USDA Forest Service
Pacific Southwest Region
Forest Pest Management
A Publication of the California Forest Pest Council
Forest Pest Conditions in California 1995
_____________________________
Contents
(return to publications page)
The California Forest Pest Council
The California Forest Pest Council (formerly the California Forest Pest Control Action
Council) was founded in 1951. Membership is open to public and private forest managers,
foresters, silviculturists, entomologists, pathologists, biologists, and others interested
in the protection of forests from damage caused by animals, diseases, insects, and weeds.
The council's objective is to establish, maintain, and improve communication among
individuals managers, administrators, and researchers who are concerned with
these issues. This objective is accomplished by four actions:
- Coordination of detection, reporting, and compilation of information on forest insects,
diseases, and animal damage.
- Evaluation of conditions centered upon forest insects, diseases, and animal damage.
- Control recommendations made to forest managing agencies and landowners.
- Review of policy, legal, and research aspects of forest pest control, and submission of
recommendations thereon to appropriate authorities.
The California Board of Forestry recognizes the Council as an advisory body in forest
health protection. The Council is a participating member in the Western Forest Pest
Committee of the Western Forestry and Conservation Association.
The report, Forest Insect and Disease Conditions in California 1995,
is compiled for public and private forest land managers and other interested parties to
keep them informed of conditions on forested land in California, and as an historical
record of forest insect and disease trends and occurrences. The report is based largely on
information provided by three sources:
- the state-wide Cooperative Forest Insect and Disease Survey, in which federal, state,
and private foresters and land managers participate,
- information generated by Forest Pest Management, Pacific Southwest Region, USDA-Forest
Service, while making formal detection surveys and biological evaluations,
- reports and surveys of conditions on private lands provided by personnel of the
California Department of Forestry and Fire Protection, and
- surveys and detections of the California Department of Food and Agriculture.
This report was prepared by the U.S. Forest Service and the California Department of
Forestry and Fire Protection, and published and distributed by the California Department
of Forestry and Fire Protection in cooperation with the Council's Standing Committees.
Allen Robertson, Editor-in-Chief
Steve Jones, Editorial Committee Chair
________________________________
Back to Contents
Executive Summary
Bark Beetles
Tree mortality caused by bark beetles continued in the east side forests of the
northern Sierra Nevada and southern Cascade ranges in spite of the wet winter of 1994-95.
Fir engraver beetle on true firs and Jeffrey pine beetle on Jeffrey pine accounted for
much of the mortality. Western pine beetle caused mortality of ponderosa pine in some
portions of this region and in the Sacramento River Canyon and along the Trinity River
north of Trinity Lake. The mountain pine beetle continued to kill sugar pine scattered
throughout northern California and was common in ponderosa and lodgepole stands from
Lassen County southward to El Dorado County. It also killed some lodgepole pines damaged
by needleminers in the Stanislaus National Forest and Yosemite National Park. The
Douglas-fir beetle remained at low levels. Other bark beetles and wood borers were common
associates of the more damaging bark beetles.
Defoliators
The recent outbreak of white fir sawfly in Lassen County collapsed. Tent caterpillar
was prevalent on bitterbrush from northern Lake Tahoe into the southern portion of the
Southern Cascades ecoregion. Lodgepole pine needleminer caused moderate to high
defoliation over 8,000 to 10,000 acres of the Stanislaus National Forest and Yosemite
National Park. A new species of Timema defoliated Douglas-fir in Humboldt and Mendocino
County. Defoliation by the Douglas-fir tussock moth was not observed, but trap catches are
markedly up in some parts of the central and norther Sierra Nevada ecoregion and the Modoc
Plateau. Similar increases preceeded the last outbreak in California by two to three
years.
Pine pitch canker
The disease continues to spread to new areas and is now reported from 14 coastal and
adjacent inland counties, from San Diego to Mendocino. With the report of the disease at
Cambria, the pathogen is now present in all three of California's native Monterey pine
stands.
Port-Orford-cedar root disease
Phytophthora lateralis was reported for the first time in native stands of
California outside of the Smith River watershed. The pathogen has been identified in one
area, at the headwaters of Potato Patch Creek, which is part of the Klamath River
watershed. Signs and symptoms indicate that the disease has been present at the site for
about 2 years.
White pine blister rust
The introduced pathogen Cronartium ribicola continues to be reported on sugar
pine at new locations, and is spreading into high elevation white pine ecosystems, being
reported on: foxtail pine, at Lake Mountain on the Klamath National Forest; on western
white pine, from the south fork of Cold Creek (4 miles south of Donner Lake) up to the
Pacific Crest Trail; and on western white pine, at 7,500 foot elevation, on the Lake Tahoe
Basin.
Animal damage
A variety of mammal species have caused damage to forest trees. The damage varies by
region of the state and by land ownership. All of California's major timber producing
regions and timber types have reported damage by vertebrate species. Species most commonly
identified as causing problems weer deer, pocket gopher, domestic stock, rabbits and
hares, porcupine, woodrat and black bear.
_______________________________________________
Back to Contents
Status and Control of Insects
A Report to the Forest Pest Council from the Insect Committee
Bruce Roettgering, Chair Laura Merril, Secretary
WESTERN PINE BEETLE, Dendroctonus brevicomis
- M261B - Northern California Coast Ranges
- Scattered attacks by western pine beetle and flatheaded borers were noted in Lake County
near Cobb.
- M261A - Klamath Mountains
- Although the winter of 1994-95 was very wet as a whole, the month of February was very
clear and dry, and large ponderosa pine began to fade in northwestern California during
the month of February. These trees were attacked during the summer or fall of 1994, which
was extremely dry. Areas where early fading of larger ponderosa pine was evident included
the Sacramento River canyon from Lakehead to Dunsmuir, the upper Trinity River above Clair
Engle Lake, along the Highway 299 corridor from Buckhorn Summit west to Douglas City, and
around the Hayfork Valley.
- Western pine beetle was the most common bark beetle associated with scattered ponderosa
pine mortality in Greenhorn Park, Siskiyou County. Associated beetles included the
mountain and red turpentine beetles.
- M261B - Northern CA coast ranges.
- There was some ponderosa pine mortality observed by aerial survey in the extreme
southeast end of the Six Rivers National Forest. Aerial survey also observed scattered,
light mortality of large ponderosa pine over several thousand acres in a Late Successional
Reserve to the east of Anthony Peak on the Mendocino National Forest.
- M261D - Southern Cascades.
- Scattered mortality of ponderosa pine continued to occur on the Goosenest Ranger
District east of Mt. Hebron, on McCloud Flats and eastward to about Pondosa (Siskiyou
County), in the Lake Britton-Burney area (Shasta County), and along Highway 44 southeast
of Poison Lake (Lassen County).
- M261E - Sierra Nevada.
- Ponderosa pine mortality increased in some areas in the northern portion of the section.
Both western pine beetle and mountain pine beetle often were found attacking the same
tree. Areas of activity include several areas on the Sierraville District, Tahoe National
Forest, and in the area around Boca and Stampede Reservoirs (Nevada County) on the Truckee
District. Typical mortality patterns have been small groups (5-10 trees) scattered
throughout the host type. In scattered, single, large DBH ponderosa pine, western pine
beetle alone is causing mortality particularly on the east side of the Lassen, Plumas and
Tahoe National Forests. This and mortality from other bark beetles is included in Table 1.
- Mortality associated with western pine beetle and the mountain pine beetle remained at
generally low levels in the southern half of the section, consisting of scattered, small
groups of ponderosa pine and scattered individual sugar pine, respectively.
- M261G - Modoc Plateau.
- Ponderosa pine mortality associated with western pine beetle and mountain pine beetle
increased in 1995 on the Big Valley Ranger District, Modoc National Forest. Mortality was
most noticeable in the Dutch Flat and Knox Mountain areas. On the adjacent Doublehead
District, increasing levels of ponderosa pine mortality associated with western pine
beetle were noted on Timber Mountain.
- M262B - Southern California Mountains and Valleys
- Western pine beetle was the primary bark beetle involved in Coulter pine mortality in
southern California. Low levels (1 to 5%) of mortality were reported on 180 acres of the
Cleveland National Forest and on 85 acres of the Pala Reservation, San Diego County.
MOUNTAIN PINE BEETLE, Dendroctonus ponderosae.
- M261A - Klamath Mountains
- Sugar pine mortality caused by drought and mountain pine beetle has continued across
northern California. Scattered sugar pines of all size classes were killed on the Six
Rivers and the western part of the Klamath National Forests.
- Mountain pine beetle caused scattered mortality of sugar pine in Greenhorn Park,
Siskiyou County. It also contributed to ponderosa pine mortality either alone or in
conjunction with the western pine beetle. The red turpentine beetle was a common associate
in both tree species.
- M261D - Southern Cascades.
- Scattered old-growth sugar pines faded on isolated cinder cones south of Medicine Lake.
At least a dozen large sugar pines were killed by a combination of lightning strike,
drought and mountain pine beetle on top of a cinder cone adjacent to the Pole Springs Road
on the Lassen National Forest.
- Mountain pine beetle and Ips emarginatus were the causal agents of ponderosa pine
mortality near Old Station, Hat Creek Ranger District, Lassen National Forest. Mortality
was detected mainly in large, overstory pines on rocky outcrops or lava fields. Other
areas of increased mortality in ponderosa pine on the Lassen National Forest include Crazy
Harry Gulch, Bogard Buttes and in and around Blacks Mountain Experimental Forest. Attacks
by mountain pine beetle were primarily concentrated in the smaller size trees while
western pine beetle was often associated with larger dbh trees.
- Submersion and mountain pine beetle were responsible for lodgepole pine mortality along
Highway 44 near Hog Flat and McCoy Flat Reservoirs on the Eagle Lake District, Lassen
National Forest. Individual trees and groups of lodgepole pine were killed by the mountain
pine beetle between Tamarack Trailhead and Lake Eiler, Lassen National Forest.
- M261E - Sierra Nevada.
- Several stands throughout the northern portion of the Sierra Nevada section are
experiencing ponderosa pine mortality associated with mountain pine beetle. Areas of
activity include several areas on the Sierraville District, Tahoe National Forest, and in
the area around Boca and Stampede Reservoirs (Nevada County) on the Truckee Ranger
District. Typical mortality patterns have been small groups (5-10 trees) scattered
throughout the host type.
- Mortality of lodgepole pine also occurs on the Sierraville and Truckee Districts. Areas
experiencing high levels are Lemon Canyon (Lemon Canyon Road), Davies Creek, Rice Canyon
(89-55 Road west of Highway 89) in Sierra County, Sagehen Basin, Alder Creek, Donner Camp
(Nevada County) and the Silver Creek drainage along the Truckee River south of Truckee
(Placer County) have increased levels of lodgepole pine mortality in all size classes.
