Transcript
Thousand Cankers Disease
MitigationScott Myers, USDA APHIS, Buzzards Bay,
MAJackson Audley, UT, Knoxville, TN
Bud Mayfield, USDA Forest Service, Asheville, NC
Adam Taylor, UT Knoxville, TN
Thousand Cankers Disease
• Walnut Twig Beetle (Pityophthorus juglandis) + Geosmithia morbida
• Native to southwest (Blackman 1928, Bright 1981)
• Arizona Walnut (Juglans major) original host (Tisserat et al. 2009, Uty et al. 2013)
TCD in black walnut native range, Knoxville, TN 2010 (Grant et al. 2011)
G. morbida recovered, but not WTB
TCD: Signs and Symptoms
• Galleries + Cankers • Not systemic • Sever nutrient flow• Top-down dieback
Thousand Cankers Disease:
Symptoms
Threat to Black Walnut
• Valuable hardwood o > $500 billion (Newton & Fowler 2009)
o Veneer logs = $$$ (Moltzan 2011)
• Quarantine restrictions industry concerns
Objective• Evaluate treatments for efficacy in eliminating the walnut twig
beetle and Geosmithia morbida from small black walnut logso Heat o Debarking o Methyl Bromide Fumigation
Wood Acquisition 2012 • June, cut 5 trees symptomatic for TCD • Clusters of 90 cm bolts + pheromone lure, sticky cards• Hung in crowns of sympt. trees at 9 locations for 2 months• Distributed 30 cm bolts among treatments using beetle card catch
data
Heat and Debarking• Thermocouple depths
o 1 cm into sapwoodo Core
• Temp. recorded every 1 min• Logs reaching treatment temp at 1 cm
exposed for at least 30 min, removed in 10 min batches (exposure 30-40 min)
1 cm
core
Pathogen Analysis
• 3 bark samples removed per log and examined for cankerso 2011: pre- and post-heato 2012 post-heat
• Chips surface sterilized and plated on PDA
Insect Emergence• Bolts placed in
ventilated plastic containers at room temp.
Proportion of bolts (n=10 per treatment) positive for
Geosmithia morbida
Heat and Debarking 2011: Pathogen Results
Heat 2012: Pathogen Results
Proportion of bolts (n=30) positive for Geosmithia morbida and other fungi after heating to various minimum temperatures for 30-40 min.
Heat Treatment 2012: Mean number of walnut twig beetles emerged per bolt (n=30).
• Why 1 beetle recovered from 1 bolt treated at 56°C?
• Survived the treatment (unlikely)
• Dead near bark surface and dislodged within container
• Landed on bolt between the kiln and the container
control 32 48 64 800.01
0.1
1
10
100
1000
WT
B e
merg
en
ce /
bolt
Methyl bromide initial dose (g/m2)
Walnut twig beetle emergence (mean ± se) following Methyl bromide fumigation at 5°C for 24 hours.
Fumigation 2012: Beetle Results
(448.9)
A B B C
(0.0)
D
(5.8)
(1.5)
(0.8)
Proportion of bolts positive for Geosmithia morbida after fumigation with various doses of methyl bromide at 5°C and 15°C for 24 hrs.
Fumigation 2011: Pathogen Results
Fumigation: Pathogen Results
Proportion of bolts positive for Geosmithia morbida after fumigation with methyl bromide at 5°C for 48 hrs (10 bolts / treatment × 3m reps).
(0) (0)
Confirmatory Pathogen Fumigation: 2013
Proportion of treated and control bolts positive for Geosmithia morbida post treatment.
N =41
N =151
Single treatment of was evaluated at 5C over 48h to confirm efficacy of the 120 mgL-1 dose.
G. morbida was cultured out of several samples, indicating treatment was not 100% effective control MeBr (120
mg/L)
0
0.2
0.4
0.6
0.8
2014: Treatment rate doubled to 240 mgL -1 and still G. morbida recovered from one sample!
Pest Dose (g/m2)
Duration (hrs)
Approx CxT(h*g/m2)
Pine shoot beetle
64 4 220
WTB 80 24 1,400
EAB 112 24 1,580
Pine logs to China
120 16-24 1,800
G. morbida 240 72 ?
Oak logs 240 72 ~12,000
Methyl bromide fumigation schedules for logs at 5 °C
Jackson Audley: Masters Project
Objectives:
1. Identify potential pathways of walnut twig beetle (WTB) in treated black walnut (J. nigra) logs and lumber
2. Identify potential treatments to prevent WTB colonization of logs.
3. Identify potential pathways of WTB in black walnut nursery stock
• Phytosanitation for TCD:1. Steam heat: 52°C for 30 min (Mayfield et al. 2014)
2. Methyl bromide fumigation: 120 mgL-1 at 4.5 °C for 48 hr 3. Kiln-dried lumber, 100% bark removed
• Industry motives: veneer logs & bark on lumber
Post-Treatment Assays: Can WTB colonize treated logs and
lumber?
