee and Texas. In West Tennessee, populations were notably lower than last year. In Georgia, some of the most intense activity was noted in thinned loblolly plantations. This insect is most evident in trees stressed by drought, logging injury, root compaction, and similar disturbance. 

Buck moth,
Hemileuca maia

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Louisiana and Virginia

Hosts: Live oak and other hardwoods

Buck moth defoliation of live oak has been a problem in New Orleans for a number of years. It continues to be locally abundant in the city and of particular concern in the Federal Historic Districts. The insect population was found to be decreasing in 2001; pheromone trapping recovered only 1.3 moths/trap as compared to 2.8 in 2000. In Virginia, populations routinely fluctuate considerably, and were at locally high densities in 2001.

Fall cankerworm,
Alsophila pometeria

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Tennessee, North Carolina and Virginia

Hosts: Various oak species

In East Tennessee, the fall cankerworm, in association with the green fruitworm and oak leaf tiers, defoliated about 200 acres of upland hardwood in Monroe County. Additional defoliation was reported in two counties near Knoxville. In North Carolina, populations in the Charlotte area, consistently very heavy in recent years, were low in 2001. Likewise, Virginia populations were relatively low in 2001.

Forest tent caterpillar,
Malacosoma disstria

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Louisiana, North Carolina, South Carolina and Texas

Hosts: Tupelo gum, upland hardwoods

Defoliation occurred on 112,000 acres of forested wetlands in Ascention, Livingston, St. James and St. John Parishes in southeastern Louisiana. This defoliation was severe (50%) on 38,000 acres. In North Carolina, 40,000 acres were defoliated along the Roanoke River, with 500 acres classified as “heavily defoliated.” In South Carolina, 169,000 acres were again defoliated in 2001 in the Congaree, Santee, Pee Dee, and Wacamaw River basins. 

Giant bark aphids,
Longistigma caryae

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Texas

Hosts: Oaks

In December 2001, an unusual outbreak of the giant bark aphid began across most of East Texas and persisted into 2002. This aphid is known to occur in the eastern half of the U.S. and is the largest aphid in North America. The aphids are primarily feeding on oak trees and seem to favor water and live oaks. Aphids suck plant juices and excrete large quantities of honeydew, a clear, sticky, sugary liquid. An unsightly gray-black sooty mold often grows on the honeydew. Even with large numbers of aphids present, their feeding is not expected to cause serious harm to the trees.

Nantucket pine tip moth,
Rhyacionia frustrana

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Regionwide

Hosts: Loblolly pine, shortleaf pine

Tip moth problems were noteworthy in Virginia, North Carolina, Tennessee, and South Carolina.  North Carolina infestations were classified as “moderate” this year. Consistent with last year’s report, Virginia populations seem to have evolved into a persistent problem in the coastal plain and piedmont. South Carolina populations were again high, especially in 3-5 year-old plantations on old agricultural sites. About 8,500 acres in South Carolina were reported infested, with some areas exhibiting 100% infestation rates.  In Tennessee, an unusual fourth generation was reported in the north-central part of the state. Significant damage was also reported from West Tennessee on loblolly pine seedlings. Mississippi experienced large acreages of tip moth damage in Grenada and Holmes Counties. Infestation levels in Texas have been static since 1999, with some isolated areas having as much as 75% tip infestation.

Oak leaf tier,
Croesia semipurpurana

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Florida, Tennessee

Hosts: various oak species

In Florida, a March outbreak of the oak leaf tier in two heavily people-populated areas (St. Petersburg and Deland) caused extensive defoliation. While there appears to be no significant harm to the trees, concern by the public generated many calls to extension service and state forestry agency personnel. As noted above, oak leaf tiers were also a component of a multi-species defoliator outbreak in East Tennessee.

Pine colaspis beetle,
Colaspis pini

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Regionwide

Hosts: Southern pines

This beetle caused localized defoliation to pine plantations in central Louisiana, particularly eastern Rapides Parish, in 2001. No significant damage occurred, but defoliation is unsightly, causing landowner concerns.