Large groups of lodgepole pine died this year in the area immediately north of Squaw
Valley off of Highway 89. Lodgepole pine trees covering about 100+ acres are dead in
Donner Memorial State Park on the southeast shore of Donner Lake (Nevada and Placer
Counties). This was the largest contiguous kill of lodgepole pine noted this year. Pockets
of lodgepole pine mortality continued to occur in a variety of areas around Lake Tahoe,
including Slaughterhouse Canyon, Meeks Creek and wetland areas on the south shore, and in
the Twin Lakes Campground and several other areas on the Mammoth Ranger District, Inyo
National Forest.
- In the central portion of the section, lodgepole mortality continued around Sample
Meadow on the Pineridge District, Sierra National Forest. Some mortality from mountain
pine beetle was evident in lodgepole pine defoliated by the lodgepole needleminer in the
Stanislaus National Forest and Yosemite National Park.
- M261G - Modoc Plateau.
- Ponderosa pine mortality associated with western pine beetle and mountain pine beetle
increased in 1995 on the Big Valley District, Modoc National Forest. Mortality was most
noticeable in the Dutch Flat and Knox Mountain areas.
- M262B - Southern California Mountains and Valleys
- Populations of mountain pine beetle were low in the San Bernardino and San Jacinto
Mountains, although some mortality attributed to this insect was reported from private
land in Idyllwild.
FIR ENGRAVER, Scolytus ventralis.
- M261A - Klamath Mountain
- Very high white fir mortality occurred in the Taylor Creek Late Successional Reserve
(Klamath National Forest) over the past couple of years. The south end of the mortality
area extends into the Trinity Alps Wilderness.
- M261B - Northern California Coast Ranges.
- There was scattered white fir mortality on the Mendocino National Forest, particularly
just below the eastern crest along Black Butte, Mendocino Pass, and Anthony Peak. More
well-defined were areas of low white fir mortality near Shell Mountain in the Middle
Eel-Yolla Bolla Wilderness.
- M261D - Southern Cascades.
- White fir mortality continues on the east side of the Sierra Nevada throughout the
Southern Cascades section. Fir engraver, over stocking, off-site species, and a decrease
in annual precipitation 8 of the past 10 years have contributed to extremely high levels
of fir mortality. For several years very high white fir mortality has continued in the
Ball Mountain Late Successional Reserve on the Goosenest District, Klamath National
Forest. Mortality has tapered off in other areas which previously had high white fir
mortality. Specific areas that now have a low, scattered level include Mt. Shasta and
Hambone Butte.
- On the Lassen National Forest, white fir mortality continues on Pegleg and Harvey
Mountains, Eagle Lake Ranger District. Red fir mortality has increased substantially on
the Eagle Lake District as well. Particular areas include Gillman Basin, Fox Mountain, and
Hamilton Mountain (M261E). Numerous white fir of all sizes were killed by fir engravers
between the Tamarack Trailhead and Lake Eiler, Hat Creek District, Lassen National Forest.
- Southward on the Plumas National Forest, Clarks Peak, the area around Lake Davis, and
areas near the Dixie Mountain State Game Refuge (Milford Ranger District) have high white
fir mortality. On the adjacent Greenville District, Franks Valley and Wheeler Peak
watersheds have levels of similar mortality.
- M261E - Sierra Nevada.
- On the Sierraville District, Tahoe National Forest, Treasure Mountain, the area along
Highway 89 south of Sierraville to Truckee, the east side of the Bald Mountain Range, Tros
Canyon, Henness Pass, and the Bonta Creek Drainage (Sierra County) have high levels of
mortality related to the fir engraver. The mortality is primarily in white fir, however,
fir engraver and wood borers have also caused some red fir mortality at the higher
elevations. On the Truckee District substantial increases in fir mortality were noted in
the Sagehen Basin and Worn Mill Canyon (east of Stampede Reservoir, south of the 1994
Crystal fire).
- In and around the Angora Highlands Subdivision at South Lake Tahoe, white fir mortality
has declined to near or slightly above pre-drought levels. The majority of residual live
trees exhibit evidence of attack, including pitch streaming (not a consistent indicator),
patches of dead cambium scattered along the main stem, dead branches scattered through the
live crown, thin and/or chlorotic crowns, and dead, thin and/or chlorotic tops. Low vigor
among these fir places them at an increased risk for mortality. Moderate levels of white
fir mortality, due in part to fir engraver activity, were evident in several other
locations, including the north shore of Lake Tahoe. Above normal red fir mortality
continued in the vicinity of Genoa and Bliss Peaks on the east side of Lake Tahoe. The fir
engraver and roundheaded fir borer were associated with this mortality.
- Dead tops and mortality became noticeable in late summer in mid-elevation mixed conifer
and fir stands in Tuolumne, Calaveras and Amador Counties. The roundheaded fir borer,
Tetropium abietis, was often found infesting the lower bole of fir killed by the fir
engraver.
- M261G - Modoc Plateau.
- Fir engraver beetle, high stand densities and low annual precipitation for several years
have resulted in high levels of fir mortality in Modoc County. Mortality in white fir
continued in 1995 in several areas such as Roney Flat, Niles Canyon, Hunters Ridge,
Manzanita Ridge and several canyons near Deer Spring Ridge on the Big Valley Ranger
District. Extreme mortality (in excess of 80% of the stands) has occurred in some of these
areas over the past three years. Numerous groups of fading white fir were evident along
the west slope of the Warner Mountains north of Cedar Pass. In 1995 the number of acres
affected in the Warner Mountains increased 15% above the acres detected in 1994.
- On the other hand, white fir mortality on private lands west of Goose Lake and in the
Cal Pines subdivision, Modoc County, was estimated to be less than 5% this year.
Considering the abundant precipitation during the winter and spring of 1995, the number of
fading trees in the spring of 1996 should be at or near pre-drought levels in these areas.
In southwestern Modoc County, few fading white firs were evident from Highway 299, a sharp
contrast to the previous two years.
- M262B - Southern California Mountains and Valleys
- The fir engraver was a factor in the low levels of white fir mortality on the San
Bernardino National Forest and on 200 acres of Cuyamaca State park in San Diego County.
PINE ENGRAVER BEETLES, Ips spp.
- 261A - Central California Coast
- Ips mexicanus and I. plastographus infested Monterey pine blowdown at New
Brighton State Beach following a January storm. The infested material was bucked and
hauled away prior to emergence.
- 263A Northern California Coast
- Bishop pine log decks near Point Arena were mass attacked in late winter by two species.
The logs were infested at a 3:1 ratio by I. plastogrphus to I. mexicanus.
- M261A - Klamath Mountains
- Pine engravers killed knobcone pines near Whiskeytown Lake, Shasta County. These trees
were near winter storm breakage piled by crews for burning at some later date. A few
top-killed ponderosa pines were noticed around Scott Valley, Siskiyou County.
- M261D - Southern Cascades.
- Ips emarginatus and mountain pine beetle were the causal agents of ponderosa pine
mortality near Old Station, eastern Shasta County. Mortality was detected most frequently
in large, overstory pines on rocky outcrops or lava fields.
- M261E - Sierra Nevada.
- During late March and early April, wet, heavy snow storms hit the Foresthill area,
Placer County, causing extensive breakage of branches and whole trees. Tree tops snapped
off at about 10-15 feet above ground in an elevational band between 3,500 - 4,200 feet.
Damage occurred over some 2,000 acres primarily in the Volcano Plantations, Tahoe National
Forest. The material was infested with Ips paraconfusus by late May. The Foresthill Ranger
District responded with an aggressive program to buck up and chip material that was close
to roads. As of September, the remaining snow breakage material is still being utilized by
pine engravers. Additional projects will be conducted next year to remove additional down
material prior to beetle flight.
- Ips emarginatus and Jeffrey pine beetle were found in several trees east of Boca
Reservoir (Nevada County), and along the 08 Road in the Pole Creek drainage, Truckee
District, Tahoe National Forest.
- M262B - Southern California Mountains and Valleys
- Engraver beetles were involved in low levels (1 to 5%) of Jeffrey pine mortality on 770
acres on Big Pine Mountain on the Los Padres National Forest. Both roundheaded and
flatheaded borers were also involved, but the Jeffrey pine beetle was not found, nor has
it been reported west of the San Bernardino Mountains. Engravers were probably also
involved in scattered patches of low levels of Jeffrey and ponderosa pine mortality on the
Angeles National Forest. Engravers also played a role in light mortality of Jeffrey x
Coulter pine hybrids on Thomas Mountain in the San Bernardino National Forest.
- Pinyon pines dying from black stain root disease in the eastern portion of the San
Bernardino Mountains were also infested with pine engravers, which are usually the
immediate cause of death, although trees have been observed to die of the disease alone.
Pinyon black stain in that area is widespread and longstanding, and mortality can be
expected to continue indefinitely. Private property owners within the infested area have
expressed concern about this mortality.
DOUGLAS-FIR BEETLE, Dendroctonus pseudotsugae.
- 263A - Northern California Coast
- Douglas-fir beetle infested a small number of Douglas-firs felled by storms near Piercy,
Mendocino County. It was associated with the flatheaded fir borer in attakcs on
Douglas-firs northwest of Willits and near Gualala, Mendocino County.
- M261A - Klamath Mountains
- A few very scattered trees were attacked by Douglas-fir beetle along the upper
Sacramento River between Lake Siskiyou and Gumboot Lake. There were also a few
Douglas-firs attacked along the lower part of Fawn Creek, which is a tributary to the
upper Sacramento. A few poorly growing Douglas-firs were killed by Douglas-fir beetle near
Gunsight Peak west of Yreka. In addition to stress from extended drought, most of these
trees had severe dwarf mistletoe infections.
- During 1994 two pheromone blends were compared in their ability to cause Douglas-fir
beetle to fatally attack old dwarf mistletoe-infected Douglas-firs in an area of Siskiyou
County located between Sawyers Bar and Cecilville. Attacks induced by one of the
formulations resulted in considerable frass being produced by the late summer of 1994. All
of these trees appeared very green and healthy when examined during the summer of 1995.
The attacks were apparently not successful.
JEFFREY PINE BEETLE, Dendroctonus jeffreyi.
- M261D - Southern Cascades.
- Mortality caused by Jeffrey pine beetle attacks on drought-stressed trees has been
increasing for several years throughout the host range in northeastern California.
Currently fading trees and green-attacked trees were common in the northern end of Lassen
Volcanic National Park and adjacent parts of the Lassen National Forest. On the Forest,
specific locations of current Jeffrey pine mortality include: Summit Lake, Duck Lake, near
the Highway 89 and Butte Lake entrances to the Park, along Lost Creek and around Lost
Spring, and along the Pole Springs Road. Mortality is occuring in both large overstory
trees, and also in groups of young pole-size trees. Mortality of old growth Jeffrey pine
continued in the area between the Tamarack Trailhead and Lake Eiler, Lassen National
Forest.
