Forest Pests
Forestry & Society
Fall 2003
J.G. Mexal
Forestry & Society
Trees Live A Long Time/PNW,2000
Lifespan (yrs)
1200
1000
800
600
400
200
0
Human
Paper
Birch
White
Spruce
Ponderosa
Pine
Sitka
Spruce
Redwood
Forestry & Society
Forest Health/PNW,2000
“A healthy forest can renew itself vigorously
across the landscape, recover from a wide
range of disturbances, and retain its
ecological resilience while meeting current
and future needs of people for values, uses,
products, and services.”
USDA Forest Service, 1997
Forestry & Society
Pest Outbreak Triangle/PNW,2000
Forestry & Society
Forest Pests• Exotic Pests
• Native Pests
• NM Pests
Forestry & Society
Forest PestsPest Species Migration
• 1869: Gypsy moth – Asia?-- E. Hardwoods
• 1898: White pine blister rust -- Europe to Idaho to
NM -SW white pine
• 1904: Chestnut blight -- Japan –
American chestnut (50% mortality by 1930)
• 1929: Dutch Elm Disease -- Europe –
American Elm (77 million killed in 20th century)
• 1980s: Asian long-horn beetle -- China – E.
hardwoods
• 1990s: Pinewood nematode -- Japan -- Western
conifers
American chestnutOriginal Distribution
• Occupied 25% of
Appalachian hardwood forest
• Largest DBH = 17 ft
• Japanese chestnut imported
by Bronx Zoo in 1904
• Not TES because of stump
sprouts
• Susceptible to P. cinnamoni
Forest Pests
Chestnut Blight - Dryphonectria parasitica
• From Japan 1904
• Eliminated American chestnut from
eastern deciduous forests.
• Annual lost timber value for 3 states of
$683.9 million (1999 dollars).
• Caused declines in chestnut-dependant
wildlife and erosion where lost trees have
not been replaced.
American chestnut- a comeback?
Original Distribution
Forest Pests
White Pine Blister Rust Cronartium ribicola
1920
1925
1935
Current
Forest @ risk
Late 1800’s throughout range of eastern white pine and
early 1900’s in 6 western. Killing pines in western high elevation
ecosystems, eliminating wildlife forage; affecting soil stability, snowmelt.
Forest Pests
White Pine Blister Rust Spread
Historic
Current
Dutch Elm Disease- Ophiostoma ulmi
• Discovered in 1930 from Europe
• Occurs in most states. Killed
more than 60% of elms in urban
settings.
• A more virulent U.S. strain
evolved and has caused
significant impacts in Europe.
Forestry & Society
Forest Pests-Gypsy moth
Millions of Acres
14
12
10
8
6
•Lymantria dispar brought to
Boston, MA in 1869 for silk
industry .
•Infests 15 states in NE US
•Feeds on oak, sugar maple,
beech and aspen
4
2
0
1940
1950
1960
1970
Year
1980
1990
2000
Gypsy moth found in Travis Co., TX/2005
•In 19 states, spot infests 12 more.
•Annually defoliates millions of northeastern and
Midwestern forested acres;
•Suppression costs tens of millions.
•Record losses in 1981: 13 million acres defoliated; $3.9
billion (1998 dollars) in losses.
Asian gypsy moths such as this male, left, and female attack more than 500 plant species.
Forestry & Society
Emerald Ash Borer (Agrilus planipennis)
Could cause elimination of ash as a street,
shade, and forest tree nationwide at an
estimated cost of $282 billion.
Imported from Asia
Infested Canada, MI (1999) & OH & MD
Killed 6kk trees in MI alone (2002-2004)
David Cappaert
Forestry & Society
Emerald Ash Borer (Agrilus planipennis)
D.G. McCullough, Tree
Farmer (Mar/Apr 2006)
• Discovered in 2002
• All ash species susceptible
• 12-15kk ash trees killed in
central MI by 2006
• Threatens 8kkk forest trees
(valued @ $282 billion)
• Threatens 3.8kkk urban trees
Photos by David Cappaert
Exotic Pests
• Emerald Ash borer:
–
–
–
–
Established in Michigan in 2002
Established in Ohio in 2003
Established in Indiana in 2004
Established in Illinois in 2006
• Area = 40,000 square miles
• 3 billion trees vulnerable
• Removal & replacement costs ~ $7 billion
Forest Pests
Sudden Oak Death = Phytophthora ramorum
•Discovered in 1994 in CA
•In 2005, spread to OR, WA, GA, LA, TN, SC
http://www.invasivespecies.gov
•In 2006, found in 22 states
•84 susceptible species in US
•Calif. black oak
•White fir
•Calif. red fir
•Coastal redwoods
•Coast live oak
•Douglas-fir
•Madrone
•Tanoak
•Could devastate oak forests nationwide.
Joseph O'Brien
Forestry & Society
Exotic Pests/Balsam Woolly Adelgid/
PNW,2000
Native to Western Europe
Discovered on West Coast
in 1929
(Adelges piceae) 1908
Attacks true fir species.
Caused dramatic
declines in Fraser fir in
Great Smoky Mountains
National Park, resulting
in understory and
wildlife changes.
Subalpine fir 1965
Forestry & Society
Exotic Pests/Hemlock Woolly Adelgid/
(Adelges tsugae) 1920’s from Asia.