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

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Regionwide

Hosts: Loblolly pine, shortleaf pine, slash pine

Another year of drought contributed to high populations of Ips beetles throughout much of the region. The heaviest impact was in Florida, Southeast Georgia, and South Carolina. Florida losses again were exceptionally high compared to the norm, and were often associated with other stress factors such as overstocking, root compaction, and poor soils.  In South Carolina, Ips infestations were often associated with southern pine beetle (SPB), and Ips spots were at first often mis-identified as SPB infestations during aerial surveys. Ground checks proved otherwise. North Carolina infestations were worst in the mountains, foothills, and western piedmont, especially on dry sites. As in South Carolina, infestations were often mixed in with southern pine beetle. Virginia reported slightly elevated population densities in 2001. Nevertheless, Tennessee witnessed a noteworthy decline in Ips populations, especially in the middle part of the state, where abundant rainfall apparently helped increase stand vigor and resistance to beetle attack. Poulations also declined somewhat in Louisiana, with 48 large multiple-tree spots detected. In addition, hundreds of single-tree or small spots were scattered across the state. Very low levels of engraver beetle activity were reported in Mississippi, and levels in Arkansas and Texas dropped dramatically from 2000 with a return to more normal rainfall.

Pine sawflies,
Neodiprion sp., Diprion sp.

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Arkansas, Florida, Louisiana, Mississippi, North Carolina, Tennessee, Texas,Virginia

Hosts: Southern pines

Populations of the loblolly pine sawfly (Neodiprion taedae linearis) were up in southern Arkansas with heavy defoliation in parts of Brady, Calhoun, Dallas and Union Counties. Tennessee noted that populations of this species increased in scattered areas across the north-central part of the state, but were at lower levels than reported in 2000 in the west. Black-headed sawflies (N. excitans) defoliated a 60-acre tract in George County, Mississippi, and there were occasional reports from other areas of that state. Defoliation declined significantly in Louisiana, with only scattered occurrences reported from older plantations in Caldwell, Jackson, LaSalle and Winn Parishes. In North Carolina, there were several reported outbreaks of this species in northeastern counties in 12-20 year-old pine plantations. Florida recorded another year of redheaded pine sawfly (N. lecontei) activity, but infestations were far less significant compared to those of the year 2000. Most damage again occurred in young (<15 years) longleaf and slash pine plantations. Tennessee also reported scattered, but increased populations of the redheaded pine sawfly across the state. In the North Carolina mountains , there were drought related outbreaks of Diprion similis, the introduced pine sawfly.

Red oak borer,
Enaphalodes rufulus

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Arkansas, South Carolina, Georgia

Hosts: Northern red oak, black oak

Red oak borer attacks continued at extremely high levels in 2001 in north central Arkansas in association with oak decline initiated by severe drought in 1998-2000. Populations are now at unprecedented levels. Damage contributed to drought-related mortality in red oaks, and degrade in lumber from attacked trees sharply reduced product values. Mortality, especially in red oaks, is now at unprecedented levels, and there is great concern about the impacts on oak forests across the state. Red oak borer adults emerged in 2001, and with a two-year life cycle will infest trees until re-emerging in 2003. In central Louisiana, some red oak borer activity was noted in conjunction with oak decline in bottomland hardwoods. The borer attacked red and scarlet oak in the piedmont of South Carolina. In combination with drought stress, it contributed to some mortality. Georgia also reported problems with the red oak borer (and other borers) associated with the drought and trees growing on poor sites.

Reproduction weevils,
Hylobius pales, Pachylobius picivorous

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North Carolina, South Carolina, Texas

Hosts: Southern pines

Weeviling contributed to the loss of 1,050 acres of newly-planted pines in the South Carolina coastal plain. In North Carolina, damage generally remained light to moderate throughout the state, with only limited scattered heavy infestations. Weevil activity remained low in Texas during 2001, probably because most plantings were replantings of stands where seedlings were killed during the recent drought (delayed planting ameliorates weevil damage risk).