- In Lassen National Park, mortality was noted around Manzanita Lake, Table Mountain,
Butte lake and throughout the northern portion of Lassen National Park. Of particular note
was an 800 tree group-kill near Lost Creek along Highway 89 just north of the summit.
- M261E - Sierra Nevada.
- The Milford Ranger District, Plumas National Forest, recorded increases in Jeffrey pine
beetle-related mortality in the Squaw Creek drainage, the upper Indian Creek drainage,
south of Antelope Lake, and on Stoney Ridge. Group kills involving small diameter trees
and single tree mortality in large diameter trees was most common.
- Extensive small group kills associated with Jeffrey pine beetle were noted along
Smithneck Creek, Rice Canyon, Cold Creek, Onion Valley and Antelope Valley on the
Sierraville District, Tahoe National Forest. On the Truckee Ranger District extensive
Jeffrey pine mortality is evident throughout the Truckee River drainage along Highway 89
south of Truckee, particularly along the 08 Road in the Silver Creek, Pole Creek and Deep
Creek drainages. Mortality is also evident along Highway 267 south east of Martis
Reservoir (Placer County). Several small pockets of dead trees are also visible along
Interstate 80 between Truckee and Donner Lake.
- Mortality associated with the Jeffrey pine beetle continued at above background levels
in the vicinity of Lake Tahoe, adjacent areas on the Toiyabe National Forest in Nevada,
and on the Inyo National Forest. Large mortality centers occurred on the east shore of
Lake Tahoe in or near Secret Harbor, Slaughterhouse Canyon, Spooner Summit, Glenbrook and
Round Hill. Pockets of Jeffrey pine mortality were evident on the south shore between
Myers and Tahoe Valley. Jeffrey pine mortality also continued on the Mammoth Ranger
District in Mono County in the vicinity of the Inyo Craters, Deadman Creek, Old Shady Rest
Campground, and scattered between the Mammoth Scenic Loop and the Obsidian Flat/Deadman
Campground roads.
- M262B - Southern California Mountains and Valleys
- Jeffrey pine beetle populations were low in the San Bernardino Mountains when compared
to recent years. Jeffrey pine mortality was low, and some of the mortality which did occur
within the range of this beetle was caused by other insects.
RED TURPENTINE BEETLE, Dendroctonus valens.
- M261B - Northern California Coast Ranges
- Reports of red turpentine beetles were on the increase in ponderosa pine around Cobb,
Lake County. A few large trees near Hearst, Mendocino County, had numerous attacks, some
as high as 12-to-15 feet above ground line.
- M261E - Sierra Nevada.
- Red turpentine beetles were found attacking residual lodgepole pines following a timber
sale near the north shore of Prosser Creek Reservoir, and in the Donner Camp area, Truckee
District, Tahoe National Forest. Attacks did not result in tree mortality. Red turpentine
beetles were also noted in the snow damage trees on the Foresthill District, Tahoe
National Forest (see pine engravers). Very low levels of red turpentine beetle were found
on pine under attack by the Jeffrey pine beetle in the Lake Tahoe Basin and on the Inyo
National Forest.
- M262B - Southern California Mountains and Valleys
- The red turpentine beetle was common in its hosts in the mountains of southern
California, but no tree mortality was attributed to this insect.
FLATHEADED FIR BORER, Melanophila drummondi.
- 261A - Central California Coast
- Flatheaded fir borer combined with Armillaria root disease to kill mature
Douglas-fir near Scotts Valley, Santa Clara County.
- 263A - Northern California Coast
- Flatheaded fir borer combined with Douglas-fir beetle to kill Douglas-fir northwest of
Willits and near Gualala, Mendocino County. In Humboldt County, the borer combined with Armillaria
root disease to kill Douglas-fir at the west end of the Salmon Creek drainage.
- M261A - Klamath Mountains
- The north-facing slope along the Klamath River had very visible fading of Douglas-fir.
The extended drought conditions have allowed the flatheaded fir borer to complete
development in a large number of trees on these low quality sites. Douglas-fir mortality
also was scattered throughout Greenhorn Park, a large tract of wildlands near the city of
Yreka, Siskiyou County. Attacks of the flatheaded fir borer were associated with dead and
dying trees as well as live trees with pitch streaming and weakened crowns.
- M261B - Northern California Coast Ranges
- Groups of pole-sized and larger Douglas-fir were killed in northeastern Mendocino County
where Douglas-fir blended with oak woodland.
- M261G - Modoc Plateau.
- The flatheaded fir borer was a common associate of the fir engraver on the Big Valley
District, Modoc National Forest. Infested areas include Roney Flat, Niles Canyon, Hunters
Ridge, Manzanita Ridge and several canyons near Deer Spring Ridge. Borers were also
associated with the fir mortality in the Warner Mountains, Modoc County.
ROUNDHEADED FIR BORER, Tetropium abietis.
- M261A - Klamath Mountains
- There is an area of red fir mortality near Trinity Mountain above Horse Linto and Tish
Tang Creeks in the Trinity Alps Wilderness Area. Dwarf mistletoe, cytospora canker,
drought, fir engraver and roundheaded fir borer have all played some role in the
mortality.
- M261D - Southern Cascades.
- Roundheaded fir borer and fir engraver beetle have caused an increase in red fir
mortality on the Eagle Lake District, Lassen National Forest. Areas include Gillman Basin,
Fox Mountain, and Hamilton Mountain (261E).
- M261E - Sierra Nevada.
- In the southern portion of the section, the roundheaded fir borer was often found
infesting the lower bole of fir killed by the fir engraver.
CALIFORNIA FLATHEADED BORER, Melanophila californica
- M262B - Southern California Mountains and Valleys
- The California Department of Forestry and Fire Protection reported group kills of
Jeffrey pine by the flatheaded borer on private land in Garner Valley, San Jacinto
Mountains. Flatheaded borers also were involved in tree mortlaity on private land in the
communities of Idyllwild, Riverside County, and Wrightwood, San Bernardino County.
DOUGLAS-FIR ENGRAVER, Scolytus unispinosus.
- 263A - Northern California Coast
- This engraver killed a few Armillaria infected Douglas-firs northwest of Willits,
Mendocino County, and pole-sized Douglas-fir west of Salmon Creek in Humboldt County.
- M261A - Klamath Mountains
- The Douglas-fir engraver was present in the tops and limbs of most of the trees attacked
by the flatheaded fir borer or the Douglas-fir beetle.
CEDAR BARK BEETLES, Phloeosinus spp.
- M261B - Northern California Coast Ranges
- Mortality and branch flagging occurred in several ornamental Leyland cypress in hot, dry
areas southeast of Ukiah, Mendocino County. Some of the trees were also infected with
Seiridium cardinale, a canker fungus spread by the beetles.
- M261A - Klamath Mountains
- The forest adjacent to the northern end of Trinity Lake and many other areas in northern
California had extensive mortality of understory incense-cedar. These trees were infested
with cedar bark beetles during the extremely dry summer of 1994. In addition to
drought-stress, these trees had often been suppressed for many years and many also had
been severely wounded during previous logging. A small percentage of the cedar mortality
was comprised of thrifty appearing trees.
- M261G - Modoc Plateau.
- Cedar bark beetles, scales and wood borers caused decline and death of several cedars on
the Big Valley Ranger District, Modoc National Forest. Mortality and top kill were quite
evident in the Niles Flat and Roney Flat areas.
PINE REPRODUCTION WEEVIL, Cylindrocopturus eatoni
- M261D - Southern Cascades
- This weevil caused scattered mortality of ponderosa pine in a plantation near Whitmore,
Shasta County. Infestations were mostly limited to the upper and outer portions of the
crowns. A secondary invader that colonized the mainstems was a bark beetle in the genus Carphoborus.
Brush competition appears to have contributed to the outbreak.
- M261E - Sierra Nevada.
- Three-year old ponderosa pine seedlings were killed for the second year in a plantation
on the Groveland District, Stanislaus National Forest. Mortality and damage were found
over five to six acres and associated with heavy brush competition.
MODOC BUDWORM, Choristoneura retiniana.
- M261G - Modoc Plateau.
- Feeding could be detected on individual white fir trees near Benton Meadow in the Warner
Mountains this year, but there is so much faded foliage from white fir mortality caused by
the fir engraver that it is difficult to gauge the severity of the defoliation.
A CALIFORNIA SPRUCE BUDWORM, Choristoneura carnana californica.
- M261A - Klamath Mountains
- Feeding was noted on four Douglas-fir seedlings in a plantation adjacent to Highland
Ridge and Five Mile Creek on the Weaverville District, Shasta-Trinity National Forest.
DOUGLAS-FIR TUSSOCK MOTH, Orgyia pseudotsugata.
- M261D - Southern Cascades and M261G - Modoc Plateau
- Male moth catches from "early warning" monitoring traps throughout
northeastern California indicate a general increase in the number of male moths caught
when compared to 1994 counts. Egg mass surveys are planned for the winter and larval
surveys will be conducted in the spring of 1996. Plots in these general areas will receive
particular attention: Eagle Lake Ranger District, Lassen National Forest; Warner Mountain
Ranger District, Modoc National Forest and the Goose Lake area, Modoc County.
- M261E - Sierra Nevada
- Male moth catches from monitoring traps indicate a general increase in the number of
male moths at plots in Schneider Creek, Feather River Ranger District, Plumas National
Forest; and one plot on each of the Downieville and Nevada City Ranger Districts, Tahoe
National Forest. Egg mass and larval surveys are planned in conjuction with the surveys
that will occur in the Southern Cascades and Modoc Plateau Regions.
- For the first time in several years, trap catches showed consistent, substantial
increases in monitoring plots located on the Eldorado and Stanislaus National Forests.
Numbers from two of 10 plots increased on the Mariposa Ranger District, Sierra National
Forest, while numbers from traps on the Mammoth District, Inyo National Forest, remained
at very low levels. Similar increases preceeded the last outbreak in California (1987-89)
by two to three years.
GYPSY MOTH, Lymantria dispar
- Statewide
- Nineteen moths were trapped in eight counties - Los Angeles, Napa, Nevada, San
Francisco, Santa Barbara, Santa Clara, Santa Cruz and Sonoma. Numbers trapped were about
the same as in 1994 with the exception of an area in Santa Cruz County near Felton (6
moths and one property with egg masses), and an area in Nevada County near Grass Valley (5
moths). The finds in Nevada County were within a high density delimitation zone
established in 1994.
TENT CATERPILLAR, Malacosoma sp.
- M261D - Southern Cascades.
