Walnut in the West Death by a Thousand Cankers

Walnut in the West Death by a Thousand Cankers
•
•
•
•
•
•
Colorado State University
– Ned Tisserat, Whitney Cranshaw, Curtis Utley, Emily Freeland, Bill Jacobi
Boulder County CO ‐ Kathleen Alexander
CO State Forest Service‐ David Leatherman
USFS California ‐Steven Seybold
UC Davis ‐ Andy Graves; Chuck Leslie
Institute Perennial Plants for Food and Bioenergy (IPPFB), UT
–
•
•
•
•
•
•
T. Ford, R. Funk
USFS Purdue‐Keith Woeste
U Missouri‐ Mark Coggeshall
U Tennessee‐ Scott Schlarbaum
Oregon State – Jay Pscheidt
Czech Republic – Miroslav Kolarik
Funding USFS, USDA‐CSREES
Black Walnut (Juglans nigra)
• Not native to western USA
• Not a major component of urban landscape but it is a tough tree
– Street trees
– Backyards
– Farmsteads
• Trees can grow to very large sizes in Oregon
– Also have hybrids
Black Walnut Decline and Mortality in Utah in 90’s
•
•
•
•
Walnut twig beetle collected near Salt Lake City UT in 1988; but walnut mortality not reported until 1990’s
"If I get a little personal and even a little sentimental, I hope you will forgive me," President Hinckley said as he began to describe the origin of the pulpit. "Every year at this season we planted trees," he said. "Well, some 36 years ago I planted a black walnut. It was in a crowded area where it grew straight and tall to get the sunlight. A year ago (1999?), for some reason, it died." "The first time I saw the wood was when Brad had the log in the back of his pickup truck,“ (Intermountain Wood Products of Salt Lake UT)
Walnut pulpit in Mormon
Conference Center
Black Walnut Decline and Mortality in Oregon (1990’s?)
• Always associated with presence of twig beetle
• Progression slower than in Colorado?
• Reasons?
•
•
•
•
Walnut hybrids common?
Larger trees?
Thicker bark?
Different weather (less stress)?
Note symptomless walnut at end of row
Extensive Mortality In New Mexico 2001
• Elimination of black walnut near Santa Fe
– Walnut twig beetle found
• Reports of dieback in Albuquerque 2009
– Thousand cankers disease (TCD) confirmed in 2010 Black Walnut Mortality in CO
• Walnut decline first observed in Colorado Springs and Boulder around 2001‐2002
– May have been years earlier in western Colorado (90’s)
• Substantial mortality in Colorado Springs and Boulder by 2004
– Walnut twig beetle and drought suspected
• Black walnut eliminated in Colorado Springs by 2008
• Well over 2,000 trees dead in Denver‐Boulder and surrounding area; few surviving trees in Boulder
Red Areas indicate where Geosmithia and Pityophthorus
juglandis have been found since 2008
Initial Symptoms Subtle and Easily Confused With Other Problems
May See Resprouting But Sprouts Also Succumb
September 2008
June 2008
June 2009
Walnut Twig Beetle
Pityophthorus juglandis
• Walnut twig beetle found in Colorado 2003 on black walnut
• First record of insect on Juglans major in New Mexico (1927)
– native to the Southwest?, California?
– Twig beetles normally attack small, weakened twigs
Range of Juglans major
Identification of Walnut Twig Beetle,
Pityophthorus juglandis Blackman
OCD: Almost compulsive
(Coleoptera: Scolytidae)
Slide courtesy
boring and tasting
S. Seybold
An “Über” Vector of TCD
Two rows of tubercles
behavior on host branches
Concentric arcs of
asperities
The walnut twig beetle is a
minute bark beetle.
It is one of few
Pityophthorus species
that develop in
hardwoods.
Great picture by Jim LaBonte,
OR Dept. Agriculture!
Pityophthorus bark
beetles are collectively
known as “twig beetles”
because they normally
restrict damage to small
diameter twigs.