Southern pine beetle,
Dendroctonus frontalis

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Regionwide

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

In 2001, southern pine beetle (SPB) populations countinued at very high levels in the Southern Region.  The extended drought exacerbated the SPB situation by providing optimum habitat for this native forest pest.  The outbreak covered portions of Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia on federal, State and private ownerships (map showing counties in southern pine beetle outbreak status).  It will be recorded as one of the largest outbreaks in history.  On the contrary there was not even a single SPB infestation in the entire states of Louisiana, Texas, Arkansas and Oklahoma.  Compared to 2000, the number of SPB infestations in the Southern Region remained virtually constant (60,628 spots to 58,839 spots) as did the number outbreak acres. (chart showing southern pine beetle infestations for 2000-2001 -- text-only data. Also see table below.)

The southern Appalachian Mountain area from southwestern Virginia and southern Kentucky to eastern Tennessee, western North and South Carolina to northern Georgia was devastated.  SPB attacked hosts other than its favored southern yellow pines.  Eastern white pine was commonly killed, and significant infestaions occurred in Norway and red spruce at the higher elevations.  Suppression of individual SPB infestations was limited by poor markets and lack of accessibility.  Many infestations were hundreds of acres in size. 

In Virginia over 270,000 trees killed by SPB in 762 infestations across 15 counties (10 of which were in outbreak status).  Kentucky also reported another very bad SPB year, with 3,513 infestations tallied in 45 counties, 41 of which were in outbreak status.  Most losses were in the drought-ravaged mountains, with impacts greatest on south-facing slopes and shallow soils.  A large number of white pines have also been lost in Kentucky – so much so that the log home industry, and important source of employment in many rural areas, has been severely affected.

In Tennessee, beetle populations began to decline in the Southern Appalachians, but the losses over the past 2 years have been devastating.   More abundant rainfall reversed the three-year pattern of summer and fall droughts.  Nevertheless, there were more spots east of Nashville and north of Knoxville.

In North Carolina, there was a 98% percent increase in infestations over year 2000 (1,951 to 3,871). While activity decreased slightly in the mountains, losses in the western piedmont and foothills more than offset this improvement.  In all, 32 North Carolina counties were infested, with 22 classified in outbreak status  North Carolina foresters and botanists expressed concern about the loss of low population tree species such as table mountain pine and red spruce.  Because of poor markets, only 5% of trees were salvaged. 

In South Carolina, financial loses reached $76 million – the second worst year of financial loses on record.  Most SPB activity was confined to the western piedmont, foothills, and mountains where 19 counties were in outbreak status.  Very poor salvage markets hampered effective control.

Alabama remained a hot spot for beetle activity, the state’s third straight year for epidemic populations. Statewide 11,945 spots were detected statewide with 45 counties considered epidemic. This is a reduction from the record setting 26,407 in 2000, but still is a very level of activity. 

Florida's nightmare year of 2000 actually grew much worse in 2001. The state's problems were compounded by infestations throughout much of the wildland-urban interface (e.g., the Gainesville-Alachua County area) that took the brunt of much of the outbreak. The situation was aggravated by drought and poor salvage markets. Beetle activity and associated problems were so severe, widespread, and intense, that the Florida Commissioner of Agriculture declared the situation an “incident,” and convened a task force to address the problem. Unprecedented infestations occurred in Lake Orange, Seminole, Sumter, and Volusia Counties – none of which had any previous record of SPB infestations. Nine counties in central and northeastern Florida were epidemic, more than twice the number ever previously experienced. In all, Florida recorded 2,892 infestations in 34 counties. Some 3.5 million trees were lost at an estimated cost of $38.4 million.

Georgia reported 28 counties epidemic in the northern part of the state. Inaccessibility and poor wood markets complicated salvage efforts. Georgia recorded 4,863 spots in 2001.