- Tent caterpillar defoliation of bitterbrush was very apparent throughout the southern
portion of the Southern Casacades section. Individual branches were completely consumed
and tent formation exceeded 2-3 tents per bush in some areas. Bitterbrush mortality is not
expected as a result of the defoliation this year, however these areas will be monitored
next year to determine if the tent caterpillar populations are causing damage and/or
mortality.
- M261E - Sierra Nevada.
- The western tent caterpillar, Malacosoma californicum, was prevalent on bitterbrush in
areas from northern Lake Tahoe to north of Truckee, including Hobart Mills (Placer County)
and areas west of Burton Creek State Park in the Lake Tahoe Basin. Populations appear to
be in the second or third year of an outbreak.
WHITE FIR SAWFLY, Neodiprion nr. deleoni and abietis
- M261D - Southern Cascades.
- Outbreak populations of the white fir sawfly between Eagle Lake and Lake Almanor, Lassen
and Plumas Counties, and on the north side of Cornaz Peak, Shasta County, have collapsed
to endemic levels. A reduced compliment of foliage exists on trees that were defoliated
during the past couple of years.
- M261E - Sierra Nevada.
- Sawfly activity has been detected over the past three years along the south fork of Long
Valley Creek and into the Willow Creek drainage on the Beckwourth District, Plumas
National Forest. No mortality was attributable to this feeding.
- Moderate amounts of defoliation were attributed to feeding by white fir sawfly on lower
white fir branches in several locations on the Placerville District, Eldorado National
Forest.
LODGEPOLE PINE NEEDLEMINER, Coleotechnites milleri.
- M261E - Sierra Nevada.
- The lodgepole pine needleminer caused moderate to high defoliation in areas of the
Stanislaus National Forest and Yosemite National Park in Tuolumne and Mariposa Counties.
Areas with evident, recent defoliation include Horse Meadow (Emigrant Basin Primative
Area), Falls Creek near Kendrick Peak, Lyell Canyon near Ireland Creek, Cathedral
Fork/Echo Creek and May Lake. Total area involved is estimated to be about 8,000 to 10,000
acres. Some mortality caused by mountain pine beetle was evident in lodgepole needleminer
defoliated areas.
GOUTY PITCH MIDGE, Cecidomyia piniinopsis.
- M261D - Southern Cascades
- A 30-year-old, mixed plantation of ponderosa and Jeffrey pines in the Manzanita Chute
northwest of Lassen Volcanic National Park contained many trees with visible infestations.
Fairly conspicuous flagging of branch tips occurred in an older pine plantation near the
Cypress Camp Trailhead to the Thousand Lakes Wilderness, Lassen National Forest.
- M261E - Sierra Nevada.
- Moderate levels of branch flagging caused by the gouty pitch midge occurred in several
areas of the Wrights Creek plantation on the Mi-wok District, Stanislaus National Forest.
PINE NEEDLE SHEATHMINER, Zelleria haimbachi
- M261D - Southern Cascades
- An outbreak of the pine needle sheathminer persists on ponderosa pine east of Pondosa
(old Pondosa burn), Siskiyou County. Defoliation last year resulted in the nearly complete
loss of 1994 needles on the most heavily damaged trees. Populations in 1994 were estimated
at 9.4 larvae per shoot. Although 1995 populations were significantly less at 1.8 larvae
per shoot, they were still high enough to cause noticeable defoliation. On trees that had
lost most of their 1994 foliage, 1993 needles served as the primary oviposition site for
the current generation.
TIMEMA, Timema spp.
- 263A - Northern California Coast
- A new species of Timema has defoliated Douglas-fir of all sizes on Rainbow Ridge in
Humboldt County and Pine Ridge in Mendocino County. (The name T. douglasi has been
proposed, but is unpublished.) The dense stand on Rainbow Ridge had nearly 15% mortality
over the last two years. The dead trees were mostly pole-sized Douglas-fir with low live
crown ratios when defoliation began. A few of the defoliated trees were attacked by Hylastes
nigrinus and had Armillaria root disease. A few other Timema sightings
include areas near Lake Sonoma (Sonoma County), northwest of Ukiah, and Leggett, both in
Mendocino County.
SEQUOIA PITCH MOTH, Syanthedon sequoiae
- M261B - Northern California Coast Ranges
- About 125 Monterey pine near Lakeport and Blue Lakes (Lake County) were reported to have
extensive attacks.
CALIFORNIA OAKWORM, Phryganidia californica
- 263A - Northern California Coast
- Tanoaks were defoliated northwest of Cloverdale and east of Yorkville in Mendocino
County. Most of the defoliated tanoaks are within areas logged one to two years ago.
FRUITTREE LEAFROLLER, Archips argyrospilus+
- 262B - Southern California Mountains and Valleys
- Light defoliation of black oak was observed in the Mendenhall Valley within the
boundaries of the Cleveland National Forest.
AFRICANIZED HONEY BEE, Apis mellifera scutellata
- 322B and C - Sonoran Mojave and Sonoran Colorado deserts
- Thirteen naturally moving swarms and one colony were detected in California as of
December 1, 1995. Additional swarms were found and eradicated on ships in ports. All of
Imperial County, a large portion of southeastern Riverside County, and a lesser portion of
northeast San Diego County are now considered colonized. Following the 12th find on the
north shore of the Salton Sea, the colonized area was considered to include 8253 square
miles. No swarms have been found in forested areas of the state thus far.
- To date there have been no major human stinging incidents in California. In 1995 there
were two human fatalities in Arizona attributed to stinging by the Africanized honey bee
(AHB), in addition to two previous fatalities in Texas - one attributed to AHB and one to
European honey bees with Africanized introgression.
Table 1. Mortality from Bark Beetles within the National
Forest System, California, 1995*
|
Acres of Mortality** |
Volume (MMBF) |
Locale |
Pine |
Fir |
Total |
Pine |
Fir |
Total *** |
Northern California |
75653 |
121089 |
196745 |
50 |
183.3 |
335.3 |
Cascade North Sierra |
163019 |
163376 |
316395 |
53 |
105 |
269 |
Central/South Sierra |
57829 |
35024 |
92849 |
27.5 |
30.9 |
149.5 |
Southern California |
1558 |
1405 |
2963 |
0.7 |
0.1 |
2 |
Total |
288059 |
320894 |
608952 |
131.2 |
319.3 |
755.8 |
Table 2, Insects of Lesser Importance in California
1995
Insects |
Where Examined or Reported |
Scientific & Common Names |
Host |
County |
Remarks |
Asterolecanium minus Oak pit scale |
LO |
Santa Cruz |
Several coast live oaks near Scotts Valley had branch flagging from a
combination of pit scale and twig decline fungi. |
Contarinia spp. Douglas-fir needle midges |
DF |
Sonoma, Lake |
Three species were associated with needle damage in Christmas tree
plantations near Sonoma and Kelseyville. |
Euthoracaphis umbellulariae California laurel aphid |
CL |
Santa Cruz |
Excessive sooty mold was the result of an infestation near Scotts
Valley. |
Melissopus latiferreanus Filbertworm |
LO |
Mendocino |
Infested acorns had associated drippy nut bacterial ooze that caused
unsightly sidewalk spotting on the Medocino College campus. |
unknown Aphid |
AE |
Mendocino |
Extensive honeydew was a problem on a scenic drive into a winery near
Hopland. |
unknown Cicada |
DF |
Shasta, Trinity, Siskiyou |
Cast nymphal skins very abundant, some minor oviposition damage to
twigs. |
unknown Thrips |
DF |
Santa Clara |
Thrips were collected from "curly needles" in a Christmas
tree plantation. |
unknown Weevil |
BP |
Mendocino |
An unidentified weevil caused branch and leader dieback in planted
trees near Navarro. |
unknown Sesiidae
A pitch moth |
KxM |
Riverside |
An unidentified pitch moth was reared from larvae collected in a
plantation in the San Jacinto Mountains. |
Host Abbreviations
AE - American elm, BP - Bishop pine, CL - California laurel, DF -
Douglas-fir, IC - Incense-cedar, LO - Live oak
____________________________________
Back to Contents
Status and Control of Disease
A Report to the California Forest Pest Council from the Disease Committee
John Pronos, Chair
John Kliejunas, Secretary
ABIOTIC DISEASES
DROUGHT-RELATED EFFECTS
- M261D - Southern Cascades
- Incense-cedar with thin crowns were common in the vicinities of Whitmore (Shasta County)
and Weed (Siskiyou County). Crowns have thinned from the top down and outside in,
indicating extended drought stress. Wood borers were associated with scattered mortality
of these trees.
- M261E - Sierra Nevada
- Declining and recently dead Douglas-fir at a progeny test site near Feather Falls (Butte
County) exhibited symptoms of drought stress, i.e. crown thinning from the top down and
outside in. Genetic predisposition and localized soil conditions may also have been
contributing factors.
WINTER FLECK
- M261A - Klamath Mountains
- In the Spring, ponderosa pine reproduction on the west side of the Fountain Fire burn
(Shasta County) exhibited discreet tan flecking on the upper surfaces of the needles. The
cosmetic damage resulted from exposure to low temperatures and snow.
WATER DAMAGE TO PINE FOLIAGE
- M261D - Southern Cascades
- Ponderosa and Jeffrey pine reproduction on Coyote Flat, west of Lake Almanor (Plumas
County), suffered extensive foliage damage this spring. Sites where damage was observed
were relatively open, low lying areas. All needles on small trees to approximately 3 feet
high were completely brown or brown mottled. Taller trees had a distinct demarcation
between brown lower needles and green needles above. The demarcation existed at the same
level across a given site, indicating a distinct layer of damage, such as might be caused
by standing water. Stems of damaged trees were green and firmly rooted in the ground. Some
smaller trees had dead buds, but the majority did not. While ponderosa and Jeffrey pines
were uniformly affected, intermixed white fir and lodgepole pine showed no damage.
RED BELT, winter needle desiccation
- M261D - Southern Cascades
- Several miles of red belt damage to ponderosa pine occurred along the eastern and
northeastern edge of Goose Valley near Burney (Shasta County). Recent tree mortality due
to the western pine beetle was scattered among the damaged trees. The redbelt, combined
with low site conditions, has the potential to aggravate existing bark beetle activity.
OZONE
- M261E - Sierra Nevada
- In August and September, 1995, 26 air pollution monitoring plots were visited on the
Sierra National Forest (Mariposa, Madera, and Fresno Counties). When compared to injury
ratings recorded in 1993, the general trend was either no change or higher injury scores.
Forty-six percent of the plots showed increased injury, 39% no change, and 15% showed less
injury.
