Bark Beetle Management in Pines - Oregon State Universityextension.oregonstate.edu/...beetle-mgmt-in-pines_jjswa-11-2012.pdf · Bark Beetle Management in Pines ... in western North

Bark Beetle Management in Pines

Bill Schaupp, Entomologist, USDA Forest Service,

Forest Health Protection, Southwest Oregon

Jackson-Josephine Small Woodlands Association,

November 15, 2012

•Supervised by the Resources Staff Officer, Rogue River-

Siskiyou NF with offices and laboratory space

at the J. Herbert Stone Nursery

•Serving southwest Oregon from Cottage Grove to the

California border and the Pacific Coast to the Crest of the

Cascades

•Federal Clients include: Rogue River-Siskiyou and Umpqua

NFs, Coos Bay, Medford, and Roseburg BLM Districts, Oregon

Caves National Monument, Siletz BIA and Tribes served

•Work closely with our partners at ODF and ODA and

collaborate with researchers at OSU, and PSW and PNW

USDA-FS Research Stations

USDA Forest Service, Forest Health Protection Southwest Oregon Forest Insect and Disease Service Center

USDA Forest Service, Forest Health Protection

Southwest Oregon Forest Insect and Disease Service Center

Staff:

Josh Bronson -- Pathologist

(541-858-6124) or [email protected]

Ellen Michaels Goheen – Pathologist and Leader


Bill Schaupp -- Entomologist


Bob Schroeter – Natural Resource Specialist and Aerial Observer


Recent retirees: Don Goheen, Entomologist/Pathologist

Katy Mallams, Pathologist

Frank Betlejewski, USFS Port-Orford-cedar Program Manager

mailto:[email protected]




Presentation Outline

1. Know the pests --- biology and ecology

2. Signs and symptoms

3. Bark beetle management strategies

4. Why thinning works

5. Considerations and cautions

6. Individual tree protection

7. Synthesis

WOODBORING INSECTS

• Primary: Bark Beetles

– Western & Mtn. pine beetle

– Pine engraver (Ips spp.)

– Fir engraver

– Douglas-fir beetle

• Secondary: Woodborers

– Flatheaded & Roundheaded

Woodborers

– Wood wasps

– Ambrosia beetles

Bark Beetles… What are they ??

• Small insects (beetles),

typically the size of a

grain of rice

• Native to local forests

• Integral parts of forest

ecosystems

• Many bark beetles are

tree species specific

WHAT DO BARK BEETLES EAT?

C-shaped larvae

BARK BEETLE DEVELOPMENT

Egg Larva Pupa Adult

What are they doing?

• Bark beetles colonize and kill trees

• They breed, feed and develop beneath the bark

of host trees

• Numbers of bark beetle generations vary

• Beetles introduce wood staining fungi and

bacteria that help disrupt moisture conducting

tissues in host trees

• Beetle populations can expand over short

periods of time, taking advantage of large

areas of susceptible forest

BARK BEETLES • Most important group of forest insects

in western North America

• Despite variety, many common features

1. Opportunistic - infest trees weakened by

other agents and/or factors

2. Communicate chemically - pheromones

aggregate and repel, yield group tree kills

3. Inoculate host tree with fungi and bacteria,

some with essential role in beetle life

4. Most of life spent beneath the bark

BARK BEETLE IMPACTS

• Forest dynamics

• Fire/fuels management

• Timber

• Recreation

• Wildlife

• Hydrology

• Forest Planning – “How many trees will they

kill?”

Bark Beetle

Population

Stand

Conditions

Weather

Conditions

BARK BEETLE DYNAMICS

• Outbreaks are common and driven by many factors

• Stand conditions (density, structure, tree species)

• Moisture levels / climate (drought, temperatures)

• Tree damaging events (storms, fire, defoliation)

Warner Mtns, Southcentral OR

Blowdown, Coastal OR

Pines Stressed by

• Mechanical Injuries

•Lightning

•Fire

•Disease

•Drought

•Old Age

•Competition

BARK BEETLE MANAGEMENT

STRATEGIES

• Alter bark beetle habitat

- thinning, salvage, stress reduction, non-hosts

• Kill beetles

- sanitation, burning infested, trapping

• Protect trees

- chemical pesticides, pheromones

Primary Bark

Beetles of Pines

Western Pine Beetle

(Dendroctonus brevicomis)

Host: Ponderosa Pine

Mountain Pine Beetle

(Dendroctonus ponderosae)

Hosts: All Pines

Pine Engravers

(Ips paraconfusus and I. pini)

HOSTS: All Pines

Smaller diameter material

Tops of larger trees

Breed in newly-created pine

slash

WHERE BARK

BEETLES

ATTACK ……

Evidence of infestation

1

2

3

4

Evidence of infestation (continued)

5

6

7

The Host vs. The Beetles

Pitch Tubes

(not always present)

Boring Dust

Woodpecker

Activity

Bark Beetles

Mountain Pine Beetle

Dendroctonus ponderosae

Western Pine Beetle

Dendroctonus brevicomis

Pine Engravers

What Eats Bark Beetles?


