Project leaders: Barbara Bentz

and Jim Vandygriff, USDA Forest Service, RMRS, Logan, UT

Cooperators: Sheri Smith, Tom Coleman and Amanda Garcia, Forest Service, Forest Health Protection; Patricia Maloney and Camille Jensen, UC Davis

Acres with mortality

Source: ADS 2009-2011

• Females initiate attack• Mating occurs under bark• Eggs –

10-14 days• Four larval instars• Pupal stage –

~14 to 30 days

Optimum temperature for development: 23-25° C. No diapause; rely on direct temperature control for seasonality

Hosts:lodgepole

pineponderosa pinewhitebark pinewestern white pinesugar pinelimber pine Coulter pine foxtail pine pinyon pinebristlecone pine(successful in 22 species)

Factors that influence mountain pine beetle phenology:

• Food availability• Resin pressure• Moisture• Predator/parasite

complexes• Temperature

Erich Vallery

Successful across a broad spectrum of latitude and temperature regimes .

Numerous outbreaks recorded the past 100-150 years across western North America

Sandy Kegley

PROJECT OBJECTIVES

• develop a baseline database of mountain pine beetle life cycle timing and associated phloem temperatures in several host trees at multiple elevations and latitudes

• using the field-collected data, evaluate current models of mountain pine beetle phenology

Plots established: 2009

1.Lassen NF: sugar pine near Elam Creek (5364 ft) 2.Tahoe NF: lodgepole

pine near Prosser Creek (5847 ft)3.Lake Tahoe Basin Management Unit: western white pine and lodgepole

pine near Incline Lake (8540 ft), and whitebark pine near Mt. Rose (9619 ft) 4.3) Inyo NF:

limber pine on Granite Pass near Horseshoe Meadow (9600 ft) 5.4) San Bernardino NF:

piñon

pine near Big Bear Lake (6822 ft)

Temperature probes were installed into the phloem on 3 to 5 trees on the north and south bole aspect at DBH.

Temperature probes were attached to dataloggers

that allow for continual recording of temperatures every minute.

MPB tree baits were placed on each tree to initiate attack.

Baits pulled after ~20 MPB attacks.

Ambient temperatures recorded at each site.

MPB attacks were monitored on each tree (between 1 ft and 5 ft) on a daily or weekly basis depending on site.

Cages were placed on trees to monitor emergence.Adult emergence was monitored in the spring, summer and fall (2010 and 2011) on a weekly or bi-weekly interval.

Size and sex of emerging adults were also recorded.

Thermal patterns varied significantly among the sites and between years.

Variability in MPB flight timing and number of attacks on trees among and within trees at each site.

WARMESTSan Bernardino

COOLESTMt. Rose

Num

ber M

PB

0

5

10

15

20

25

30Lake Tahoe Basin MUWestern white pine - 2603m

Num

ber M

PB

0

5

10

15

20

25

30

35

Num

ber M

PB

0

10

20

30

40

50

60

70Lassen NFSugar pine - 1635m

Date in 2009 - 2010June 21 Sept 29 Jan 7 April 17 July 26 Nov 3

Num

ber M

PB

0

20

40

60

80

100

Attacks Emergence

San Bernardino NFPinyon pine - 2709m

Lake Tahoe Basin MUWhitebark pine - 2932m

MPB attacks in 2009 resulted in development in a single year at the majority of the sites.

A proportion of the population at the highest elevation site took two years to develop.

Pre

dict

ed M

PB

Life

stag

e

0

2

4

6

8

10

12OvipositionEggInstar 1Instar 2Instar 3Instar 4PupaeTeneral Adult

Date in 2009 - 2010

July 19 Oct 27 Feb 4 May 15 Aug 23 Dec 1

Obs

erve

d N

umbe

r MP

B

0

10

20

30

40

Observed Attacks ObservedEmergence

Lake Tahoe Basin MU, CAWestern white pine, Incline lake2603 m T4N

Phl

oem

Tem

pera

ture

C

-20

-10

0

10

20

30

MaxMin

Observed phloem temperatures

MPB attacks and emergence

Model predictions

Incline Lake (8540 ft), western white pine

0 100 200 300 400 500 600 700 800

Pre

dict

ed M

PB

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Predicted OvipositionPredicted Teneral Adults