- Plots with trees experiencing the largest increases in injury were mainly at elevations
of 4000 and 5000 feet, while the few plots with slightly improved scores were at 6000 feet
or higher. It is anticipated that future ozone injury ratings may increase if
precipitation continues at normal or above levels.
STORM DAMAGE
- M261D - Southern Cascades
- High winds and heavy rains in December of 1994 caused windthrow of several hundred acres
of knobcone pine on the west side of Siskiyou Lake (Siskiyou County). Most of the material
was salvaged during the summer. Heavy snows in 1994-95 resulted in a major avalanche on
the south side of Mt. Shasta (Siskiyou County). Over a million board feet of red fir were
felled by the avalanche which covered several hundred acres. Some of the material will be
salvaged.
CANKER DISEASES
PINE PITCH CANKER, Fusarium subglutinans f. sp. pini
- 261A - Central California Coast
- Late in 1994, pine pitch canker was confirmed on Monterey pine in the Cambria area, San
Luis Obispo County. The disease is now present in all three of California's native
Monterey pine stands. It is well established at San Simeon State Park, several miles north
of the town of Cambria, and is present in Cambria proper. Two infected trees along Highway
1 in Cambria were removed early in 1995. All symptoms of the disease were present in the
stand at San Simeon State Park, including tree mortality. The disease is presumed to have
been present in the area at least 2 to 3 years prior to its discovery.
- The Pine Pitch Canker Task Force, a coalition of governmental, private, and non-profit
groups formed by the California Forest Pest Council, held its first meeting in December
1994. A major effort of the task force has been the dissemination of information on pitch
canker, with the intent of lessening the impact and spread of the disease. Management and
research priorities have been identified; future efforts will concentrate on funding and
coordinating proposed activities. Reports from the Task Force are available.
- 263A - Northern California Coast
- Symptoms of pine pitch canker in Monterey pine in northern Santa Rosa have not
significantly increased beyond those noted a few years ago. A resampling of the infected
Monterey pine in Ukiah (Mendocino County) was negative for the fungus.
MADRONE CANKER, Fusicoccum aesculi
- 263A - Northern California Coast
- Madrone canker killed clumps of Pacific madrone northwest of Willits (Mendocino County).
PHOMOPSIS CANKER, Phomopsis lokoyae
- 263A - Northern California Coast
- Phomopsis lokoyae caused branch and top kill of Douglas-fir saplings near Philo
(Mendocino County) and along Salmon Creek (Humboldt County).
- M261B - Northern California Coast Ranges
- A few planted Douglas-fir saplings and pole-sized trees northeast of Lake Mendocino
(Mendocino County) had branch and top kill caused by to Phomopsis lokoyae.
SERIDIUM CANKER, Seridium cardinale
- 261A - Central California Coast
- Seridium cardinale caused branch flagging of redwood near Carmel (Monterey
County).
- M261B - Northern California Coast Ranges
- Several stems of Leyland cypress southeast of Ukiah (Mendocino County) were infected
with Seridium cardinale. The infected stems were also infested with cedar/cypress bark
beetles.
WILLOW DIEBACK, Unknown canker fungi
Several weeping willow trees in the Redwood Valley area had various levels of branch
mortality associated with elongated branch cankers. The pathogen was not identified.
FOLIAGE DISEASES
CYCLANEUSMA NEEDLECAST, Cyclaneusma minus
- 263A - Northern California Coast
- Cyclaneusma needlecast infected planted Monterey pine west of Boonville and south
of Mendocino (Mendocino County). At the Boonville site, Bishop pine were planted along
with Monterey pine, but Bishop pine was not infected.
SEPTORIA LEAF BLIGHT, Septoria quercicola
- M261A - Klamath Mountains
- Black oaks along many drainages were affected by Septoria leaf blight. Early
mortality of foliage and defoliation occurred along the Scott and Klamath Rivers (Siskiyou
County), and the Trinity River (Trinity and Humboldt Counties).
- 263A - Northern California Coast
- For the past two years, a few black oaks west of Ukiah (Mendocino County) have had
severe Septoria quercicola infections, resulting in crown dieback.
- M261B - Northern California Coast Ranges
- Black oaks were defoliated prematurely in July and August around Lake Pillsbury,
Mendocino National Forest (Lake County), because of heavy infection by Septoria
quercicola.
LEAF SPOTS ON CALIFORNIA LAUREL, Pseudomonas lauracearum, Colletotrichum
gloeosporioides, Monochaetia sp.
- 261A - Central California Coast
- Angular leaf spots caused by Pseudomonas lauracearum, Colletotrichum
gloeosporioides, and Monochaetia sp. caused bay trees to appear blighted in wet
areas near Scotts Valley (Santa Cruz County).
OAK ANTHRACNOSE
- M261 and M261F - Northern California Interior Coast Ranges and Sierra Nevada Foothills
- Anthracnose symptoms were present on blue and valley oaks in the upper Sacramento Valley
(Shasta County), although not nearly as prevalent or severe as in 1993. Premature
defoliation was rare, presumably due to the combination of mild symptoms and moderate
summer weather.
SYCAMORE ANTHRACNOSE
- M262B Southern California Mountains and Valleys
- Sycamore anthracnose caused heavy defoliation of western sycamore in the Upper Big
Tujunga Canyon, Arroyo-Seco Ranger District, Angeles National Forest (Los Angeles County).
Damage was noted in late May at 3500 foot elevation. Anthracnose was also very common
along the West Fork San Gabriel River on the Mt. Baldy Ranger District, Angeles National
Forest (Los Angeles County).
NURSERY DISEASES
FUSARIUM ROOT AND HYPOCOTYL ROT, Fusarium spp.
Growth of red fir container stock at Chico Genetic Resource Center (Butte County) was
suppressed by Fusarium hypocotyl rot. Shading improved the condition of the seedlings.
UNKNOWN
At Chico Genetic Resource Center (Butte County), container stock of a number of shrub
species exhibited dieback symptoms, including leaf spotting, marginal and tip necrosis,
and water soaking. Species affected included deerbrush, buckbrush, mountain mahogany, and
red alder. Both 1-0 and 2-0 stock were affected, but causal agent was not identified. It
is suspected that cultural practices, mainly acidification of irrigation water, may be
involved.
BACTERIAL CANKER, Pseudomonas syringae
The bacterial canker of Camptotheca acuminata re-occurred during the winter at
the Chico Genetic Resource Center (Butte County). Levels were not as severe as in 1994,
but several areas in the production orchard were affected by stem dieback.
CHARCOAL ROOT ROT, Macrophomina phaseolina
Macrophomina phaseolina killed approximately 5% of the 1-0 red fir crop at
Placerville Nursery (El Dorado County). Two years ago the nursery discontinued fumigating
with methyl bromide, which has allowed a build-up of pathogen microsclerotia in the soil.
The disease was limited to one field.
SOILBORNE DIEASES, Fusarium spp. and Phoma spp.
Two-year-old red fir, white fir and Douglas-fir at Humboldt Nursery (Humboldt County)
were killed by Fusarium and Phoma. Damage levels ranged from 1% to 10% in several nursery
beds.
WILLOW BLIGHT, Venturia saliciperda.
Willow cuttings at Humboldt Nursery (Humboldt County) died back due to willow blight.
The fungus caused dieback of lateral branches, the affected areas turned black, and leaves
shrivelled and dropped. The blight affected approximately 15% of the crop.
ROOT DISEASES
PORT-ORFORD-CEDAR ROOT DISEASE, Phytophthora lateralis
- 263A - Northern California Coast
- Port-Orford-cedar root disease was found in two ornamental plantings along Highway 101
near Lost Man Creek north of Orick (Humboldt County) and near High Prairie Creek near
Requa (Del Norte County). Each case involved only a single Port-Orford-cedar.
- M261A - Klamath Mountains
- Port-Orford-cedar root disease was identified in the headwaters of Potato Patch Creek on
the Smith River National Recreation Area (Del Norte County). This is part of the Klamath
River watershed and is the first identification of this disease in native stands of
Port-Orford-cedar in California beyond the Smith River watershed. Based on the size and
condition of the trees that have died, it is estimated that the pathogen was introduced 2
to 4 years ago. Additional creeks within the Smith River watershed that were identified in
1995 as being infested include Jones Creek and a small tributary of the North Fork Smith
River near Stone Corral (Del Norte County).
LAMINATED ROOT ROT, Phellinus weirii
- M261A - Klamath Mountains
- A laminated root disease pocket that was previously reported near the Boulder Creek
Trailhead, Klamath National Forest (Siskiyou County), was found to be considerably larger
than originally identified. Multiple coalescing centers in white fir and Douglas-fir cover
an area about 100 acres in size. Mortality and windthrow were occurring in these centers.
Management activities to address the disease are planned in part of this root disease
pocket.
ANNOSUS ROOT DISEASE, Heterobasidion annosum
- M261B - Northern California Coast Ranges
- A large ponderosa pine below Road 210 and north of the Boggs Mountain Demonstration
State Forest office (Lake County) was dying due to annosus root disease. The tree is
adjacent to an annosus monitoring plot.
- M261D - Southern Cascades
- A survey of a bald eagle roosting area on the Goosenest Ranger District, Klamath
National Forest (Siskiyou County), found much of the area affected by annosus root
disease. Numerous annosus root disease centers in ponderosa pine were present and pine
mortality is continuing. Sizeable openings were present and roost trees were being lost.
In addition to annosus root disease, one moist area was affected by black stain root
disease, caused by Leptographium wageneri var. ponderosum.
- M261E - Sierra Nevada
- Annosus root disease was identified in white fir in the McFarland area in southwest
Plumas County, four miles southwest of Meadow Valley. The pathogen was positively
identified in white fir stumps and in blowdown in three stands. The disease is thought to
exist at varying levels in most of the white fir/mixed-conifer stands in the area.
Mortality has resulted when infected trees were subsequently infested with fir engraver
beetles. However, white fir mortality was scattered, and most of the fir appeared to be
outgrowing the effects of the root disease.
- Annosus root disease was responsible for white fir mortality and windthrow in a mixed
conifer stand in the Wallace Canyon area, Georgetown Ranger District, Eldorado National
Forest (Placer County). Approximately 25% of the stand, located at an elevation of 5200
feet, was estimated to be affected. The area was never logged prior to the 1960s and only
logged once since, yet annosus root disease is well established.
ARMILLARIA ROOT DISEASE, Armillaria spp.
- 261A - Central California Coast
- Armillaria, in combination with flathead borers, killed saw timber-sized
Douglas-fir near Scotts Valley (Santa Cruz County).
- 263A - Northern California Coast
- Armillaria root disease and Douglas-fir engraver beetle killed pole-sized
Douglas-fir at the west end of Willits (Mendocino County), and at the west end of Salmon
Creek drainage in Humboldt County. Armillaria also attacked a few Douglas-fir
weakened by Timema douglasi defoliation on Rainbow ridge (Humboldt County). Many
planted Douglas-fir seedlings were killed near Gualala (Mendocino County).
