Arthropods in Agricultural Landscapes: Challenging and...

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Nancy Schellhorn Principal Research Scientist Team Leader – Spatial Ecology Arthropods in Agricultural Landscapes: Challenging and Supporting Food and Fibre Production AGRICULTURE FLAGSHIP

Transcript of Arthropods in Agricultural Landscapes: Challenging and...

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Nancy Schellhorn Principal Research Scientist Team Leader – Spatial Ecology

Arthropods in Agricultural Landscapes: Challenging and Supporting Food and Fibre

Production

AGRICULTURE FLAGSHIP

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Presentation title | Presenter name | Page 2

‘Despite a clear increase in pesticide use, crop losses have

not significantly decreased during the last 40 years’ (Oerke, 2006, J Ag Sc)

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Yield loss (pre-farm gate) and efficacy of control

(Oerke, 2006, J Ag Sc)

Loss

Pre-harvest 18%

+ post-harvest = 37%

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Increasing Food Demand Global challenges (Keating et al 2014):

1. Reducing food & fibre loss

2. Minimizing degradation of Ag landscapes

3. Reducing farm inputs

Entomology

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Key message:

Entomology will be part of the solution

• Connect scales

• Demonstrate impact

Global challenge of food & fibre demand

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Presentation title | Presenter name | Page 6

Arthropods are habitat linkers!

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Spatial & Temporal Scale

Population processes occur at various spatial scales

Stiling & Strong 1982, Heads & Lawton 1983; Weins & Milne 1989; Thies & Tscharntke 1999; Bommarco & Banks 2003, Schellhorn

& Andow 2005; Tscharntke et al 2005; Schellhorn et al 2015 (in press)

Temporal scales

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Farming Practices

Presentation title | Presenter name | Page 8

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Measures of Impact

Must be linked to the management objective

Examples are many and varied but must provide

evidence of:

• lesser problem

• greater savings

• science-based solution is being adopted

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• Movement • Landscapes • Farming practices

Research approach:

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Presentation title | Presenter name | Page 11

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OUTLINE: 2 examples - global challenges

1. Link between perennial habitat and crop pest control

Minimizing degradation of Ag landscapes

2. Moth behaviour across cotton / grain landscapes

Reducing Farm Inputs

Reducing food & fibre loss

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Thies & Tscharntke 1999, Science

Seminal paper – Landscape Structure and Biological Control in Agro-ecosystems

Meligethes aeneau

Ichneumonidae

Tersilochus heterocerus,

Phradis interstitialis,

P. morionellus

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What’s the global state of play 15+?

> 65 Studies rl/sp landscape metrics (% area) and

abundance and diversity of NE

Trend is positive – higher abundance and diversity of NE

with higher % non-crop habitat;

Most studies = NE abundance and diversity – a few

measure pest suppression;

Demonstrates a clear link b/t spatial scales -- field, farm &

landscape.

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The ‘problems’ and gaps

Schellhorn et al Insect Sci 2015

Strong focus on NE abundance / diversity & landscape

Need more examples of pests abundance & landscape

Most Northern Hemisphere;

Need examples from Asia;

Need more examples that integrate farming practice with

landscape ecology studies

Several have demonstrated pest suppression = pest control

Need evidence of > control or > savings; evidence of impact (Chaplin-Kramer et al 2012; Jonnson et al 2012; Rusch et al 2013; Costamanga et al 2014 (in press))

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1. Link between perennial habitat and crop pest control

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Presentation title | Presenter name

|

Bethugra, NSW

Ex. 1. The problem: Focus has been on pest and natural enemies in crops – not other habitats in landscape.

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Method

Landscape

Year/ Month

Sites

Region

Crop Near

Sites

Native Veg.

Weeds

Sites

Monthly Samples

F M A M J J A S O N D J F M A M J J A S O N D

2009 2010

Crop Far Sites

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Ex. 1. The solution: Where are pests and predators found?

Pest = Region (40%) (F2,282=209.92 P<.001 ) and habitat type (31%) (F2,282=163.01 P<.001 )

Predators = 50% habitat type alone (F2,282=159.46 P<.001)

Bianchi et al, 2013; Ag & For Ent ; Parry et al, 2015, Basic & App Ecol (in press)

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In native remnants, on which plant species are they found?

