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Climate Change and Tree-Insect Interactions:

Effects of Temperature, Drought, and Atmospheric CO2

Dan Herms

Department of Entomology

The Ohio State University

herms.2@osu.edu

Presentation Outline:

• Anthropogenic climate change

• Climate change and pest phenology

• Phenological asynchrony

• Climate change and insect populations

• Climate change and insect distributions

• Insects as agents of tree distribution change

• Atmospheric CO2 and herbivory

Source: NASA GISS

10 warmest years in instrumental record

(16 of 17 have occurred since 2000)

1. 2016

2. 2015

3. 2014

4. 2010

5. 2005

6. 2013

7. 2007

8. 2009

9. 1998

10. 2012Meehl et al. (2009) Relative increase of record high maximum temperatures

compared to record low minimum temperatures in the U.S., Geophys. Res.

Lett., 36, L23701, doi:10.1029/2009GL040736.

Record high temps far exceed record low temps

(if the Earth was not warming the ratio would be 1:1)

Northwest Passage opened for first time in 2007,

and Northeast Passage in 2011

The luxury ship Crystal Serenity, anchored off Nome,

Alaska, in August 2016, on its inaugural Northwest

Passage voyage. “We had to look for ice rather that try

to avoid it,” a passenger said.

Mark Thiessen / Associated Press

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Glacier National Park:

Number of glaciers in 1910: 150

Today: 25

http://www.signoeditoresfotografia.es/wp-

content/uploads/2015/10/GrnRock2_1926_Elrod_U

M486-XII_114-037_c_L.jpg

Grinnell Glacier

1926

2008

New USDA Plant Hardiness Zone Map:

much of Northern US updated to warmer zone

1150 Year Record of Cherry Blossom Phenology

in Kyoto, Japan

Miller-Rushing et al. 2012. Front. Ecol. Environ. 10: 285–290

http://www.citypictures.org/data/media/231/Cherr

y_Blossoms_Ninnaji_Temple_Kyoto_Japan.jpg

http://columbusmmug.com/wp-

content/uploads/2012/07/under-the-Japanese-Cherry-B.jpg

Climate change and phenology

at Sand County, WI

“The mean of regressions for the 55 phenophases

studied was -0.12 day / yr, an overall increase in

phenological earliness…”

Bradley et al. 1999. Phenological changes reflect climate change

in Wisconsin. Proc. Natl. Acad. Sci. 96:9701-9704

CO2 is at highest level (403 ppm) in 650,000 years

www.climate.nasa.gov

Alternative hypotheses considered and rejected by

US National Academy of Sciences

• Earth’s orbit: slight cooling effect.

• Solar activity including cosmic rays: no relation to changes

in Earth’s temperature; atmosphere is warming from

bottom up, not top down.

• Ocean vents: ocean is warming from surface down,

not bottom up.

• Volcanic activity: major eruptions have short-term

cooling effect; minor eruptions have no effect.

• Air pollution: global dimming caused by sulfate

aerosols has cooling effect (but is relaxing).

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Warming projected for US in 21st century:

• 7 - 11°F under high emission scenario

• 4 - 6.5°F under low emission scenario

(USGCRP 2009)

Climate change projections (US EPA)

• Continued warming

• More heavy precip events

• More frequent heat waves and

summer drought

• More days above 95 F

• Northward tree and pest migration

Muilenburg and Herms 2013

Vanessa

Muilenburg

Climate change and pest phenology

Black vine weevil now emerging 2-3 weeks earlier

than in 1970

D.G. Nielsen, Ohio State University

D.G

. N

iels

en,

Ohio

Sta

te

Univ

ers

ity

Gina Penny

Multiflora rose, Rosa multiflora

Implications of Climate

Change for Agricultural

Pest Management

Robin A. J. Taylor John Cardina Department of Entomology Department of Horticulture & Crop Science

Daniel A. Herms Richard H. MooreDepartment of Entomology Human and Community Resource Development

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Phenological Modeling

1. Based on GFDL (NOAA) global circulation

model CM2-SRES-B1 scenario (IPCC-4A)

2. Assumes atmospheric CO2 stabilizes at

550 ppm by 2050

European Corn Borer

one more generation per year range

wide by 2050

www.organicgardeninfo.com

Predicted change in pest status in Ohio

Potato leafhopper: earlier arrival; at least one more generation / yr

Mexican bean beetle: increased overwintering survival; one more

generation / yr

Bean leaf beetle: increased overwintering survival; one more

generation / yr

Armyworm: one more generation / yr

Velvetbean caterpillar: earlier arrival; one more generation / yr

Phenological synchrony Phenological Window Hypothesis(Feeny 1976, Mattson et al. 1982)

- A “window” of time when host traits are most suitable for the insect

- Predicts that insect growth and survival will decline as host-insect synchronicity is modified

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European pine sawfly

(Neodiprion sertifer)

Rodrigo Chorbadjian

One generation each year

Feeds on previous-year needles during a

short window of time

Constrained life-cycle

Winter April May June --- Sept

Hatch cocoon

Insect phenology manipulated relative to natural host phenology

Delayed

bioassays

Advanced

bioassays

Control bioassay:

Natural

hatch

Winter March April May June Sept

0

2

4

6

8

0 5 10 15 20 25 30

Pine phenological stage

[shoot + needle length(cm)]

La

rva

l g

row

th (

mg

/la

rva

) . 2006

2007

As shoots expanded,

food quality declined

Phenological asynchrony

Interacting species with differential responses to

increased temperature.