- M261B - Northern California Coast Ranges
- Armillaria root disease killed many seedlings and saplings of ponderosa pine,
Douglas-fir and incense cedar, and small clumps of manzanita, near Loch Lomond (Lake
County). In the same area, a few pole-sized and one saw timber-sized Douglas-fir were
killed. A large American elm near Hopland (Mendocino County) was also killed by
Armillaria.
- M261E - Sierra Nevada
- Armillaria root disease was found on about a dozen dead 10-year old planted giant
sequoia saplings in a plantation on the Hume Lake Ranger District, Sequoia National Forest
(Tulare County). One 49 inch DBH overstory giant sequoia was also killed. In each
instance, the pathogen was present at the root collar of trees that died in 1995 or 1994.
Mortality was restricted to less than one-half acre. To complicate the situation, conks of
Heterobasidion annosum were found in one incense-cedar and one white fir stump
within the pocket of mortality. Armillaria appeared to be the primary culprit, but it is
unknown what triggered this fungus to be so aggressive.
BLACK STAIN ROOT DISEASE, Leptographium wagnerii
- 263A - Northern California Coast
- Several scattered occurrences of black stain root disease were noted in Mendocino County
including: Pine Ridge west of Ukiah; one mile east of Mendocino; Devil's slide area west
of Boonville; near Point Arena Air Force Station; and along Signal Ridge west of Hendy
Woods State Park.
- 261A - Central California Coast
- A large Douglas-fir near Scotts Valley (Santa Cruz County) was killed by black stain
root disease.
- M261E - Sierra Nevada
- Black stain root disease was associated with yellowing crowns, needle drop, stress cone
crops and mortality of pole and small saw timber-sized Douglas-fir in mixed conifer stands
at two separate locations on private land in the Spring Garden Ridge area near Quincy
(Plumas County).
- Black stain root disease was killing two Douglas-firs near State Highway 120 one mile
west of the Big Oak Stump entrance to Yosemite National Park (Tuolumne County). The
affected trees were growing in a densely stocked mixed-conifer stand at about 4400 feet
elevation. Black stain has not been commonly reported in this area of the Sierra Nevada.
DWARF MISTLETOES, Arceuthobium spp.
- M261A - Klamath Mountains
- Dwarf mistletoes continue to affect a wide range of conifer species throughout this
area. Arceuthobium siskiyouense was infecting knobcone pine near Red Mountain on
the Smith River National Recreation Area, Six Rivers National Forest (Del Norte County).
A. abietinum f.sp. magnificae, in conjunction with Cytospora abietis,
was causing tree decline and mortality of red fir stands on South Fork Mountain (Trinity
County).
- M261E - Sierra Nevada
- Moderate to heavy infestations of red fir dwarf mistletoe (Arceuthobium abietinum f.
sp. magnificae) were found in the northwestern portion of the Lake Tahoe Basin
Management Unit (Placer County) north of Burton Creek State Park. Branch flagging was
common on infected fir and assumed to be caused by Cytospora canker. Active fruiting of
Cytospora abietis was observed in mid July at an elevation of about 7400 feet.
- M261B - Northern California Coast Ranges
- Western dwarf mistletoe (Arceuthobium campylopodum) infections on ponderosa pine near
Loch Lomond (Lake County) were severe enough to guide silvicultural prescriptions on a
harvest plan.
- M262B - Southern California Mountains and Valleys
- Western dwarf mistletoe (Arceuthobium campylopodum) continued to heavily infect
Jeffrey pine in recreation areas throughout southern California. The USDA Forest Service
Pacific Southwest Region's "5-Year Dwarf Mistletoe Control Program" is
continuing on the Angeles, Cleveland, Los Padres and San Bernardino National Forests.
Acreages in the 5-year Dwarf Mistletoe Control Program in FY95 were: Angeles - 30 acres,
Cleveland - 60 acres, Los Padres - 85 acres and San Bernardino - 296 acres. Control
measures include broom pruning, branch pruning, thinning and tree removal.
TRUE MISTLETOE, Phoradendron spp.
- M262B Southern California Mountains and Valleys
- True mistletoe (Phoradendron spp.) continued to cause dieback and decline in
black oaks on Liebre Mountain on the Saugus Ranger District, Angeles National Forest (Los
Angeles County).
WHITE PINE BLISTER RUST, Cronartium ribicola
- M261A - Klamath Mountains
- Foxtail pines on Lake Mountain, Klamath National Forest (Siskiyou County), were examined
in 1994 for blister rust. Most of the trees observed had evidence of infection, although
it was light and causing minimal damage. Regeneration and recruitment of foxtail pine was
limited, but it is unknown what effect blister rust is having on this situation.
- M261E - Sierra Nevada
- Blister rust caused conspicuous branch flagging or small tree mortality of sugar pine on
all Ranger Districts of the Sierra National Forest (Mariposa, Madera, and Fresno
Counties), at the University of California's Whitaker Forest (Tulare County), and in the
northern portion of the Lake Tahoe Basin Management Unit (Placer County). At Lake Tahoe,
western white pine growing at 7,450 feet was reported as a host.
- Much of the branch mortality on the Sierra National Forest involved cankers on 1990 and
1991 wood. Some of these infected trees also contained cankers that dated back to the
early 1980s. Dead branches were often 30 feet or more above the ground. Current year
aecia, uredia and telia were not commonly seen. It was common to find branch flagging
restricted to 1995 and sometimes 1994 tissue that was not due to blister rust. The cause
of this flagging remains unknown.
- Branch flagging caused by white pine blister rust was common and very striking on sugar
pines growing on ridge tops, mid-slopes and stream bottoms on the Lassen, Plumas, Tahoe
and Eldorado National Forests.
- White pine blister rust has infected western white pine along the South Fork of Cold
Creek in northern Placer County, 4 miles south of Donner Lake. The heaviest infections
occured on saplings. Occasional cankers can be found in pine taller than 40 feet. The
disease was distributed in the western white pine from South Fork Cold Creek up to the
Pacific Crest Trail. Many mixed conifer stands on the Miwok and Groveland Ranger Districts
(Calaveras and Tuolumne Counties) are heavily infested.
- 263A - Northern California Coast
- One sugar pine sapling with multiple branch flagging was detected near the entrance to
the Point Arena Air Force Station (Mendocino County).
WESTERN GALL RUST, Peridermium harknessii
- 261A - Central California Coast
- Western gall rust infection levels were wiping out a small acreage Monterey pine
Christmas tree plantation near Walnut Creek (Contra Costa County).
- 263A - Northern California Coast
- Isolated stands of planted Bishop pine west of Boonville and planted or seeded Monterey
pine west of Ukiah (Mendocino County) were infected with western gall rust.
MISCELLANEOUS
DRIPPY NUT, Erwinia quercina
- 263A - Northern California Coast
- Interior oaks on the Mendocino College campus (Mendocino County) had bacterial ooze
caused by Erwinia quercina. The bacteria caused dripping from filbertworm-infested acorns
and resulted in an unsightly mess on the campus sidewalks.
HAZARD TREES
- M262A and M262B Central California Coast Range and Southern California Mountains
and Valleys Section
- Hazardous trees, especially coast live oak, continued to be a problem in campgrounds and
recreation areas on the Palomar Ranger District, Cleveland National Forest (San Diego
County), and in Santa Ynez Recreation Area, Santa Barbara Ranger District, Los Padres
National Forest (San Luis Obispo County).
_________________________________
Back to Contents
Status and Control of Animal Pests
A Report to the Forest Pest Council from the Animal Damage Committee
Prepared by: John Borrecco
Introduction
This report summarizes the Animal Damage Committee's annual survey of vertebrate damage
to forest trees. The survey is accomplished by mailing a simple form to private timber
companies, federal and state agencies, and other organizations who manage forested lands
in California. The survey form requests summary information by pest species regarding
species of trees injured, age class of trees, acres over which damage occurs, number of
trees per acre damaged, whether damage occurs in plantations or other areas, the general
trend in damage relative to past conditions, and control methods used. Results of this
survey are reported as part of the California Forest Pest Council's annual overview of
forest pest conditions in California.
In August, 1995, 102 survey forms were mailed to federal and state agencies, private
timber companies, and other private organizations managing forested lands in California. A
total of 43 (42% return) responses were received.
Respondents and Location of Reports
Survey forms were returned by representatives of the U.S. Forest Service (n=17);
California Department of Forestry and Fire Protection (n=7); private timber companies
(n=13); and various other organizations (n=6) including the National Park Service (4) and
the Bureau of Land Management (1).
Incidence of damage to trees was reported from 37 counties representing over 1/2 of the
land area of California. Counties represented: Alpine, Amador, Butte, Calaveras, Del
Norte, El Dorado, Fresno, Humboldt, Kern, Kings, Lake, Lassen, Los Angeles, Madera,
Mariposa, Mendocino, Modoc, Mono, Montrey, Nevada, Placer, Plumas, Riverside, San Benito,
San Bernardino, San Diego, Santa Barbara, Shasta, Sierra, Siskiyou, Sonoma, Tehama,
Trinity, Tulare, Tuolumne, Ventura, and Yuba.
Species Causing Damage
A variety of animal species are causing damage to forest trees and the damage varies by
region of the state and by land ownership (Table 1). Species most commonly identified in
this survey (as well as in previous years) as causing problems are deer (51% of
respondents), pocket gopher (51%), domestic stock (35%), porcupine (28%), rabbits and
hares (21%), black bear (19%), and tree squirrel (14%). Deer, pocket gophers, rabbits and
hares, and livestock feeding injuries on trees occur throughout the State. Damage by other
species tends to be more limited geographically.
Scope Of Damage
Damage from all species was reported on about 475,926 acres (Table 2). All of
California's major timber producing regions and timber types have reported damage by
vertebrate species. Based on the acres of damage, the species ranking changes considerably
from the above ranking and from previous years: woodrat (25% of the acres), porcupine
(23%), black bear (20%), deer (20%), pocket gopher (6%), domestic stock (5%), and all
others (<1%). This change in ranking of species is the result of one new respondent
reporting large numbers of acres affected by woodrats and porcupines. This same respondent
also reported a total of 336,813 acres for four species which also accounts for the
substantial increase in the total acres reported over previous years (2 to 3 times).
Otherwise, the rankings are similar as in previous years.
Table 3. Number of damage responses reported by vertebrate species (N=43).