Walnut Twig Beetle
• Very aggressive on black walnut
– Most galleries on branches >1 inch diameter
– Attacks will occur on main trunk
• Entrance holes very difficult to see
J. regia
• Trapping is very inefficient using yellow traps or Lindgren funnels
• Most beetles caught in late summer
Beetle Captures
45
40
35
30
25
20
15
10
5
0
How Does Such a Small Beetle Kill Such A Big Tree?
Summer 2007- Coalescing cankers consistently
noted around beetle galleries
• Beetle galleries and cankers not evenly distributed on branches or trunk
– More damage on lower side of branches
– More damage on one side of trunk?
• Often west side of tree more damaged?
• # galleries and cankers on tree is enormous!!
East side of trunk
West side of trunk
Cankers Initially Restricted to Phloem and Don’t Extend into Cambium
Outer bark
Phloem
Eventually Cankers Will Kill Cambium
Cankers on Walnut (Left) Differ From Open‐
Faced Cankers (Ash Tree on Right)
Summer and Fall 2007 – fungus consistently isolated from cankers
Geosmithia ‘morbida’
• Anamorphic genus
– (Ascomycota:Hypocreales)
– No sexual state known
• Off‐white to buff in culture, often lobed
• Dry conidia – Unlike Ophiostomatoid
and ambrosia fungi (e.g. in Raffaelea in Laurel wilt)
• Thermotolerant
– Optimal 25‐32 ⁰C
– Will grow at 37 ⁰C (99 ⁰F)
– Will survive 42 ⁰C (107 ⁰F)
Geosmithia ‘morbida’ has a yeast phase
Geosmithia species associated with numerous beetles in Europe but has not been reported as plant pathogen
Geosmithia species
G. fassatiae
G. langdonii
G. obscura
Geosmithia OTU’s
Insect
Scolytus intricatus
Scolytus rugulosus
Scolytus intricatus
Scolytus rugulosus
Ernoporicus fagi Scolytus multistriatus
Scolytus intricatus
Scolytus carpini
Ernoporus tiliae
Hylesinus orni
Ips typographus
Scolytus schevyrewi
Trypophloeus
Xyloborinus saxeseni
Xylosandrus mutilatus
Host
Quercus spp.
Malus
Quercus spp.
Malus
Fagus
Ulmus
Quercus
Carpinus
Tilia
Fraxinus
Picea
Ulmus
Populus
Ulmus
?
Geosmithia also has been isolated from A
B
frass, beetle galleries, and beetles
Photo courtesy Dr. A. Graves
U.C. Davis
Acremonium alternatum AY566992
G.
puterillii
AF033384
0.92
G. sp. 27 RJ0911
0.92
AJ578485 OTU2
AJ578487 OTU5
RJ137m
1.00
0.70
G. pallida
CCF3638 OTU23
0.98
AJ578488
OTU3
species
complex
0.49
0.71
AJ578486 G.pallida type
MK1758
0.94
„G. rubra“ AM181464 OTU1
0.78
0.86
1.00 G. sp. 20 CCF3641
„G.
adriatica“
CCF3655 OTU10
0.94
„G. rufescens“ MK1803
0.92
G. lavendula AF033385
G.sp. 26 MK1797
G. obscura AJ784999
0.97
G. obscura AM181460
G. sp. 8 AM181420
„G. microcorthyli“ CCF3861
0.90
0.75
G. sp. 16 AM181422
G. sp. 35 RJ167m
G. sp. 32 MK1801
G. sp. 30 MK1824
0.82
0.95
G. sp. 30 RJ156m
0.82
G. sp. 33 MK1809b
G. sp. 34 MK1832
0.55
0.70
G. sp. 31 MK1793
G.langdoni AJ578481
G. flava AJ578483
G. fassatiae AJ578482
0.50
1247 CO
1217 CO
0.88
1234 AZ
1227 CA
0.65
1270 CA
1222 UT
G. “morbida”
1259 OR
1239 CO
0.94
1223 UT
1273 CO
1269 CA
0.89
Pinaceae
1218 CO
G. sp 11 AM181419
G. sp. 29 CCF3753
G. sp. 21 MK592
0.53
G. sp. 12 AM181431
0.42 0.74
G. sp. 13 AM181439
1.0 1226 FortCollins CO
G. sp. 40 CCF3563
Angiosperms
Isolate from S. schevyrewi
„G. eupagioceri“ CCF3754
from
Ulmus
+ Cupresaceae
G. sp. 9 CCF3703
G. sp. 25 MK1805
G. sp. 28 RJ278m
0.79
G.