• Plant - herbivore interactions

• Plant - pollinator interactions

• Predator - prey interactions (e.g. bird migration and

prey availability)

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Ayres, M.P. (1993) Global change, plant defense, and herbivory. Biotic

interactions and global change (eds P. M. Kareiva, J. G. Kingsolver & R. B.

Huey), pp. 75-94. Sinauer Associates, Sunderland, MA.

Changes in temperature during

larval development can affect the

phenological race between plant

and herbivore.

► Mature leaves are of lower nutritional quality than immature leaves

► Insects and leaves have different temperature responses

Phenological race hypothesis

Climate change and insect populations

Developmental times (days) for Tetranychus utricae – two-spotted

spider mite

Developmental stage** Temp. C Egg Larva PN DN PQ Total 15 14.3 6.7 5.3 6.6 3.5 36.3 20 6.7 2.8 2.3 3.1 1.7 16.6 30 2.8 1.3 1.2 1.4 0.6 7.3

Source: http://mrec.ifas.ufl.edu/lso/spmite/b853a3.htm#Table1

Urban Heat Islands and Pests

• Cities up to 10º warmer than surrounding areas.

• Decreased cooling from evapo-transpiration.

• Increased radiant heat.

James Solomon

Oak lecanium 13X more abundant

on willow oaks in hot vs cooler

urban areas

Climate change and insect distributions

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Northward range expansion of

Southern pine beetle into New Jersey

Pinelands

Photo by Bob Williams, Land Dimensions

So far, Pine Barrens

withstanding beetle onslaught

Jan 8, 2012Nov 25, 2010

Apr 10, 2011

June 17, 2011

Southern pine beetle

threatens Pinelands forests

Hordes of the dreaded

Southern pine beetle are

killing New Jersey's forests

N.J. Southern pine beetle

outbreak is nation's worst

M.P. Ayres, Dartmouth College

Kurz et al. 2008. Mountain pine beetle and carbon feedback to

climate change. Nature 452:987-990.

http://www.garna.org/

http://www.for.gov.bc.ca/hfp

Logan and Powell (2001) Amer. Entomol. 47:160-173

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Insects as agents of tree distribution change

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Species co-occurring with black ash in northern MNCo-occurring species in MN that are not predicted to

persist because of EAB or climate change:

Huron River Watershed

White Ash Green Ash Black Ash

Increasing Moisture Gradient

Smith (2006)

>50% Species Dominance

Species co-occurring with black ash in SE MI and NW OH

Predicted black ash replacements based on edaphic

and climate matching:

Climate change, bronze birch

borer, and the distribution of

paper birch

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Drought stress and bronze birch borer

Experimental approach: manipulate water

availability, create simulated outbreak.

Wound-induced periderm (callus) tissue

as a mechanism of borer resistance.

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Hypothesis:

Birch resistance to bronze birch borer is

based on rapid wound-induced callus

formation, the rate of which is dependent on

current photosynthate translocated from

canopy to trunk.

Prediction:

Trunk girdling, which restricts transport of

photosynthate from canopy to trunk, will

decrease rate of callus formation and bronze

birch borer resistance in the portion of the

trunk below the girdle.

Girdling experiment to test prediction:

Four treatments:

Girdled tree:

1) Above girdle

2) Below girdle

Corresponding position on paired control:

3) Above girdle

4) Below girdle

Treatment Effect

Autopsies

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Above girdle:

Below girdle:

Results consistent with hypotheses:

Drought stress decreases paper birch resistance to bronze

birch borer by weakening induced defense responses.

Strong induced stem defenses are dependent on carbon

translocation from canopy to trunk.

Climate change, bronze birch

borer, and the distribution of

paper birch

% of Trees Colonized by Bronze Birch Borer

Vanessa

Muilenburg

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Atmospheric CO2 and herbivory

Paper birch and trembling aspen

CO2: ambient and 560 ppm

O3: ambient and 1.5X ambient

Conservation Biology (1999) 13:700-712

Increased C:N ratio of plants

• Decreased protein

• Increased secondary metabolites

Resulting in

• Reduced insect growth and /or

• Increased compensatory feeding

Herms et al. 1995

Synthesis: Diversity, Distribution, and

Abundance

Elevated CO2 and climate change can have

interacting effects on development rates, host

quality, and nutritional ecology to alter:

• phenology and number of generations

• species distributions

• population dynamics

• ecological interactions

• community composition

• evolutionary trajectories