Pine Mortality

In SW Oregon

Are bark beetles

active near you ?

http://www.fs.usda.gov/goto/r6/fhp/ads

Forest Health Monitoring

Aerial Survey Program - Annual tree mortality survey

• Flown annually since 1951

• Cover ALL forested lands in WA and OR

• Same way each year

– 2 observers

– Fixed wing

– 4-mile grid

• Ground-checking for Quality Assurance and Quality Control

• Southwest Oregon data digitized back to 1951

Ponderosa Pine Mortality Attributed to Bark Beetles*

Aerial Sketchmap Surveys Southwest Oregon 1951 - 2004

and

Average Annual Precipitation at Medford, OR Airport

0

5000

10000

15000

20000

25000

30000

51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 95 97 99 01 03

Year

Nu

mb

er

of

dead

tre

es d

ete

cted

0

100

200

300

400

500

600

700

800

900

Pre

cip

itat

ion

(m

m)

dead trees detected

precipitation (mm)

Overall average precipitation = 464 mm

* Western pine beetles, mountain pine

beetles and pine engravers

Relationship of precipitation and bark beetle

infestation of pines in SW Oregon


STRATEGIES



• Kill beetles


• Protect trees


SILVICULTURAL

MANAGEMENT

Promote host vigor!

Manage stocking levels below thresholds

Thin, under-burn, or both in overstocked stands

Basal Area Thresholds For Elevated Risk of

Pine Bark Beetle Infestation in

Southwest Oregon

Ponderosa Pine - poor to moderate sites = 80 ft²/acre

Ponderosa Pine - high sites = 120 -150 ft²/acre

Sugar or Western White Pines

on Ultramafic Soils = 80 ft²/acre

Sugar or Western White Pines

on Non-Ultramafic Soils = 140 - 180 ft²/acre

Basal area thresholds for bark beetle risk are site dependent

1 acre

Basal area: the cross-sectional area of tree stems

measured at breast height and expressed per unit

of land area [e.g. square feet per acre = ft²/acre]

Thinning across pine

stands or stand

components

Thinning around

individual pines

Tree Crown

Pines Need Space!

Clump of Pines

~same age/cohort

Give the clump space

Pines Need Space!

<13 rings per inch •Higher vigor

•Less susceptible to bark beetles

>13 rings per inch •Lower vigor

•More susceptible to bark beetles

Assessing tree vigor by measuring number of rings per inch (most recent growth)

using an increment core

Second growth ponderosa pine

Non-declining growth rate •Higher vigor

•Less susceptible to bark beetles

Declining growth rate •Lower vigor

•More susceptible to bark beetles

Assessing tree vigor by determining growth rate (most recent growth)

using an increment core

Mature/old growth ponderosa pine

THEN…

1914-1924

<0.5 percent per year

Present

1.0 to 3.0 percent per

year

Ashland Experimental Station

Bureau of Entomology

WHY

Now

MANAGEMENT

Promote host vigor!

Manage stocking levels below thresholds

Thin, under-burn, or both in overstocked stands

Pine Engravers

Manage Slash!!

Options for Pine Engravers

Remove or burn slash before beetles complete life cycle

Reduce risk by treatment design:

- Time thinning appropriately

- Avoid shaded slash piles near hosts

- Lop and scatter slash in the open,

exposing it to the sun

- Pay particular attention to large

diameter slash (> 3 inches diameter)

Using prescribed fire

1997 2010

Plot 8, Survey Pine 436

10 feet

25 feet 25 feet

Control Compressed radius clearing

Extended radius clearing Extended radius large tree retention

N = 58

N = 55

N = 58

N = 58

Based on results so far in the Wolfpine study:

It appears that thinning around large sugar pines contributes to increased

growth, decreases likelihood of bark beetle infestation, and promotes sugar

pine regeneration.

On sites with ridge tops exposed to high winds, stem breakage can be a

sugar pine mortality factor. It seems less of a factor where thinning has

been done with retention of one to several large trees around a large sugar

pine than in unthinned stands or situations where sugar pines are exposed

by themselves in wide openings.