Species |
USFS |
CDF |
Private |
Other |
Total |
Beaver |
2 |
0 |
0 |
0 |
2 |
Birds |
1 |
0 |
0 |
0 |
1 |
Black Bear |
2 |
2 |
3 |
1 |
8 |
Deer |
13 |
3 |
6 |
0 |
22 |
Woodrat |
0 |
1 |
3 |
0 |
4 |
Elk |
1 |
0 |
1 |
0 |
2 |
Meadow Mice |
1 |
0 |
0 |
0 |
1 |
Mountain Beaver |
0 |
0 |
1 |
0 |
1 |
Pocket Gopher |
14 |
1 |
7 |
0 |
22 |
Porcupine |
8 |
1 |
3 |
0 |
12 |
Rabbits and Hares |
7 |
1 |
1 |
0 |
9 |
Tree Squirrels |
2 |
1 |
3 |
0 |
6 |
Domestic Stock |
12 |
0 |
3 |
0 |
15 |
Feral Pigs |
0 |
0 |
0 |
1 |
1 |
Ground Squirrels |
2 |
0 |
2 |
0 |
4 |
Total |
65 |
10 |
33 |
2 |
110 |
(n) |
(17) |
(7) |
(13) |
(6) |
(43) |
Table 4. Number of acres reported to be receiving some level of damage.
Species |
USFS |
CDF |
Private |
Other |
Total |
Beaver |
2 |
0 |
0 |
0 |
2 |
Birds |
8 |
0 |
0 |
* |
8 |
Black Bear |
310 |
* |
96813 |
0 |
97123 |
Deer |
39975 |
210 |
54140 |
0 |
94325 |
Woodrat |
0 |
0 |
120040 |
0 |
12040 |
Elk |
340 |
0 |
40 |
0 |
380 |
Meadow Mice |
50 |
0 |
0 |
0 |
50 |
Mountain Beaver |
0 |
0 |
* |
0 |
* |
Pocket Gopher |
28724 |
60 |
1410 |
0 |
30194 |
Porcupine |
7815 |
0 |
100140 |
0 |
107955 |
Rabbits and Hares |
1081 |
10 |
200 |
0 |
1291 |
Tree Squirrels |
500 |
* |
1020 |
0 |
1520 |
Domestic Stock |
21826 |
0 |
90 |
0 |
1005 |
Feral Pigs |
0 |
0 |
0 |
1005 |
1005 |
Ground Squirrels |
32 |
0 |
85 |
0 |
117 |
Total |
100663 |
280 |
373978 |
1005 |
475926 |
(%) |
21% |
<1% |
79% |
<1% |
100% |
*incidence of damage reported but no information as to how many acres were affected.
Species Accounts
BEAVER
Species Damaged: Aspen.
Damage Trend: Static.
Control Methods: None (2/2).
Damage Location: Lassen, Nevada, Placer, Plumas, and Sierra Counties.
Comments: Damage reported to pole-sized trees
and to some 3 to 4 year-old aspen in streamside management zones and around
meadows in the northeastern part of the State (M261D Southern Cascades and M261E Sierra
Nevada ecological sections).
BIRDS
Species Damaged: Ponderosa pine.
Damage Trend: Increasing.
Control Methods: None (1/1).
Damage Location: El Dorado County.
Comments: Sapsucker injuries to about 50 small ponderose pine saplings in a mixed
Douglas-fir/ponderose pine plantation (M261E).
BEAR
Species Damaged: Douglas-fir, redwood, white fir, ponderosa pine and western white
pine.
Damage Trend: Increasing.
Control Methods: Sport hunting (3/8), none (5/8).
Damage Location: Del Norte, Humboldt, Madera, and Trinity Counties.
Comments: Damage was reported in both plantations and natural stands to poles and
small saw timber from 10 to 90 years old. Levels of damage vary from 1 to 60 trees/acre.
Black bears are primarily a problem on private timber lands on the north coast of
California in the redwood and Douglas-fir forest types (263A, M261A and M261B ecological
sections). A few incidences of bear damage were reported in the Smith River National
Recreation Area, Six Rivers Nation Forest and on the Minarets Ranger District, Sierra
National Forest in Madera County (M261E).
DEER
Species Damaged: Douglas-fir, redwood, ponderosa pine, Jeffrey pine, sugar pine,
lodgepole pine, western white pine, white fir, red fir, incense cedar, giant sequoia,
canyon and scrub oak.
Damage Trend: Static.
Control Methods: Seedling protectors (13/22),
repellents (5/22), and none (7/22).
Damage Location: Alpine, Amador, Butte, Calavaras, El Dorado, Fresno, Humboldt,
Lake, Lassen, Los Angeles, Madera, Mariposa, Mendocino, Modoc, Mono, Nevada, Placer,
Plumas, Riverside, San Bernardino, Shasta, Sierra, Siskiyou, Sonoma, Tehama, Trinity,
Tulare, Tuolumne, and Yuba Counties.
Comments: Most damage occurs to seedlings 1 to 10 years old in plantations. Levels
of damage reported varied from 5 to 350 trees/acre. Seedling protectors include plastic
mesh tubes and netting. Repellents include BGR and Plant Pro-Tec (garlic units).
Injuries occur in all major timber types in the M261A-B, M261D-G, M262A-B, and 263A
ecological sections.
WOODRAT
Species Damaged: Redwood and Douglas-fir.
Damage Trend: Static.
Control Methods: None (4/4)
Damage Location: Humboldt, Mendocino, and Sonoma Counties.
Comments: Damage occurred to sapling and pole sized trees from 5 to 20 years old at
levels up to 150 trees/acre. Injuries result in dead, spiked tops. Woodrat damage is
primarily reported from private industry lands on the Northern CA coast (263A). One
company reported injuries occurring on 120 thousand acres.
ELK
Species Damaged: Douglas-fir, white fir, ponderosa pine, and Sitka spruce.
Damage Trend: Static.
Control Methods: None (2/2).
Damage Location: Humboldt and Siskiyou Counties.
Comments: Damage occurs to seedlings and saplings 1 to 7 years of age at levels of
25 to 300 trees/acre. Damage most often reported from the Klamath Mountains (M261A) and
Northern CA coast (263A).
MEADOW MOUSE
Species Damaged: Douglas-fir, red fir, white fir, and ponderosa pine.
Damage Trend: Increasing.
Control Methods: None (1/1).
Damage Location: Siskiyou County.
Comments: Damage reported to seedlings 1 to 3 years of age at levels of 50 to 100
trees/acre in the Klamath mountains (M261A) and Southern Cascades (M261D) ecological
sections.
MOUNTAIN BEAVER
Species Damaged: Douglas-fir, redwood, and hardwoods.
Damage Trend: Insignificant.
Control Methods: None (1/1).
Damage Location: Humboldt County.
Comments: Damage observed but considered insignificant. Injuries by this animal are
generally reported from the Nothern CA coast (263A) and coast ranges (M261B), and from the
western part of the Klamath mountains (M261A) ecological sections.
POCKET GOPHER
Species Damaged: Douglas-fir, white fir, red fir, ponderosa pine, Jeffrey pine,
Coulter pine, sugar pine, lodgepole pine, western white pine, pinyon pine, giant sequoia,
incense cedar, deodore cedar, redwood, canyon live oak.
Damage Trend: Static to increasing.
Control Methods: Baiting (9/22), trapping (4/22), vegetation control (3/22),
seedling protectors (1/22), none (9/22).
Damage Location: Alpine, Amador, Butte, Calaveras, El Dorado, Fresno, Humboldt,
Kern, Lassen, Los Angeles, Madera, Mariposa, Modoc, Mono, Neveda, Placer, Plumas,
Riverside, San Bernardino, San Diego, Shasta, Sierra, Siskiyou, Tehama, Trinity, Tulare,
Tuolumne, and Yuba Counties.
Comments: Most damage to seedlings occurs in plantations 1 to 10 years old. Levels
of damage reported range from 1 to 500 trees/acre. Damage occurs throughout all sections
of the Sierran steppe, mixed and coniferous forest and meadow ecological province
(M261A-G), the Central CA coast ranges and Southern CA mountains (M262A-B) and Northern CA
coast (263A).
PORCUPINES
Species Damaged: Douglas-fir, redwood, red fir, white fir, ponderosa pine, and
Jeffrey pine.
Damage Trend: Static.
Control Methods: Hunting (1/12), none
(11/12).
Damage Location: Butte, Calaveras, Fresno, Humboldt, Lassen, Madera, Mariposa,
Modoc, Mono, Nevada, Placer, Plumas, Shasta, Sierra, Siskiyou, and Tehama Counties.
Comments: Injuries occur to seedlings through mature trees in plantations and
natural stands at levels of damage ranging from 1 to 200 trees/acre. Injuries were
reported throughout the Sierran steppe, mixed and coniferous forest and alpine meadow
ecological province (M261A-G) and Northern CA coast (236A).
RABBIT & HARE
Species Damaged: Douglas-fir, redwood, Coulter pine, ponderosa pine, Jeffrey pine,
lodgepole pine.
Damage Trend: Static.
Control Methods: Seedling protectors (4/9), and none (5/9).
Damage Location: Butte, Humboldt, western Kern, Lake, Mono, Plumas, Riverside, San
Bernardino, Shasta, Siskiyou, Tehama, Trinity, and Ventura Counties.
Comments: Damage reported to seedlings 1 to 10 years old in plantations at levels
of 1 to 400 trees/acre. Injuries occurred in Northern CA coast and coast ranges (263A and
M261B), Southern Cascades (M261A), the Central CA coast ranges and Southern CA mountains
(M262A-B), and scattered locations in the Sierra Nevada (M261E) ecological sections.
TREE SQUIRREL
Species Damaged: Douglas-fir, redwood, ponderosa pine, sugar pine, incense cedar,
and big leaf maple.
Damage Trend: Increasing.
Control Methods: Metal bands and hunting (1/6), none (5/6).
Damage Location: Fresno, Mendocino, Nevada, Siskiyou, Sonoma, and Tulare Counties.
Comments: Reports from private forest lands concerned bark stripping and top kill,
especially of redwood poles to mature trees on the northern CA coast (263A). Similar
injuries were reported in Nevada County for Douglas-fir, incense cedar, and big leaf
maple. Forest Service reports concerned cone cutting, especially of rust resistant sugar
pine in the Klamath Mountains (M261A), Southern Cascades (M261D), and Sierra Nevada
(M261E) ecological sections.
DOMESTIC STOCK
Species Damaged: Douglas-fir, redwood, white fir, red fir, Coulter pine, ponderosa
pine, Jeffrey pine, lodgepole pine, sugar pine, western white pine, giant sequoia, incense
cedar, and California black oak.
Damage Trend: Static.
Control Methods: Placement of salt blocks (3/15), seedling protectors (1/15),
herding (1/15), fences (3/15), none (9/15).