In western Gulf States, beetle populations remained low. Mississippi detected only 137 spots statewide, and no spots were detected in Arkansas, Louisiana, Oklahoma and Texas.

Texas leaf-cutting ant,
Atta texana

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Louisiana, Texas

Hosts: Southern pines and hardwoods

In 2001, localized defoliation of pine plantations occurred in east Texas and west central Louisiana on sites with deep sandy soil. Populations of these ants remain fairly static from year to year. A new ant bait, Volcano®, was registered for use in Texas in 1999 and in Louisiana in 2000 and provides excellent control. A single application can eliminate an ant colony in as little as four weeks.

Truncated true Katydid,
Paracryptophyllus robustus

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Texas

Host: Post oak

In July 2001, about 500 acres of post oak forest in Lee County, Texas were defoliated by an unusual outbreak of the truncated true katydid. Trees suffered little from this defoliation.

Variable oak leaf caterpillar,
Lochmaeus manteo

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Florida

Hosts: oak

In 2001, the variable oak leaf caterpillar again caused thousands of acres of defoliation during July and August in three Florida counties (Gilchrest, Suwanee and Columbia). While there is not evidence of mortality, the damage generated many calls by concerned landowners to extension agents and foresters.

Asian longhorned beetle,
Anoplophora glabripennis

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Texas

Hosts: Hardwoods

An adult beetle was collected inside a warehouse at the Port of Houston in 2000. Intensive surveys of vegetation in the vicinity of the warehouse in 2001 revealed no evidence of infestation. USDA Animal and Plant Inspection Service personnel conduct detailed inspections of wood packing material from China to find and prevent accidental introduction of this unwanted wood boring beetle.

Balsam woolly adelgid,
Adelges picea

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North Carolina, Tennessee, Virginia

Host:  Fraser fir

Fraser fir has a very limited range in the southern Appalachian Mountains (map showing spruce/fir distribution) and appears almost exclusively in pure stands on the highest mountain peaks or in combination with red spruce at somewhat lower elevations.  Since the first introduction of the balsam woolly adelgid, approximately 64,700 acres of Fraser fir have been affected.  The insect attacks trees of all age classes, but prefers the older fir trees.  Adelgid populations were again high in 2001.

Gypsy moth (European),
Lymantria dispar

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Arkansas, Georgia, North Carolina, Tennessee, Virginia

Hosts: Hardwoods, especially oak species

In 2001, aerial surveys detected over 440,000 acres of defoliation by gypsy moth in Virginia (map showing gypsy moth defoliation area).  Populations were highly variable due in part to continued drought, the effects of an Entomophaga maimaiga fungal outbreak and the gypsy moth nucleopolyhedrosis virus.  Gypsy moth populations noticeably increased in the central and eastern portions of the State.  Virginia Department of Agriculture and Consumer Services (VDACS) conducted aerial suppression activities on approximately 35,000 acres in 2001.  With the increase in populations in 2001, the potential for defoliation is greater next year.  Treatments are planned for approximately 65,000 acres in 2002. 

2001 trapping information in North Carolina revealed no new infestations.  Delimiting trapping of the pheromone flake eradication blocks treated in 2000(Clay, Jackson, and McDowell counties in western North Carolina) caught several single moth captures in each of the blocks.  Final delimiting trapping for these blocks will be completed in 2002.  No moths were captured in 2001, the final year for the delimiting trapping of the 23,000- acre pheromone flake eradication treatment (1999) in and around Highlands, NC and a portion of Georgia.  North Carolina has no treatments planned in 2002. 

In Tennessee, two more counties have been added to the list of infested counties (Monroe and Campbell) making a total of 5 infested counties in the State (Scott, Cumberland, Sevier, Monroe and Campbell).  As a result of an increase in trap captures, an aerial treatment is proposed for Campbell county (8,500 acres) and ground treatments are proposed for Monroe and Scott counties in 2002.  Follow-up trapping will continue in Cumberland and Scott counties where ground treatments were conducted in 2001. 