Among treatments, the extended radius clearing with reserve trees retained

shows evidence of being the best for the objective of retaining large old

sugar pines in mixed stands, while at the same time promoting adequate

new sugar pine regeneration.


STRATEGIES



• Kill beetles


• Protect trees


WESTERN PINE BEETLE

Dendroctonus brevicomis

• Affects ponderosa pine in two ways

– Scattered mortality in larger trees (>20”dbh)

– Clumped mortality in small diameters

• Strongly associated with drought

conditions or fire damage

• Increased mortality of large & small

ponderosa in recent years (assoc. w/ MPB)

– Long-term damage trends similar

to that of fir engraver

WESTERN PINE BEETLE

What to look for • April-September

– Fine boring dust in bark crevices

– Appearance of small pitch tubes

(1/4-1/2” diameter) on bole

– Pitch tubes may appear multiple

times (2-4 generations/yr)

• September-March

– Foliage of successfully attacked

trees fades (pale green-yellow-orange)

– Attacked trees change from fall to spring

– Woodpecker activity (bark removed) or

presence of beetle gallery (S-shaped

patterns etched into sapwood)

WESTERN PINE BEETLE

Infestation characteristics

• Usually 2 generations per year

– 3-4 possible in southern OR

• Sapwood shows dark staining

– Associated with blue-stain fungus

introduced by beetles

• Operations can increase susceptibility

– Soil compaction or mechanical damage

• Often associated with other beetles

– Pine engraver in upper crown

– Mountain pine beetle on lower bole

– Red turpentine beetle at root collar

WESTERN PINE BEETLE

Management

• Silvicultural

– Thin stands according to site index

recommendations

(See OSU Extension Guide)

• Sanitation and Salvage

– Remove newly infested trees during

winter (contain the most live beetles)

• Individual tree protection

– Spray high-value trees with insecticide

(up to 30’ on stem) prior to spring flight

– Sprays during summer can also reduce attacks

(expensive & requires re-application)

MOUNTAIN PINE BEETLE

Dendroctonus ponderosae

• Endemic / low levels normally occur

• Scattered mortality of often stressed / damaged pines

• Outbreaks initiate in older, overstocked lodgepole stands

• > 60 yr old; Avg. > 6” dbh; Basal area >100 ft2

• 5-needle pines also highly susceptible

• Ponderosa pine usually a more “resistant” host

• Outbreaks continue and intensify (highly variable)

• Sustained by abundance of susceptible lodgepole pines

• Large numbers overwhelm more resistant hosts

• May persist >10 yr and cause significant mortality


What to look for • Similar to other pine bark beetles

• Pitch tubes on tree bole

(1/2 - 1” in diameter)

• Rapid foliage change

(off-green / yellow / red)

• Galleries parallel to wood grain

(long 12-36”, J-shaped end)

• Presence of life stages


Management in Forests

• Natural controls

• Host depletion

• Severe freeze in fall / spring

• Prolonged cold conditions

• Predators / parasitoids unable

to control outbreaks

• Silvicultural strategies

• Remove infested trees

(containing live beetles)

• Thin overstocked stands

(OSU Extension Guides:

lodgepole vs. ponderosa?)

Clerid beetle

MOUNTAIN PINE BEETLE Management of High Value Trees

• Chemical treatments for individual tree protection

• Bark cover sprays most effective treatment to date

• Systemic applications remain inconclusive

• Variable results with repellent pheromones (Verbenone)

Pheromones

Systemics

Cover spray

PINE ENGRAVERS

Ips spp.

• Hosts include most pines

– Ips pini in Central-Eastern Oregon

– Ips paraconfusus (CA 5-spined Ips)

in western Oregon

• Multiple generations

– 1st generation infests small diameter

down materials (storm breakage, slash)

– 2nd-4rd generation can attack

sapling to pole-sized trees

• Aggressive during drought years

– Long-term trend more variable,

often affects young plantations

PINE ENGRAVERS

What to look for

• March-October

– Orange-brown boring dust in bark

crevices of slash / down wood

– Adult beetle present (spines on abdomen)

– Galleries radiate out from a central

chamber (Y- or H-shaped, 5-10”)

• July-August

– Rapid changes to crown

(yellow to reddish-brown)