sp.
44
MK1804
0.84
G. sp. 22 CCF3652
G. sp. 24 MK1822
0.69
0.1
Analysis courtesy
M. Kolarik
It’s a Food Fight!
A
• Bark maceration
• Pityophthorus, ambrosia beetles, other insects
• Geosmithia, Fusaria & many other fungi
B
Fusarium Canker of Walnut
• Reported in 80’s in Minnesota, Wisconsin, Kansas following harsh winter conditions
• Associated with ambrosia beetles
Death by a Thousand Cankers
• Initial beetle attack
– Cankers form around beetle galleries, but initially localized in phloem
– Cankers coalesce, eventually penetrate bark to cambium; resulting in branch dieback
– It may be years between initial beetle attack and visible symptoms
• The death spiral – Tree vigor declines
– Mass attack by beetles on trunk; many cankers
– Secondary fungi invade (Fusarium solani and others)
– Trees are killed Distribution of 1000 Cankers in Colorado
rDNA ITS haplotypes of G. morbida
are not geographically or host specific
Where Did 1000 Cankers Originate?
• Pityophthorus juglandis and Geosmithia ‘morbida’ widespread on J. major in New Mexico and Arizona
– But our survey is not complete
• J. major not in a state of decline in its native range
• Do isolates vary in aggressiveness to black walnut?
– not so far
What about the California Walnuts?
J. californica
J. hindsii
Thousand Cankers Disease: Areas of Interest in CA
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Thousand Cankers Disease: Areas of Interest in CA
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Thousand Cankers Disease: Areas of Interest in CA
Davis, Yolo Co.: Branch dieback and
mortality on Juglans hindsii on city streets
and along rural highways, June-Aug., 2008
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Thousand Cankers Disease: Areas of Interest in CA
Winters, Solano Co.: Northern
California black walnut is dying
in its native habitat in the lower
Sacramento River Valley
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Thousand Cankers Disease: Areas of Interest in CA
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Davis, Yolo Co.: Black walnuts
are dying in research germplasm
collections, e.g., UCD Walnut
Collection and NCGR. Mortality
of a 12-13 yr old Juglans californica
on Paradox Rootstock, Aug. 11, 2009
Thousand Cankers Disease: Areas of Interest in CA
Piru Lake, Ventura Co.: Native endemic
stands of Juglans californica in the
Los Padres National Forest showing
crown dieback and tree mortality, Aug. 27, 2008
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Thousand Cankers Disease: Areas of Interest in CA
Near Glendale, Los Angeles Co:
Highly symptomatic native
Juglans californica in a
residential backyard,
Montecito Heights, June, 2009
J. regia
J. regia
J. regia
J. hindsii
J. californica
Slide Courtesy of A.D. Graves,
UC-Davis Dept. Plant Pathology
Black Walnut vs. Pecan Is Juglans regia at Risk?
Two dead Juglans nigra on left, healthy Juglans regia on right
Photo courtesy Marion Murray, Utah State University
Juglans regia (Denver) in fall 2008 and June 2010. Juglans microcarpa in Denver 2010
Butternut (J. cinerea) in Denver area 2010
Susceptibility of other Juglans, Carya
species?