In Arkansas, delimiting trapping was successful in eradicating moths from Carroll and Marion counties in 2000. Delimiting trapping in Newton County caught 3 moths in a single trap.  The 80 square mile detection trapping area surrounding the delimiting area revealed no trap catches.  As a result of the trapping in 2001, this area will be reduced, in 2002, to cover a 5 square mile area for delimit trapping. Additional detection trapping across the state produced four moths near Mountain View in separate traps, two were caught near Hot Springs, and two near Camden. No treatments are planned. 

The Slow the Spread Project (STS) conducted aerial treatments in seven states.  Within the boundaries of the Southern Region, 1,200 acres were treated in eastern North Carolina and 65,000 acres were treated in eastern and western Virginia.  STS treatments are planned for Virginia in 2002; however, no treatments are planned for North Carolina.

Hemlock woolly adelgid,
Adelges tsugae

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North Carolina and Virginia

Hosts:  Eastern and Carolina hemlock

Populations of the hemlock woolly adelgid (HWA) increased alarmingly in 2001 (map showing hemlock woolly adelgid occurrence by county -- text-only data). This insect threatens the entire range of eastern hemlock, and is found throughout Virginia wherever hemlock is abundant with the exception of 6 counties in the southwestern portion of the state. In North Carolina, eleven new counties were reported infested with the HWA in 2001—Ashe, Burke, Caldwell, Graham, Jackson, Macon, Mitchell, Swain, Watauga and Yancey—constituting a major population movement southwestward. An established population was also found in Oconee County, South Carolina near the Chattooga River, and infestations are believed to already be established in neighboring Rabun County, Georgia. Because of the strong influence of spring northward-migrating songbirds in spreading this insect, the entire range of Carolina hemlock (Tsuga caroliniana) is now at risk, and this species could be extirpated from the wild within as little as five years. Eastern hemlock (T. canadensis), an important riparian and midle-elevation wildlife habitiat component, is also now at risk of extirpation throughout the Southern Appalchians.

Pink hibiscus mealybug,
Maconellicoccus hirsutus

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Puerto Rico, Virgin Islands

Hosts:  Hibiscus and many other species

The pink hibiscus mealybug (PHM) continued to spread in 2001, and has now reached over two-dozen Caribbean Islands.  It was detected in Puerto Rico in 1997, but has been confined to the eastern region.  Frequent monitoring surveys are conducted, assisted by the Digital Arborist.  To date, no infestations have been identified on the Caribbean National Forest.  It appears that parasitoids may have been introduced simultaneously with the mealybug, reducing the impacts in Puerto Rico.  With support from the Digital Arborist and Animal and Plant Health Inspection Service, the Puerto Rico Department of Agriculture continues to rear and release parasitoids.  Surveys continue to show that population reductions of 85-90 percent have been achieved at the parasite release sites.  Because of the large number of known host species in Florida, extension agents continue to carefully monitor for this pest. Fortunately, the PHM has not been detected there.  

Status of Forest Diseases

• Annosus root disease
• Fusiform rust
• Littleleaf disease
• Oak wilt
• Beech bark disease
• Dutch elm disease
• Butternut canker
• Dogwood anthracnose
• Pitch canker
• Oak decline

Annosus root disease,
Heterobasidion annosum

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Regionwide (map showing annosus hazard rating)

Hosts: Southern pines

In Georgia, annosus root disease has increased throughout the state on high hazard sites in older Conservation Reserve Program (CRP) plantations that have been thinned. Similarly in South Carolina, annosus was troublesome on CRP sites, with 17 industrial landowners requesting evaluations by the South Carolina Forestry Commission in 2001. The Commission recommended clearcutting and replanting 1,500 acres.