– Prefer slash, but if not available

may attack young trees (3-8”dbh)

or cause top-kill in older trees

PINE ENGRAVERS

Infestation characteristics

• Usually 2 generations per year

– 3-4 generations in Southern OR

• Populations build-up in fresh slash or

storm breakage/blowdown

– Following generations cause mortality

– Damage increases when spring moisture

<75% of normal levels

• Operations often linked to damage

– Creating/ abundant >3” dbh slash

during late winter-early summer

– Piling slash in shade or near tree base

PINE ENGRAVERS

Management

• Silvicultural

– Do not leave abundant slash >3” dbh

during the early flight period

– Scatter slash in openings to dry or

dozer-trample/use slash-buster

– Cover / tarp slash piles tightly

– “Green chain” method (create

continual supply of slash)

• Individual tree protection

– Spray high-value trees using

insecticide (up to a 3” top)

– Multiple generations require

re-application (expensive & time-consuming)


STRATEGIES



• Kill beetles


• Protect trees


INDIVIDUAL TREE PROTECTION

Protective Cover Sprays

• Only preventative, not curative

• Kills adults as they penetrate bark

• Need proper timing / good coverage

• Registered “ornamental” products in OR

• Carbaryl (Sevin)

• Permethrin (Astro)

• Bifenthrin (Onyx)

• Need experienced applicator

• High-pressure equipment

• Applied to run-off up to 4”

• May need re-application

PROTECTIVE COVER SPRAYS Fettig, et al. 2006

• Objective

• Evaluate efficacy of Bifenthrin (Onyx) and Carbaryl (Sevin)

for protection of high-value Western pines

• Methods

• Cover sprays for MPB, Western pine beetle, and Ips confusus

• Trees baited to initiate attacks (>50% control mortality)

• Findings • High variation but significant

reductions in tree mortality

(Sevin: Avg. 7% mort.; 2-yr protection)

(Onyx: Avg. 20% mort.; 1-yr protection)

• Issues with contract applicators

PROTECTIVE COVER SPRAYS Fettig, et al. 2008

• Objective

• Evaluate drift of carbaryl (Sevin) during protective cover

sprays of individual trees

• Methods

• Assessed drift at 4 distances

(20, 50, 75, 100’) from bole

• Evaluated potential damage

to aquatic species

• Findings • 97% of total spray deposition

remained within 50’ of bole

• Application efficiency approx. 80%

• No-spray buffer of 25’ sufficient for most aquatics

• No-spray buffer of 75’ for more sensitive spp.

• Ongoing evaluations for bark beetles

• Do sufficient levels reach phloem (?)

• High variation by tree species

• Delivered via stem or soil

• Imidacloprid (Pointer, Merit)

• Emamectin benzoate (Tree-äge)

• Requires experienced applicator

• Reduces threat to non-targets

• Potential multi-year protection

• Can be time-consuming and

expensive

INDIVIDUAL TREE PROTECTION

Systemic Insecticides

SYSTEMIC TREATMENTS Grosman, et al. 2010

Emamectin benzoate was effective in providing protection of P. ponderosa

from D. brevicomis during the third year following a single application…These

results are promising, but additional tests are required before we can

conclude that emamectin benzoate is an effective preventative treatment for

any bark beetle – host system.

“To our knowledge, this is the first demonstration of the

successful application of a systemic insecticide for

protecting individual conifers from mortality due to

bark beetle attack in the western United States.”

http://www.fs.fed.us/psw/publications/fettig/psw_2010_fettig(grosman)001.pdf

STRIVING FOR IPM

The Goal

• Natural

• Are natural mortality factors at work or expected?

• Endemic population phase vs. outbreaks?

• Silvicultural

• Tree species, densities, etc. appropriate for site?

• Have contributing factors / stressors been addressed?

• Biological / Chemical

• Are biological products / options recommended?

• What is the relative value of tree or resource?

• Can chemical treatments be used safely / effectively?

CONCLUSIONS

• Pine bark beetles can cause substantial

impacts

• Stands, stand components, or individual

trees that are at high risk are identifiable

• Management treatments exist

• Should be integrated in management

strategies to attain objectives

• Integration with fire and fuels management

STUDY REFERENCES

• Fettig, C.J., K.K. Allen, R.R. Borys, J. Christopherson, C.P. Dabney, T.A.

Eager, K.E. Gibson, E.G. Hebertson, D.F. Long, A.S. Munson,

P.J. Shea, S.L. Smith, and M. I. Haverty. 2006. Effectiveness of

bifenthrin (Onyx ) and carbaryl (Sevin SL) for protecting

individual, high value trees from bark beetle attack in the western

United States. J. Econ. Entomol. 99: 1691-1698.

• Fettig, C.J., A.S. Munson, S.R. McKelvey, P.B. Bush, and R.R. Borys.

2008. Spray deposition from ground based applications of carbaryl

to protect individual trees from bark beetle attack. J. Environ. Qual.