Juglans microcarpa
Inoculations
Juglans major
Juglans nigra
Canker Development Following Inoculation With Geosmithia
Discolored Area (mm2
160
140
PDA
120
Aspergillus
100
Geosmithia Isolate 1217
80
Geosmithia Isolate 1218
60
40
20
0
Tree Species in Order of Susceptibility to Geosmithia
Discolored area 6 wk after inoculation; mean of 6 trees
2,000
**
**
% increase in discolored area
Inoculated vs. control
1,500
**
1,000
**
**
**
500
NS
NS
NS
NS NS
NS
NS
NS
**
NS
**
**
**
**
**
NS
0
1,500
**
1,000
**
**
**
**
**
NS
*
500
**
**
NS
*
NS
NS *
NS
NS
NS
NS
NS
0
C.ovata
C.illinoensis
J.major
J.californicaB
J.hindsii
J.microcarpa J.californica
Isolate 1217
Isolate 1218
J.regia
J.cinerea
J.ailantifolia
J.nigra
1000 Cankers Poses Grave Risk to Walnuts
• Dieback and decline of Juglans
spp. in California
• Rapid mortality of black walnut in numerous regions of the West
– Disease widespread
– Very efficient, aggressive vector
– Aggressive fungus
• What happens if disease establishes in native range of black walnut?
– What if it doesn’t/ can’t cause damage in native range?
• Can we take that chance by ignoring this?
It Will Be Too Late To Do Anything if TCD Establishes in Native Range
• Other exotics introduced into native range of susceptible trees
– Butternut canker
– Chestnut blight
– Emerald ash borer
– Laurel wilt
• TCD is not yet in native range: we can do something
Can We Contain 1000 Cankers?
Do We Have the Will to Contain It?
Beetle infested black walnut with bark attached
as advertised on the internet
What Should We Do Nationally?
• Walnut wood harbors the insect and fungus
• We don’t know for how long, but moving wood is a very bad idea!
Over 23,000 beetles emerged from these logs
How wood might move
Black Walnut Makes For Great Firewood in Colorado (and elsewhere)
No One in the West Wants to Destroy Infested Logs!
Denver Craigslist Postings (10/29/2009)
 ‘I have a full truckload of black walnut wood’ ‘We have a straight, tall walnut tree, lost to disease, that needs to come down. We thought we'd offer it up to woodworkers before having it hauled off for firewood.’ For sale ‐ 3 stunning walnut crotch slabs. 1 bookmatched set and one other sequential slab all from the same log. These were recently cut so they are still green, you buy green, you save a pile of green. Transcontinental Movement of Large Logs
• Myth that logs are not shipped from West to East
What About Bark Removal?
• Beetles apparently emerged from wood and then tried to reenter logs
• Debarking may not be a safe measure
• Some woodworkers don’t like bark removed
What about chipping?
Walnut twig beetles
were able to complete
development in larger
pieces following
chipping
Right Now We Need To Prevent Movement of ANY Form of Wood! What About Chemical Treatments?
• Not a solution to the long term survival of black walnut in native range
• May have some use in the West
What About Drenching Sprays?
• Drenching branch sprays (pyrethroids and others) for walnut twig beetle has not been effective ‐
possibly because of poor timing Soil treatments and Walnut Twig Beetle
• Imidacloprid (Merit) use in Boulder may have slowed progression, but did not always save diseased trees
– However, most applications made curatively rather than preventively
– Need higher rates?
• Trials planned for Denver in 2010
– Imidaclorprid, abamectin, possibly others
– Dinotefuran may work better for this application, but doesn’t have food crop tolerance
– What about fungicides?
What Needs to Be Done
• Strong public education on the threat of Thousand Cankers Disease to black walnut in its native range
– Arborists, Woodworkers, Homeowners
– http://www.colostate.edu/Depts/bspm/extension
%20and%20outreach/thousand%20cankers
– htmlhttp://mda.mo.gov/plants/pests/thousandca
nkers.php
–
• Information What Needs to Be Done
• Immediate restrictions on the movement of walnut wood
– State quarantines
– National quarantines
• We must stop this!