Pests = 47% of the variance was explained by plant type alone (F2,154=72.59 P<.001)

Predators = region (35%) (F2,152=67.03 P<.001 ) and plant type (4%) (F2,152=8.12 P<.001 )

Bianchi et al, 2013; Ag & For Ent; Parry et al, 2015, Basic & App Ecol (in press)

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The solution: When are they there?

Photo credit: Keith Power, Beatsheet

Adult Nymph

Rutherglen Bug Nysius vinitor

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NSW: January-March 2010

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NSW: April-June 2010

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NSW: July-September 2010

canola

canola

canola

canola

canola

canola

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NSW: October-December 2010

canola

canola

canola

canola

canola

canola

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More weeds in pastures = more Rutherglen bug juveniles

0

25

50

75

100

0.5 2.5 3 5 7.5 15 35 50weed percentage

Mea

n de

nsity

of r

gbJ

per

m2

Me

an

Ruth

erg

len b

ug juvenile

s p

er

m2

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The Solution: When are they there?

0.0

100.0

200.0

300.0

400.0

500.0

Tota

l per

mo

nth

m2

NV Adult

NV Juv

0

100

200

300

400

500

600

Jan

Feb

Mar

ch

Ap

ril

May

Jun

e

July

Au

g

Sep

t

Oct

No

v

De

c

Jan

Feb

Mar

ch

Ap

ril

May

Jun

e

July

Au

g

Sep

t

Oct

2010 2011

Tota

l per

mo

nth

m2

Canola Adult

Canola Juv

Wheat Adult

Wheat Juv

Photos credit: www.goodbugs.org.au

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Pe

st d

en

sity

Time

Theory predicts: Early arrival of predators results in better pest suppression

Settle et al. 1996; Ives & Settle 1997; Landis & van der Werf 1997; Bianchi & van der Werf 2003; Bianchi et al 2009

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Sentinel plants (1000’s+)

The solution: Is pest suppression greater in fields near remnant veg patches compared to far?

Melon

Whitefly

nymphs

Cotton

Helicoverpa

eggs

Darling

Downs

Landscapes

simple

complex

X 19

Lockyer

Valley, QLD

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Period

Para

sitoid

s p

er

pla

nt

0.0

0.1

0.2

0.3

0.4

0.5

2007

2008

Early Mid Late

Remnant Near Far

0.0

0.2

0.4

0.6

0.8

North

South

Pa

rasito

ids p

er

pla

nt

Cotton

Bianchi et al. Ag, Ecosys, & Env (in review)

Darling

Downs

Spatially and temporally erradict

Significant factors - % NV @ 1km; TRT; Period; Year

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0 5 10 15

0

50

100

150

surv

ivin

g a

phid

s

% Lucerne at 2 km

Land-use predictors – Aphid predation

aphids = 70.29 - 5.29 (% Lucerne 1.5K); Adj. r2 = 0.37

Melon

% Lucerne 1.5K Costamanga et al. Ecol Appl (in press)

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Adj r2 = 0.41

Sources of Insect Predators

Costamanga et al. Ecol Appl (in press)

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Snap shot - Data Summary

Think beyond the crop -- Landscape context matters!

Native vegetation clearly provides

habitat for beneficials, especially

important out-of-cropping season

Weeds harbour pests, and some

beneficials;

Perennial pasture and lucerne plays key

role in landscape for beneficials AND for

pests if pasture is degraded and weedy!

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Presentation title | Presenter name 35 |

Parry et al., Basic

and Applied Ecology

(in press)

Relative benefit of a plant species

Predator Dominated

Pest Dominated

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Presentation title | Presenter name

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Lower for Longer

Pest suppression

Schellhorn et al. Insect Science 2015 – Special Feature

Pest control

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Presentation title | Presenter name | Page 38

Summary Ex. 1:

Link Conservation Biology

& Agricultural Production

? IMPACT

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2. Helicoverpa spp moth behaviour across a landscape

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Helicoverpa armigera

[GLOBAL PEST]

and H. punctigera

159 host spp,

~85 HA & HP

~34 HA (monocots) (Zalucki et al 1986)

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Bt Cotton (Bollgard®)

Helicoverpa armigera & H. punctigera

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0

2

4

6

8

10

12

95/9

6

96/9

7

97/9

8

98/9

9

99/0

0

00/0

1

01/

02

02/

03

03/

04

04/

05

05/

06

06/

07

ac

tiv

e in

gre

die

nt

(kg

pe

r h

a)

Conventional INGARD Bollgard II

IMPACTS of GM based IPM - Insecticide Reductions

Ist generation Bt cotton

44% reduction

2nd Generation Bt Cotton

85% reduction

Data courtesy of GP Fitt

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The Problem: Reduction in insecticide use depends on: 1. continued effective Resistance Mngt Plan;

and 2. biological control for other Helicoverpa

susceptible crops across landscape.