Damage Location: Alpine, Butte, Calaveras, Fresno, Kern, Lassen, Madera, Mariposa,
Mendocino, Modoc, Mono, Nevada, Placer, Plumas, Riverside, San Bernardino, San Diego,
Shasta, Sierra, Siskiyou, Sonoma, Tehama, Trinity, Tulare, Tuolumne, and Yuba Counties.
Comments: Most respondents reported damage to seedlings 1 to 10 years old in
plantations. Levels of damage varied from 1 to 200 trees/acre. One respondent reported
browsing by both cattle and sheep, and one indicated that cows primarily cause injury by
trampling seedlings. Cows also damaged riparian plantings following fire. Injuries
occurred throughout the State in the 263A, M261A-G, and M262B ecological sections.
GROUND SQUIRREL
Species Damaged: Coulter pine, ponderosa pine, Jeffrey pine, giant sequoia, red
fir, and white fir.
Damage Trend: Static.
Control Methods: Seedling protectors (1/4); grain baits, smoke bombs and shooting
(1/4); none (2/4).
Damage Location: Fresno, Mono, Nevada, Riverside, and San Bernardino Counties.
Comments: Damage is occurring to seedlings 1 to 5 years old in plantations at levels
of 2 to 500 seedlings/acre. Problems reported in the Southern CA mountains (M262B) and
Sierra Nevada (M261E) ecological sections.
FERAL PIG
Species Damaged: Blue and valley oak.
Damage Trend: Static.
Control Methods: Fence and direct reduction of pigs (1/1).
Damage Location: Monterey and San Benito Counties. (Pinnacles National Monument).
Comments: Consumption of mast and physical destruction of seedlings from rooting
activity in the Central CA coast ranges (M262A) ecological section.
_______________________________________
Back to Contents
Status and Control of Weeds
A Report to the California Forest Pest Council from the Weed Committee
Ken Fleming, Chair
Paul Violet, Secretary
Weed Control Survey
The Weed Committee conducted a survey of private and public forest land managers.
Respondents (66 out of 186 polled) included most large timberland owners in California,
the U.S.F.S Region 5, National Park Service, Glendale Fire District, and forestry
consultants. The survey was conducted to determine the intended purpose and type of weed
control activities that were carried out in 1995. The results are summarized in Tables 5
and 6. As can be seen, both private and public managers performed significant site
preparation and conifer release. Public land managers utilized prescribed burning as a
tool to enhance fire protection. Private land managers relied heavily on chemical
treatments and both public and private managers performed significant amounts of
mechanical/hand treatments.
Table 5. Acres of weed control performed on Private Lands in California - 1995.
Method |
Site Prep |
Conifer Release |
Right of Way |
Research |
Weed Control |
Fire Protection |
Total |
Burning |
7280 |
0 |
35 |
0 |
0 |
140 |
7455 |
Mechanical |
8837 |
3774 |
150 |
70 |
5 |
110 |
12946 |
Hand |
4061 |
8019 |
84 |
0 |
0 |
65 |
12229 |
Glyphosate |
4372 |
11144 |
289 |
5 |
209 |
5 |
16024 |
Hexazinone |
9686 |
8741 |
0 |
2 |
60 |
60 |
18549 |
Triclopyr |
5389 |
24136 |
930 |
2 |
317 |
555 |
31329 |
2,4 D |
2233 |
6248 |
127 |
0 |
0 |
310 |
8918 |
Atrazine |
148 |
1223 |
0 |
0 |
11 |
20 |
1402 |
Oust |
254 |
1655 |
0 |
0 |
0 |
0 |
1909 |
Spike |
0 |
0 |
0 |
0 |
25 |
0 |
25 |
Total |
42260 |
64940 |
1615 |
79 |
627 |
1265 |
110786 |
Table 6. Acres of weed control performed on Public Lands in California - 1995.
Method |
Site Prep |
Conifer Release |
Right of Way |
Research |
Weed Control |
Fire Protection |
Total |
Burning |
3355 |
0 |
0 |
5 |
0 |
22393 |
23753 |
Mechanical |
5302 |
30 |
7 |
3536 |
3984 |
29586 |
42953 |
Hand |
114 |
|
60 |
0 |
265 |
69 |
|
Glyphosate |
803 |
9458 |
3 |
21 |
100 |
0 |
10385 |
Hexazinone |
23 |
964 |
0 |
0 |
0 |
0 |
987 |
Triclopyr |
635 |
7023 |
0 |
0 |
0 |
0 |
7658 |
Total |
10232 |
47031 |
93 |
33 |
3901 |
26446 |
87736 |
![Horizontal Line](https://webarchive.library.unt.edu/eot2008/20090115063738im_/http://www.fs.fed.us/r5/spf/publications/themes/maize/amaizrul.gif)
Back to Contents
Surveys and Evaluations
A Report to the California Forest Pest Council from the Insect and Disease Committees
Demonstration Thinning Plots in the Eastside Pine Type on the Lassen National Forest.
In 1978-1979 the Forest Service established plots in the eastside pine type to show the
effects of thinning on pest-caused losses in areas of high tree mortality. The stands
chosen were mostly pole-size ponderosa pine mixed with some white fir and incense-cedar,
growing on medium to low sites, and ranging in age from 70 to 90 years. Within the
demonstration plots, four levels of stocking density 40, 55, 70, and 100 percent of
normal basal area were established to demonstrate the biological and economic
alternatives available for management planning. (Normal basal area is the basal area that
a stand should have reached when fully stocked with trees, which in the demonstration
areas, ranges from 185 to 215 sq ft/ac, depending on site quality.) Fourteen years after
thinning, the treatments had reduced mortality from 90 to 100 percent of the level in
unthinned stands (Table 7).
Sugar Pine Genetics Program.
In the 1994-1995 screening cycle, 88 mature cone-bearing new parents with major gene
resistance (MGR) to white pine blister rust were identified Regionwide. Progeny of 1,760
candidates (94,080 sugar pine seedlings) were inoculated and evaluated for MGR to white
pine blister rust. Progeny identified with MGR (1,776 individuals) were transplanted to
the Happy Camp disease garden for slow rusting mechanism evaluation.
For the 1995-1996 screening cycle, progeny of 3000 sugar pine families were grown at
greenhouses located at the Placerville Nursery (El Dorado County). These seedlings were
inoculated at 3 months of age. Three hundred and sixteen (316) new rust resistant trees
were identified. The Region has identified a total of 985 mature, cone producing, rust
resistant sugar pine trees in natural forest stands.
All factors indicated that 1995 would be another blister rust wave year over much of
the Sierra Nevada Range. Leaves of Ribes, mostly gooseberry, were covered with blister
rust, and telia were developing well. Observations were made on five, twelve-year-old
evaluation plantations. Infections indicate wave years also occurred in 1989 and 1992.
Some family selections for "slow rusting" resistance to white pine blister
rust were found at Pondorado High School in Camino (El Dorado County). The five acre site
was planted with 96,000 sugar pine trees in 1992. In addition, 27,000 trees are planted at
Happy Camp (Siskiyou County) for slow rusting screening.
Through cooperative efforts between personnel of the Genetic Resource Program and
Sierra Pacific Industries (SPI), thirty-two pounds of rust resistant seed were produced in
the Camino SPI seed orchard (El Dorado County). The seed was divided equally between SPI
and the Forest Service. This seed will be used for reforestation on the Eldorado National
Forest.
Selections of seed from 89 western white, 123 foxtail and 100 white bark pines were
made available to start research on resistance in these species. These same lots are in
stratification for February sowing for development of screening methodology and resistance
identification.
Table 7. Commercial Tree Mortality By Stocking Level, Sixteen Years After Thinning
*
Residual Stocking After Thinning**
Dead Trees Per Acre
Year |
40% |
55% |
70% |
100% |
1980 |
0 |
0.2 |
0.2 |
2.4 |
1981 |
0 |
0 |
0.7 |
2.4 |
1982 |
0 |
0.5 |
0.3 |
3.6 |
1983 |
0 |
0.1 |
0.8 |
4.1 |
1984 |
0 |
0 |
0 |
1 |
1985 |
0 |
0.2 |
0 |
0.6 |
1986 |
0 |
0 |
0 |
1.3 |
1987 |
0 |
0 |
0 |
1.4 |
1988 |
0 |
0 |
0 |
0 |
1989 |
0 |
0.4 |
0 |
2.6 |
1990 |
0 |
0 |
0 |
2.6 |
1991 |
0 |
0 |
0 |
1.8 |
1992 |
0 |
0.2 |
0 |
3 |
1993 |
0 |
0.2 |
0.3 |
5.2 |
1994 |
0 |
0 |
0 |
4.8 |
1995 |
0 |
0 |
0.3 |
0.4 |
Mean |
0 |
0.1 |
0.2 |
2.3 |
Range |
0 |
0-.5 |
0-.8 |
0-5.2 |
Percent Mortality Reduction Compared with Normal Basal Area |
100 |
95.7 |
91.3 |
-- |
*Commercial trees are 8 inches dbh and larger, with straight boles, yeilding at least
one 10 foot long with a 6 inch top. Trees were killed by the mountain pine beetle.
**Percent of normal basal area.
_____________________________________
Back to Contents
Hierarchy of Ecological Units in California
Division |
Province |
Section |
HUMID TEMPERATE DOMAIN |
|
|
260 Mediterranean |
261 CA Coastal Chaparral |
261A Central CA Coast Forest and Shrub |
|
262 CA Dry Steppe |
261B Southern CA Coast |
|
263 CA Coastal Stepp, Mixed |
262A Great Valley |
|
|
263A Northern CA Coast and Redwood Forest |
M260 Mediterranean Regime Mountains |
M261 Sierran Steppe, Mixed and Coniferous Forest and Alpine
Meadow |
M261A Klamath Mountains |
|
|
M261B Northern CA Coast Ranges |
|
|
M261C Northern CA Interior Coast Ranges |
|
|
M261D Southern Cascades |
|
|
M261E Sierra Nevada |
|
|
M261F Sierra Nevada Foothills |
|
|
M261G Modoc Plateau |
|
M262 CA Coastal Range Open Woodland, Shrub, Continuous Forest
Meadow |
M262A Central CA Coast Range |
|
|
M262B Southern CA Mountains & Valleys |
DRY DOMAIN |
|
|
320 Tropical/Subtropical Desert |
322 American Semi-desert and Desert |
322A Mojave Desert |
|
|
322B Sonoran Mojave Desert |
|
|
322C Sonoran Colorado Desert |
340 Temperate Desert |
341 Intermountain Semi-desert and Desert |
341D Mono |
|
342 Intermountain Semi-desert |
342B Northwestern Basin and Range |
Conifer and hardwood vegetation type distribution in California (CALVEG) with domaine
and section lines from the National Hierarchical Framework of Ecological Units.
_____________________________________
Return to Publications page
Go to top of this document