Currently in more than 4 states.
Contributing to decline of eastern
and Carolina hemlocks. Alters bird
communities where it kills eastern
hemlock.
Forestry & Society
Forest Pests-Asian Longhorned Beetle
Photos by M. Smith
Forestry & Society
Pine Knot Nematode on Scots Pine
• Native to Japan
• Discovered in
1979 in MO
• Carried by pine
sawyer beetle
• No control
Pinus sylvestris
Nebraska Forestry Service
SNC Aerial Survey /Greg Filip
1996
1997
Forestry & Society
Exotic Pests/Weeds Science Findings 38/Oct’01
• SE
kudzu
cogongrass
• NW
English ivy
Holly
Scots broom
Himalayan blackberry
Sweet cherry
Forestry & Society
Exotic Pests/Weeds Science Findings 38/Oct’01
• SE
kudzu
cogongrass
• NW
English ivy
Holly
Scots broom
Himalayan blackberry
Sweet cherry
Forestry & Society
Exotic Pests/Weeds Science Findings 38/Oct’01
• SE
kudzu
cogongrass
• NW
English ivy
Holly
Scots broom
Himalayan
blackberry
Sweet cherry
Forestry & Society
Exotic Pests/Weeds
Yellow starthistle competes with mariposa lily
PNW Sci. Update 9:2:Mar’05
Forestry & Society
Exotic Pests/Weeds Science Findings 38/Oct’01
Cover (%) after 3 yrs
2nd Growth Douglas-fir
100
80
Natives
Exotics
VDT creates
openings for
invasion by
exotics
60
40
20
0
Old Growth
Control
Old Growth
VDT
Thinned
Control
Treatment
Thinned VDT
VDT = Variable density thinning
Forestry & Society
Forest Pests• Exotic Pests
• Native Pests
• NM Pests
Forest Pests
Mountain Pine Beetle
British Columbia
•Started in 1998
•Attacked Lodgepole pine
•Area = 9 kk ha
•Value = $9kkk
•2007:
•Area = 15,000,000 ha
•Volume = 530 kk m3
•Value = $38 kkk
•40% of BC pine forest
Ministry of Forests
1 m3 = 1 telephone pole
Forest Pests
Mountain Pine Beetle
Will climate change
spell the end of
forests in North
America?
A warmer climate
allows the beetle to
migrate north and
potentially east and
then south!!!
Spruce beetle spread in Kenai Peninsula, AK/
PNW-RP-563, ‘05
van Hees
Forest Pests
Spruce Bark Beetle J. For. 104(5):254:’06
• Beetle-killed spruce in Alaska
• Over 1 million acres destroyed (90%
mortality)
Bark beetle outbreaks in Texas/
SJAF 27(2):122:2003
Infested Acres
10000
Managed - Controlled
Wilderness- No Control
1000
100
Chemical control
does not work! It’s
too late!
10
1
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
Forest Pests
Billboard in Florida/ J. For. 104(5):241:2006
Forestry & Society
Forest Pests-Western Spruce Budworm
Millions of Acres
7
6
5
4
Choristoneura occidentalis
is native to Rocky Mountains.
Feeds on Douglas-fir and
true firs.
3
2
1
0
1940
1950
1960
1970
Year
1980
1990
2000
Forestry & Society
Forest Pests-Oak Wilt
• Oak wilt = Ceratocystis
fagacearum
–
–
–
–
oaks (Quercus)-- 36 species
chestnuts (Castanea)
chinkapins (Castanopsis)
tanoak (Lithocarpus)
Discovered
in 1995
J.For. 99(5):4:’01
Forestry & Society
Forest Pests-Oak Wilt
Healthy
Dead
J.For. 99(5):4:’01
Forestry & Society
Forest Pests-Oak Wilt in Texas
Cost ($1,000s)
Acres
16000
14000
12000
10000
10000
8000
6000
6000
4000
2000
0
1986
2000
1988
1990
1992
1994
Year
1996
1998
2000
2002
J.For. 99(5):4:’01
Red-Headed Pine Sawfly
• Enemy of young pine
plantations
• Usually completely
defoliates a tree before
crawling to the next
• Destroys trees because
there is more than one
generation of eggs laid
Forestry & Society
Forest Pests-USFS Expenditures
• Insects
–
–
–
–
–
–
Gypsy moth
Mtn pine beetle
So. pine beetle
Hemlock woolly adelgid
Ips beetle
Spruce beetle
• Weeds
• Disease (oak wilt)
$3.8 million
$1.1 million
$ 315,000
$ 116,000
$ 42,000
$ 10,000
$ 285,000
$ 270,000
J.For. 99(5):4:’01
Forestry & Society
Forest Pests in New Mexico
• Bark beetles
– Dendroctonus
– Twig beetle
– Ips
• Wood borers
– Roundhead
– Flathead
• Mistletoe
– True (Phoradendron)
– Dwarf (Arceuthobium)
•
•
•
•
•
Western Spruce budworm
Tent caterpillar
Cytospora canker (aspen and willows)
Douglas-fir tussock moth
White pine blister rust
Forestry & Society
Forest Pests- Review Questions
• Describe the pest outbreak triangle
• Why and how do these exotic pests get
introduced and started?
• What are the major forest pests in the US?
In NM?
• How are they controlled? Does it make
sense? Why?