Date in 2009 - 2010 - 2011

July 28

Nov 5Feb 13

May 24

Sept 1Dec 1

0

March 20

June 28

Sept 27

Obs

erve

d M

PB

0

5

10

15

20

25

30

35

observed attacks

observed emergence

Lake Taho Basin MUWhitebark pine, Mt Rose2932m, T1SModel Predictions

2011 emergence predictions are based on 2010 phloem data beginning JD 167, 2011

Phl

oem

Tem

pera

ture

C

-20

-10

0

10

20

30

40MaxMin

Mt. Rose (9619 ft), whitebark pine

Observed phloem temperatures

Model predictions

MPB attacks and emergence

• 2009 attacks = some proportion of beetles that developed in a single year and beetles that required 2 years in the same trees.

• This pattern was predicted by the MPB phenology

model. • Preliminary 2011 field data indicates >90% of brood at the Mt. Rose site will require 2

years to complete a generation.

Pre

dict

ed M

PB

Life

stag

es

0.0

0.2

0.4

0.6

0.8

1.0

1.2 OvipositionEggsInstar 1Instar 2Instar 3Instar 4PupaeTeneral Adult

Date in 2009-2010

June 21 Sept 29 Jan 7 April 17 July 26 Nov 3

Obs

erve

d M

PB

0

10

20

30

40

50

60

San Bernardino NFPinyon pine2079 m T2S

ObservedAttacks Observed

Emergence

San Bernardino

Forced attacks on trees in early June resulted in completion of a MPB lifecycle in less than a year.

Brood in trees at the same site required a full year to complete

their development with emergence the following summer.

Pre

dict

ed M

PB

Dev

elop

men

t

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

OvipositionEggsInstar 1Instar 2Instar 3Instar 4PupaeTeneral Adult

Date in 2009 and 2010

July 26 Nov 3 Feb 11 May 22 Aug 30 Dec 9

Obs

erve

d M

PB

020406080

100120140160180

San Bernardino NFPinyon pine2079 m T5 N

observed attacks observed emergence

south side north side

Preliminary information• Thermal patterns varied significantly among the sites and between

years.

• MPB attacks in 2009 resulted in a univoltine lifecycle at the majority of the sites; a proportion of the population at Mt. Rose developed on a semivoltine lifecycle.

• Completion of a MPB lifecycle on the San Bernardino NF occurred in less than a year in 1 tree; beetles in other trees at the same site required a year.

• The MPB model appears to do well at predicting lifecycle timing in CA.• Predict developmental timing and # generations/year.• Determine how the interaction between beetle, stand and

temperature influence population dynamics.• Predict areas where univoltine/bivoltine/semivoltine

populations are possible under historic, current and predicted climate regimes.

Eggs and small larvae are most susceptible to winter kill.

Eggs and pupae typically do not make it through winter.

Young brood from fall attacksYoung brood at the end of larval galleriesYoung brood of occasional 2nd

attacks are usually more adversely affected than older larvae.

Large larvae are more susceptible to cold temperatures in early spring after feeding has resumed.

Sudden freezing can cause larval mortality at any time.

High temperatures are not likely to cause mortality (>110°F).

• The MPB phenology model will be an additional tool for predicting susceptibility of pine forests to MPB outbreaks across California.

• Development of management strategies. • Prioritize gene conservation efforts (e.g., cone collections, seed-

banking, genetic studies).

In recent years, mountain pine beetle populations have been found further north into British Columbia and east into Alberta than had been observed in historical records,including an outbreak in 1985.

FS-R6-RO-FIDL#2/002-2009

Sandy Kegley

Acknowledgements: Stacy Hishinuma

and Andreana

Cipollone

–

San Bernardino FHP; Brian Knox, Matt Hansen, RMRS;

Funding: Evaluation monitoring, Forest Health Monitoring program, WO

References: Bentz

et al. 1991; Gibson et al. 2009; Logan and Bentz

1999; Powell and Bentz

2009; Amman and Cole 1983.

MPB Model: Regniere, J., J Powell, B. Bentz

and V. Nealis.

Temperature responses of insects: Design of Experiments, data analyses and Modeling.

In Review. Journal of Insect Physiology.

Powell, J.A. and B.J. Bentz. 2009.

Connecting phenological

predictions with population growth rates for mountain pine beetle, an outbreak insect.

Landscape Ecology 24:657-672.

Erich Vallery

USDA is an equal opportunity provider and employer.