37: 1170-1179.

• D. M. Grosman, C. J. Fettig, C. L. Jorgensen, and A. S. Munson. 2010.

Effectiveness of Two Systemic Insecticides for Protecting Western

Conifers from Mortality Due to Bark Beetle Attack. W. Jour.

Applied Forestry 25(4): 181 – 185

ACKNOWLEDGMENTS

• USDA-Forest Service

• Oregon State University

• Oregon Dept. of Agriculture

• Industrial & Private Cooperators

• Photos: ForestryImages.org, USDA-FS Archives & ODF

*Further Information available from:

Oregon Department of Forestry, Forest Health Unit:

Rob Flowers, Entomologist, [email protected]

Website: http://www.oregon.gov/odf/privateforests/fh.shtml

Oregon State University – Extension Service:

Dave Shaw, Forest Health Specialist, [email protected]

Website: http://extensionweb.forestry.oregonstate.edu/

USDA Forest Service, Forest Health Protection

Bill Schaupp, Entomologist, [email protected]

Website: http://www.fs.usda.gov/goto/r6/foresthealth

Aerial Survey Group, Regions 5&6

And if there is time and/or interest, more

info on other insects of import follows…

WOODBORERS

• Generally secondary agents that

attack dead/dying trees

• Large number of species

– Flatheaded borers (Buprestidae)

– Roundheaded borers (Cerambycidae)

– Wood wasps (Siricidae)

– Pinhole borers - Ambrosia beetles

(Trypodendron, Gnathotrichus spp.)

• Extensive galleries, often extend into

sapwood & heartwood

– Impact wood quality & value

– High-profile non-native species

FLATHEADED BORERS

• Many conifer & hardwood hosts

• What to look for

– Galleries are S-shaped & packed with

fine boring dust in concentric crescents

– Emerging adults leave “D-shaped”

or oval exit holes

– Adults often metallic with short antennae

• Exception: Flatheaded fir borer acts as

a tree-killer in Douglas-fir

– Attacks mature trees on low-elevation,

drought-prone sites

– Fire damaged trees very susceptible

Flatheaded fir

borer

(Phaenops

drummondi)

Public

Enemy

Number One!

0

100

200

300

400

500

600

700

800

900

0

10000

20000

30000

40000

50000

60000

70000

An

nu

al p

reci

pit

atio

n (

mm

)

Nu

mb

er

of

de

ad t

ree

s d

ete

cte

d

Year

Douglas-fir Mortality Attributed to Flatheaded Fir Borer Annual Aerial Sketchmap Surveys 1974 - 2011

and Annual Precipitation 1971-2010

Medford International Airport, Medford, OR

Number of dead trees detected Annual Precipitation Average Annual Precipitation

ROUNDHEADED BORERS


• What to look for

– Larval galleries are S-shaped & loosely

packed with coarse boring materials

– Emerging adults leave circular exit holes

– Adults usually have long antennae

(also called “longhorn” beetles)

• Native woodborers often confused

for non-native species

– Fir sawyer & Banded alder

borer (right) often mistaken

for Asian longhorn beetles (left)

WOOD WASPS (Horntails)


– Tunnel through sapwood & heartwood

– Larvae have spine on tip of abdomen

– Adults wasp-like with projection on

abdomen (longer on females)

• Non-native wood wasp (Sirex noctillio)

of increased concern

– Significant damage when introduced

to new areas

– Recently detected in Eastern US

– Trapping & monitoring underway

in Western US

AMBROSIA BEETLES


– “Pinhole” tunnels & dark staining

in sapwood

– Abundant fine boring dust produced

– Do not feed on wood, but construct

tunnels for growing fungus

– Adults are very small (2-5 mm)

• Greater damage in wetter/coastal

areas of Oregon

– Can quickly degrade wood quality

– Often survive pre-export treatments

(Potential invasive species)

INVASIVE SPECIES: CURRENT EFFORTS

• Oregon Invasive Species Council,

– “100 Least Wanted” published annually

• ODA Trapping & Inspections

– Gypsy moth, Nun moth & Japanese

beetles (pheromone traps)

– Asian longhorn beetle & European

wood wasp (surveys & inspections)

– Emerald ash borer (trap trees, traps)

– Granulate ambrosia beetle (traps)

• No detections in 2011 in OR

– Recent gypsy moth eradication projects

in Bend, Shady Cove, & Eugene

Documents

Bark Beetle Management in Pines - Oregon State Universityextension.oregonstate.edu/...beetle-mgmt-in-pines_jjswa-11-2012.pdf · Bark Beetle Management in Pines ... in western North