Fusiform rust,
Cronartium quercuum f. sp. fusiforme

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Regionwide

Hosts: Southern pines, especially loblolly and slash pines

Fusiform rust is the most damaging disease of loblolly and slash pine in the South. Other pine species may also be infected, but little damage or mortality occurs.  An estimated 13.8 million acres of loblolly and slash pine have at least 10 percent of the trees infected. Georgia is the most heavily impacted state, with 4.6 million acres (49 percent of host type) affected.  Exceptionally dry weather over much of the eastern South over the last 2-3 years should have resulted in lower-than-normal levels of new infections in young pines, but slow symptom development has prevented verification of this effect.

Littleleaf disease,
Phytopthora cinnamomi

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Virginia, North Carolina, South Carolina, Georgia, Alabama, Tennessee, Kentucky

Hosts: Loblolly and shortleaf pines

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 their age of susceptibility.  These stands are often attacked by bark beetles after being 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. 

Oak wilt,
Ceratocystis fagacearum

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North Carolina, Tennessee, Virginia

Hosts: Live and red oaks

Oak wilt continues to be a devastating tree killer in 60 central Texas counties. Urban, suburban and rural oaks are affected. Live oak is a premier shade tree species in the region and is highly valued for beauty, shade and wildlife benefits. The Texas Forest Service completed a fourteenth year of cooperative suppression of the disease. Since this project’s inception, more than 2.7 million feet (>525 miles) of barrier trenches have been installed on more than 2,000 oak wilt infection centers in 34 counties. Oak wilt foresters with the Texas Forest Service conducted aerial surveys for oak wilt infection centers over about 658.400 acres in central Texas in 2001.

There was mixed oak wilt activity in the eastern South in 2001. Aerial surveys in Tennessee showed no activity at all in the Cumberland Plateau (Cumberland, Putnam, and White Coutnies). In North Carolina too, activity was down markedly. The North Carolina Division of Forest Resources reported 20 oak wilt infection centers involving 24 trees in Buncombe and Haywood Counties in the mountains. In contrast, Virginia reported a slight increase in oak wilt-causd mortality.

Beech bark disease,
Nectria coccinea var. faginata

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North Carolina, Tennessee, Virginia

Hosts:  American beech

Beech bark disease was not found in any additional counties in 2001, but the disease continues to intensify within currently affected areas (map showing beech bark disease occurrence by county -- text-only data). Tree mortality continues to intensify in Tennessee along the Appalachian Trail and in Blount, Cocke, and Sevier Counties within the Great Smoky Mountains National Park. The disease has intensified at a faster rate than predicted, and is spreading downslope toward the Cherokee National Forest.

Dutch elm disease,
Ophiostoma ulmi

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Regionwide

Hosts: American elm

Localized mortality continues to occur at low severity level in urban and wild populations of elm. North Carolina reported a number of scattered incidents of the disease in 2001.

Butternut canker,
Sirococcus clavigigenti-juglandacearum

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Regionwide

Hosts: Butternut

This disease 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 (map showing butternut canker occurrence by county -- text-only data). 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.

Dogwood anthracnose,
Discula destructiva

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Alabama, Georgia, Kentucky, North Carolina, South Carolina, Tennessee and Virgina

Host: Flowering dogwood

While no new counties were reported infected in the eastern portion of the South in 2001 (map showing dogwood anthracnose occurrence by county -- text-only data), South Carolina and North Carolina report increased mortality caused by dogwood anthracnose (DWA) in previously infected areas. North Carolina impact plots established in 1981 now show an average of 56% DWA-caused mortality. Further west, Logan County, Kentucky was reported as a new infection site.

Pitch canker,
Fusarium subglutinans f. sp. pini

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Regionwide

Hosts: Southern pines

Only scattered trees across the Region are infected, but impacts can be locally significant.  In Georgia, and South Carolina, pitch canker continues to be associated with pine plantations near chicken and turkey houses.  The ammonia released from the brood houses creates conditions on the trees conducive to infection. The damage is usually confined to the area within the plantation nearest exhaust fans.  All species of pine (slash, longleaf, and loblolly) are affected.  Poultry houses are becoming a common sight throughout the coastal plain of Georgia.  Thus, problems with pitch canker are expected to increase, especially during droughts.  Similar problems have been noted in North Carolina when chicken waste has been used as fertilizer in pine plantations. In Texas, about 10 percent of the cone crop in state seed orchards was affected by pitch canker in both 2000 and 2001.