Containment of 1000 Cankers
• Don’t move infested logs or lumber with bark attached
• Sanitation in infested areas probably won’t help
• Movement of fresh debarked lumber?
• Movement of wood chips?
Average Canker Area in mm2
Average Geosmithia Canker Size
Utah Study 100
90
80
70
60
50
40
30
20
10
0
Geo. Iso. 1222
Geo.Iso. 1223
Juglandaceae Species inoculated
‘Those who do not remember the past are condemned to repeat it’ Black Walnut (Juglans nigra) in the • Not native to West
western US
• Not a major component of urban landscape
– Street trees
– Backyards
– Farmsteads
• It’s a tough tree!
Oregon
March 2008‐ Canker formation in black walnut 8 weeks after inoculation with isolates of Fusarium solani and Geosmithia ‘morbida’
Isolate
Fusarium solani 917
Number of inoculation Average and range ( )
sites developing
of canker lengths (mm)
cankers
2/8
19.0 (16-22)
Fusarium solani 1179
6/8
21.0 (10-40)
Geosmithia 1217
8/8
57.0 (29-130)
Geosmithia 1218
8/8
46.5 (31-60)
A
B
F. solani
G. morbida
Geosmithia is a bark, and not a vascular pathogen
Canker formation 4 weeks
after inoculation in field (Utah),
original inoculation point 3 mm diam.
Adult twig beetle tunneling on excised stem of Juglans nigra after 24 hours
Canker development 4 weeks after placement of adult twig beetles on excised stem of Juglans nigra
Other Canker Fungi
• Very long, vertical cankers on trunk during final stages of decline
• Fusarium solani
isolated from cambium in 2006 (but not from around beetle galleries)
– Other Fusarium
species have also been recovered
Dead Walnut Wood Can Host Bark Walnut
twig beetles readily breed in logs
Beetles and Fungus
Two logs, ca 5 1/2-in diameter, 18-in length
23,040 Beetles/2 logs
= 35+
Beetles/inch2
2006 in Boulder Colorado
Open‐Faced Cankers Don’t Form
• May see bark cracking around entrance holes, star shaped wounds at leaf scars, and staining on trunk, but these are not diagnostic Could Walnut Twig Beetle Kill the Tree Without Geosmithia?
• Geosmithia always associated with insect
• Does the fungus enhance the ability to attack Pityophthorus to attack bark?
– Reduced vigor? – beneficial to insect?
Where Did G. morbida Come From?
1234 AZ
1263Ventura CA
1264Ventura CA
1261SanJoaquin CA
1276CSUOval CO
1217Boulder CO
1279Wheatridge CO
1224Boulder CO
1249YoloCounty CA
1227Winters CA
1273GoldenCemetery CO
1236Prosser WA
1250Boulder CO
1270SanJoaquin CA
1267SanJoaquin CA
1260 OR
ITS rDNA sequencing
1245Boise ID
1262Ventura CA
3
1223 UT
1268Ventura CA
1274Wheatridge CO
1218Boulder CO
1
1269Ventura CA
1258 OR
1
1228Winters CA
1272Ventura CA
1259 OR
1247ColoradoSprings CO
1
1233YoloCounty CA
1256 OR
1266Ventura CA
1246ColoradoSprings CO
1285Delta CO
65
1222 UT
1239Westminster CO
1271GoldenCemetery CO
0.0002
• Isolates vary slightly in DNA (rDNA ITS) sequence
– Suggests at least some genetic diversity
– Probably not the result of a single introduction?
Juglans Germplasm Collection
Positive Isolation of Geosmithia from English Walnut, J. regia,
Accession No. DJUG0366.1, Block C, Row ?, Tree 1, September 2009
1) Mass attack by walnut twig
beetle
Red Areas indicate where Geosmithia and Pityophthorus juglandis have been found