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Queensland, Australia

Darling Downs,

Field data collection

Cotton

Sorghum

Maize

Pigeon Pea

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Bt Cotton Other host crops

(e.g. Sorghum)

SINK

Grasses

SOURCE

Ha only

Helicoverpa armigera

and H. punctigera

Mandated Refuge

(Pigeon Pea)

SOURCE

Ha & Hp

159 host spp,

~85 HA & HP

~34 HA (monocots) (Zalucki et al 1986)

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Mandated Refuge (% of Bollgard Cotton)

• 5% Pigeon Pea

• 10% Unsprayed conventional cotton

• Within 2km of Bollgard Cotton

Planting Windows

Pupae Busting

$170-230 Ha

(seed, H2O,

cultivation, herbicide)

$2000-2800 Ha

(gross margin of cotton)

(pers. comm. Dr Paul Grundy)

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hypotheses E

gg

de

nsity

0 100

% Bt Cotton (km)

H. Armigera only

% Sorghum (km)

Eg

g d

en

sity

0 100

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100 %

of crop

1 2 6 5 4 3 8 7

fields

Selecting Fields for Sampling & Characterizing Land Use / Land Cover

sorghum

Bt cotton (sink)

Corn

Pigeon pea

26 different land use categories were

mapped for each landscape using Arc GIS

185 ha

30 ha

8 Bt cotton fields

3 landscapes

5 years

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Parasitized

H. armigera

H. punctigera

Helicoverpa spp

Infertile

Unviable

Parasitized unknown

Counted

Collected

a sub-set

Fates determined:

(23,819)

(15,934)

Eggs tell us about

female

moth behaviour

Eggs in Bt cotton tell

us about colonization

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Summary of spatio-temporal data

•Three landscapes

•Five Years

N C P N C P N C P N C P N C P

09/10 10/11 11/12 12/13 13/14

Drought Big Flood Regular Flood Drought

Bt cotton sorghum pigeon pea

Egg data: Approx 36,000 eggs counted;

20,000 eggs collected - fates for Helicoverpa

spp. and egg parasitoids.

Moth data -Sweep Net data: Caught and

disturbed Helicoverpa spp (♀ moths caught

12/13 and 13/14 dissected )

Moth data - Pheromone trap data: ♂

Helicoverpa both spp. approx 6000 traps deployed

75000 male moths caught

Pupae dig data: Helicoverpa spp. associated

parasitoids (5th instar = trigger) 15 sites

Moth data - UV Solar light trap data: 64 traps rpt

3 x for one landscape. Total 192 traps

♀Helicoverpa moths spp. dissected (approx 90

moths)

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PAMPAS

% L

and

Co

ver

0

20

40

60

80

100

0

20

40

60

80

100

CECIL PLAINS

NANDI

0

20

40

60

80

100

Matrix Source Bt cotton

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Pampas

2009-10

DROUGHT

2010-11

FLOOD

2011-12

NORMAL

2012-13

FLOOD

2013-14

DROUGHT

0

20

40

60

80

100

0

20

40

60

80

100

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100

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Cecil Plains

Dec 6Jan 6

Jan19Feb 9

Feb 23

Mar 16

0

20

40

60

80

100

Dec 6

Flood

Feb 8

Feb 22

Mar 8

Mar 22

Apr 6

0

20

40

60

80

100

Dec 6

Dec20

Jan 3

Jan 17

Jan 31

Feb 14

Feb 280

20

40

60

80

100

Dec 5

Dec 19Jan 2

Jan 15

Flood

Feb 2

Feb 20Mar 6

0

20

40

60

80

100

Dec 2

Dec 16

Dec 30

Jan 13

Jan 27

Feb 10

Feb 240

20

40

60

80

100

Helicoverpa armigera Helicoverpa punctigera

% H

elic

overp

a e

ggs c

olle

cte

d f

rom

Bt cotton

Date - Trip

*

* No eggs found

Nandi

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Helicoverpa armigera

and H. punctigera

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Random Forest Models What is it?

Machine learning technique

Average of a large series of de-correlated regression trees

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Random Forest Models What are the features?