Extreme Exposure Scenario 5 treatments
1. Steam heated
2. methyl bromide fumed
3. kiln-dried lumber with bark (KDLB)
4. kiln-dried lumber no bark (KDLNB)
5. control
Materials & Methods – Lumberyard Exposure
Scenario
KDLB
KDLNB
Steam
Control
• 4 treatments:o Steam Heato Controlo KDLB - Barko KDLNB – No Bark
• Site: Holston River Farm• 2 Transects:
o A = with WTB Lure o B = no lure
Steam
Control
KDLNB
KDLB
Results – Extreme Exposure Scenario
Results – Extreme Exposure Scenario
Mean (±SE) gallery lengths per treatment
Mean (±SE) life stages per treatment
ANOVA: F2, 87 = 44.70; P < 0.001
ANOVA: F2, 87 = 6.30; P = 0.003
Results – Lumberyard Exposure Scenario
Circular Plot Block
Est. # from Source Bolt
Supp. Releases
Total est. Pressure
1 A 82 40 122
2 A 46 40 863 A 48 40 884 A 1686 40 17265 A 56 40 966 B 7 40 477 B 137 40 1778 B 112 40 1529 B 26 40 6610 B 210 40 250 Total 2810
Total estimated beetle pressure per plot. Total from source bolts plus supplemental releases
Control A
Control B Steam A Steam B KDB A KDB B KDNB A KDNB B02468
101214161820
Total number of samples attacked and mean (SE) emergence by treatment by block
Samples Attacked Emergence
Num
ber o
f Sam
ples
/Bee
tles
Results – Lumberyard Exposure Scenario
Can an insecticides prevent WTB colonization?
• Four treatments:
1.Azadirachtin “Neem” (AzaSol® AI 6%)
2.DOT “Borate” (Tim-Bor® AI 98%)
3.Permethrin (Astro® AI 36.8%)
4.Water (Control)
Materials & Methods
Results: Insecticide Treatment
Efficacy
8hr 24hr 32hr 48hr 56hr 72hr 96hr 120hr0
102030405060708090
100
Azadirachtin 0.003% DOT 15%Permethrin 0.5% Water
Cum
ulati
ve M
orta
lity
%
12hr 22hr 36hr 44hr 58hr 72hr 96hr 120hr0
102030405060708090
100
Azadirachtin 0.013% DOT 30%Permethrin 0.5% Water
Cum
ulati
ve M
orta
lity
%Results: Insecticide Treatment
Efficacy
Conclusions• Topical insecticides promising • Permethrin = effective• DOT (30%) = maybe• Azadiractin = not effective• Future tests
o Other chemicals labeled for use on logso Reduced permethrin rateo DOT “foam” – increased concentration
• Transport of live plants = major pathway of introduction for TCD?
• Will WTB colonize black walnut nursery stock? 1. No-choice Assays
2. Choice Assays
Nursery Stock: Risk of TCD
No-choice Assays
• Trial 1: 5 sources
• Trial 2: 3 sources – NC, MO, OH
• 4 diameter classes – A) 0.5-0.8; B) 0.8-1.1; C)1.1-1.6; D)>1.6
~10 beetles caged on each seedling 5M:5F
Nursery Stock– Choice
Assays
• Seedlings from 5 sources • Trial 1 – 4 June to 19 August
2014• Trial 2 – 20 August to October
17 2014
2 m
2 m
No-choice Assays: Number of Attacks
A B C D A B C DTrial 1 Tial 2
0
0.5
1
1.5
2
2.5
3
3.5
4
A
A
AA
a
a
a
a
Num
ber o
f Att
acks
/100
cm2
ANOVA: F3,32 = 0.68, P = 0.57
ANOVA: F3,32 = 1.10, P = 0.36
No-choice Assays: % Attack
A B C D A B C DTrial 1 Tial 2
0
0.5
1
1.5
2
2.5
3
3.5
4
A
A
AA
a
a
a
a
Num
ber o
f Att
acks
/100
cm2
A B C D A B C DTrial 1 Tial 2
0
10
20
30
40
50
60
70
80
90
100
A
AB
AB
B
a
ab
ab
bPe
rcen
t of S
eedl
ings
Att
acke
dANOVA: F3,32 = 3.74, P = 0.021
DSCF: P = 0.026
No-choice Assays: Probability of
Attack
X2 = 7.31, P = 0.007Max adj. R2 = 0.31
X2 = 6.73, P = 0.010Max adj. R2 = 0.25
Results – Choice AssaysTrial 1 Trial 2
Plot # Est. Beetle Pressure Plot # Est. Beetle Pressure1 33 1 1862 103 2 1153 89 3 454 44 4 3345 86 5 1436 62 6 1087 67 7 668 112 8 859 60 9 149
10 443 10 91Total 1099 Total 1322
No trees attacked in either trial
Conclusions• WTB can attack nursery stock, no-choice
o All diameter classes attacked – prefer >1.5 cm (Seybold et al. 2010)
o No emergence observed, dead larvae found
• No attacks observed in choice settingo No interest? – perimeter traps catch low 23 & 41 per trialo Confounded by exposure method – source as sink?
Summary: Treatments• Debarking
o Not effective – doesn’t remove included bark.
• Insecticideso Have some potential but more products and efficacy data neededo Limited practicality
• Heat o Kiln, ISPM15 and firewood schedules all adequate to mitigate risk of spreading
TCD in wood products.
• Fumigationo Beetles are killed at relatively low rates (>80 mgL-1 at 5 C for 24h)o G. morbida will require a schedule similar to oak wilt for quarantine level
control (~ 240 mgL-1 at 5C for 72 h).
• Vacuum –Steamo Has good potential, but limited efficacy data and infrastructure
Acknowledgements
Robert Camp
Andy Tait
Paul Merten
Bill Klingeman
Sian Bailey
Dillion Alley
Thank You!
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