Oak decline, abiotic and biotic influences

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Regionwide

Hosts: Oaks, other hardwoods

The severe summer drought of 1998- 2000 continued into 2001.  Oak decline was severe in the southern Appalachian Mountains, with North Carolina and Virginia incurring heavy losses on south-facing slopes.  Similarly, Tennessee noted increased loss of both red and white oak, with white oaks especially hard hit.  In Georgia, oak mortality was heaviest on rocky ridges and side slopes in the mountains.  Drought is just one component of oak decline, a syndrome resulting in dieback and mortality of dominant and co-dominant mature oaks.  Other causal factors including frost, defoliation by insects (including the gypsy moth), secondary pests such as Armillaria root disease and two-lined chestnut borer, and Hypoxylon canker.  Oak decline and gypsy moth have been shown to interact: severe defoliation by gypsy moth can induce oak decline in previously unaffected areas; and, in areas of pre-existing oak decline, defoliation by gypsy moth causes increased mortality.  Host tree age and site conditions also play a role.  Oak decline is on the rise in Tennessee, but at a lower rate of increase than in 2000. This syndrome is believed to have caused 2% mortality in some southwest Tennessee counties. Impact in 2001 was exacerbated by drought, which caused its greatest impact on dry, south-facing slopes. The syndrome is frequently associated with Hypoxylon canker, especially in western and middle Tennessee.

Drought initiated oak decline of unprecedented magnitude in Arkansas. Particularly impacted were the Ozark and Ouachita Mountains, where widespread red oak mortality occurred, aggravated by red oak borer activity (see Native Insects, Red oak borer). Mortality levels will have severe impacts on oak ecosystems; and are having severe impact on oak sawtimber markets.

Seed and Cone Insects and Diseases

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

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Regionwide

Hosts: Southern pines

In 2001, coneworms continued to cause significant losses to improved seed crops in southern orchards, primarily loblolly pine.  In central Louisiana, a bumper crop of longleaf pine cones was harvested; however, inventory samples revealed that 63% of cones infested with and destroyed by coneworms.  Much of this loss occurred between May and July indicating substantial attacks on maturing cones likely due to D. amatella.  Other samples taken from loblolly orchards in Florida, Texas and Louisiana indicated losses of 15-70% from coneworm. Losses in unspraed orchards in Texas remained static at about 35-45%. Losses in treated orchards were considerably less.

Seedbugs,
Leptoglossus corculus, Tetyra bipunctata

Regionwide

Hosts:  Southern pines

Both species of seedbug were abundant in southern pine seed orchards.  Inventory samples indicated that seedbugs caused about 25% seed loss in untreated orchards. In Tennessee, successful control efforts reduced losses to seedbugs to only 10 pounds of infested seed in 2001.

Pine seedworm,
Cydia spp.

Regionwide

Hosts: Southern pines

Inventories of longleaf pine in Central Louisiana revealed low, but consistent, seedworm populations.  Estimated loss was 2-3% of seed.

Pine catkin sawfly,
Xyela spp.

Louisiana, Texas

Hosts: Southern pines

An unusual outbreak of this small and seldom seen insect occurred in the spring of 2001 on loblolly pine in central Louisiana and extreme eastern Texas.  An unusually large male flower (catkin) crop likely contributed to the outbreak.  Infestations of mature larvae were observed at orchards and in private yards under infested trees.  Although very abundant, the impact on pollination was likely insignificant.

Southern cone gall midge,
Cecidomyia bisitosa

Florida

Hosts: slash pine

For a third consecutive year, infestations of southern gall midge caused significant losses on an industrial seed orchard in Nassau County, Florida. Infestation rates did decline however, from 55% of first year conelets in 2000 to 35% in 2001 based on the average of samples taken from identical ramets of susceptible clones.