• Distribution free; • Large # of predictors of diff. types (continuous and

categorical); • Handles missing data; • Handles collinearity – (i.e. landscape compositional data;

nested spatial scales) • Non-parametric modelling approach

4 spatial scales, 26 land uses, +temporal variables = 100+

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Top Predictors

from RF model –

Pruned Regression Tree

LARGEST

# predicted Ha eggs

(165) Yr 2;

>4.5 Hp eggs;

Sorghum @ 2km

< 15%

SMALLEST

# predicted Ha

eggs (3-6);

Cotdev pre-flwr

n=258

years (n=682)

LARGEST

# predicted Ha eggs

YR1,4,5; Lndscp B,C

Little fallow;

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Top Predictors

from RF model –

Pruned Regression Tree

TEMPORAL variables

Flowering Cotton,

Moon Phase,

Year,

& est. # Ha eggs

n=682

LARGEST

# predicted Hp eggs;

Waxing moon @ >80%,

or Cot flrw & lots of Ha

eggs;

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Random Forests Parametric models

Exploratory tool

- 100+ predictors

- Eg. 4 spatial scales, 3 temporal scales, egg

densities of each Helicoverpa spp, and 26

landuses;

confidence; shift question

-predictors affecting spp proportions & predict

abundance

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What predicts H. armigera egg abundance in cotton?

GLMM – fixed effects [Yr,Trip, unique field, season:lndscp random effects]

H. armigera

Eg

g d

en

sity

0 100

% Bt Cotton (km) % Bt Cotton @ 2 km

Landscape

N

CP

P E

gg d

ensity in c

ott

on

0 100

(adjusted R2 = 52.1 )

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• 20 x more eggs (1km radius) in

sorghum ‘surrounded’ by cotton, than

sorghum in a ‘sea’ of sorghum

•More moths too.

H. armigera eggs and moths in sorghum?

Early descriptive results

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What predicts H. punctigera egg abundance in cotton?

GLMM – fixed effects [Yr,Trip, unique field, season:lndscp random effects]

H. punctigera

Eg

g d

en

sity

0 100

% Bt Cotton (km)

Cotton

development

% of Full Moon % fallow (bare soil) @ 1km

No.

of

eggs in c

ott

on

(adjusted R2 = 47.9)

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Summary of Results:

Spatial drivers dominate for H. armigera

Temporal drivers dominate for H. punctigera

Local landscape

Host preference (sorghum over cotton)

80% waxing to full moon

Cotton Development (squares to open flowers)

No crops at 1km

‘Influence of the moon is likely to be

complex’ Zalucki 91; Zalucki et al 94; Morton et al. 81;

Walker 89; Scholz & Parker 2003;

Understanding of key drivers of global pests

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Presentation title | Presenter name | Page 63

Summary Ex. ‘2’:

? IMPACT

(Resistance Management

Plan)

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Future opportunities to reduce farm inputs:

N

Bommarco et al, Oecologia (in review) Lundin et al 2013, Proc Royal Soc B

YIELD

Termite and Ant Tunnels – No-till marginal grain systems

Evans et al, 2012, Nature Communications

H2O infiltration; N uptake;

YIELD 37%

Ecological intensification

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• Movement • Landscapes • Farming practices

Conclusion:

Impact • Capture of pest control services from

landscape mosaic = protect natural farm assets • Potential to refine resistance management

plan = reduce food fibre loss; reduce pesticide use

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Presentation title | Presenter name | Page 66

15-20-fold

increase in the

amount of

pesticides used

worldwide in

grain

(Oerke 2006)

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Thank you CSIRO Dr Nancy Schellhorn

T +61 7 3833 5710

e [email protected] w http://www.csiro.au/people/Nancy.Schellhorn

AGRICULTURE FLAGSHIP

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Egg Fates

H. armigera

H. punctigera

Unable to distinguish

Unviable

Parasitized (spp)

Unable to distinguish

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Presentation title | Presenter name | Page 72

Doubling of Grain Production since 1960’s (Oerke, 2006, J Ag Sc)

6.9-fold increase in N fertilizion

1.7-fold increase in amount of irrigated cropland

1.1-fold increase in land in cultivation

0.5-0.6 increase in genetic improvements by crop breeders (McLaren 2000)

15-20-fold increase in the amount of pesticides used worldwide

(No significant decrease in crops losses; has enabled farmers to

increase crop productivity without losing an economically non-acceptable

portion of their crop to pests)