2015 eastern plant board tcd

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!