Nursery Pests

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Rhizoctonia needle blight,
Rhizoctonia sp.

Regionwide

Hosts:  Longleaf pine seedlings

Losses were reported from North Carolina in 2001, but not at abnormal levels.  Over 50,000 seedlings were lost to this disease in 2001 in South Carolina’s Taylor State Tree Nursery.

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

Regionwide

Hosts: various species

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 (species of Fusarium, Pythium, Rhizoctonia, and Phytopthora) and environmental conditions. Seedling losses can be severe when germination is slow due to cold, wet weather. Losses in 2001 were lower than normal due to the very dry weather which inhibits fungus development.  Fusarium and/or Phytopthora root rot caused 5-10% losses os sawtooth and Shumard oak in West Tennessee in 2001 (a post-emergence problem). In Virginia, Phomopsis continues to be a problem on eastern red cedar in Virginia nurseries.

Other Stressors

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Drought

Regionwide

Hosts: All species

Drought conditions prevailed over much of the eastern South for the fourth consecutive year.

Georgia suffered continued drought-caused tree losses. Impacts in nurseries were again severe, with heavy loss of containerized seedlings recorded.

Florida witnessed another year of stress related pest activity and associated tree death/damage. Impact in Florida was especially intense in the northeast. Among the secondary insects and diseases proliferating in the weakened trees were Ips beetles, black turpentine beetle, redheaded pine sawfly, Kermes scale, two-lined chestnut borer, ambrosia beetles, southern pine root weevil (Hylobius aliradicus), and Hypoxyloncanker.

Similar problems occurred in South Carolina where the state recorded its third consecutive

20-inch rainfall defecit year.

Much like last year, North Carolina reported a host of drought-related problems, especially in the mountains, foothills, and western Piedmont. Similarly, Virginia continued to experience drought problems with forests and trees across the Commonwealth.

Drought was less intense in Tennessee in 2001 than in the previous three summers, but the cumulative stress continued to cause mortality in the oak/hickory forest type.

Drought abated over much of the western Gulf region in 2001. This may have contributed to a lessening of drought-initiated dieback and decline in susceptible trees.

Fire

Regionwide

Hosts:  All species

For the fourth year in a row, fire (both wildfire and prescribed burns) generated a high incidence of tree mortality in Florida, which was further aggravated by the drought. Besides outright fire-caused mortality, many trees succumbed to secondary insects and diseases that exploited the trees’ fire-weakened condition. 

North Carolina reported 27,859 acres burned, much of it from October through December.

Tennessee reported 35,000 acres burned in the eastern part of the state. Many of these fires were arsonist-set in October and November and affected primarily upland hardwoods.

Air pollution

Tennessee

Hosts: all species

Ozone damage was very evident in the Cumberland Plateau and the Knoxville area of Tennessee in 2001.

Frost

Tennessee

Hosts: various species

Scattered frost affected elm, hackberry, sycamore and cottonwood were reported from upper-middle Tennessee. Severe frost damage in west and upper middle Tennessee caused reduced acorn crops, with corresponding negative impact on wildlife species dependent on acorns for food.

Wind

Tennessee, Virginia

Hosts: Southern pines and hardwoods

Winds toppled dead pines onto houses north of Knoxville and uprooted hardwoods in middle Tennessee. One wind storm swath affecting Coffee and Franklin Counties was 200 feet wide and three-quarters of a mile long. Tornado caused damage was reported in Henry County in West Tennessee.

In Virginia, high winds in combination with hail and flash floods affected Southwestern Virginia in May and July.

Ice

Arkansas, Oklahoma, Texas

Hosts: Southern pines and hardwoods

Although no significant new ice storms hit the South in 2001, assessment and clean-up of the Christmas 2000 storms across Arkansas, Oklahoma and Texas continued through early 2001.

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