soybean aphid wisconsin 2003 recap latitude bridge illinois – iowa – minnesota - wisconsin...

Soybean Aphid Wisconsin 2003 Recap

Latitude Bridge

Illinois – Iowa – Minnesota - Wisconsin

February 5th, 2004

Eileen CullenUniversity of Wisconsin Extension

Entomology Department

Wisconsin Recap 2003

State Soybean Aphid Survey

Dynamic Threshold Concept

Role of Insecticides

Treatment Decision Dynamics

Additional (Evolving) Tactics

Eileen Cullen – UW Extension, Entomology

Summary 19% of sites with 201-500 aphids/plant

20% of sites with 501-1000 aphids/plant

16% of sites with 1001-2000 aphids/plant

11% of sites with 2000+ aphids/plant

Courtesy of Krista Lambrecht, WI DATCP

Statewide Statewide AverageAverage

770 770

aphids/plantaphids/plant

5665669393

633633

170170

149149

680680

10061006

12681268

Northwest

West Central

Northeast

Southwest

Southeast

994994

East Central

South Centra

l

Central

North Central

District District AveragesAverages

Number of Soybean Aphids per Plant

Courtesy of Krista Lambrecht, WI DATCP

Direct and Indirect Effects on Yield

Reduced# flowers

Reduces# beansper pod

Reducesbean size

Changes beanquality

Virus Transmission

Soybean aphids feed on plant sap Photo © Iowa State University

Soybean Aphid Threshold

Potassium Levels

Drought Stress!Soybean Varietal Tolerance to SBA?

Indirect Yield Loss

Direct Yield Loss

Crop Stage Soybean Yield Responseto Insecticide Treatment

Biological Control& Abiotic Factors

Economic Injury Level = Pest density which causes loss equal to the cost of control.

Economic Threshold = Pest density at which control action is taken to PREVENT pest population from reaching or exceeding the EIL

Cost of Control

Expected price of crop

Soybean aphid Exponential Growth


-0.5

1.5

3.5

5.5

7.5

9.5

11.5

13.5

15.5

17.5

22-Jul 27-Jul 1-Aug 6-Aug 11-AugSpray Date

Yield Diff erence

Bu/A

Yield Diff (Bu/ A)

Yield Response by Spray Date

31 on-farm strip trials from WI 2003 July 23 – August 11 ApplicationsAvg. Yield Advantage = 7.1 Bu/A


TradeName

Active Ingredien

t

Rate/Acre

(fl. oz.)

REI

(Hours)

PHI

(Days)

Asana* esfenvalerate

5.8 to 9.6 12 21

Baythroid** cyfluthrin 2.8 fl. oz. 12 45 (15 green forage)

Mustang Max

zeta-cypermethr

in

2.8 to 4.0 12 21

Warrior lambda- cyhalothrin

1.92 to 3.2 24 45

Pounce* permethrin 4.0 to 8.0 12 60

* 2(ee) Label** Labeled for soybean aphid Suppression

Pyrethroid Labels for Soybean Aphid


TradeName

Active Ingredient

Rate/Acre

(pint/A)

REI PHI

(Days)

Dimate 4EC*

Dimethoate 4E*

dimethoate ½ to ¾ 48 hrs 21

Lorsban 4E chlorpyrifos 1 to 2 24 hrs 28

Penncap-M methyl-parathion

1 to 3 4 days*

5 days**

20

Organophosphate Labels for Soybean Aphid

* 2(ee) Label *avg. annual rainfall = or > than 25”** avg. annual rainfall < 25”


TradeName

Active Ingredient

Rate/Acre

(pint/A)

REI PHI

(Days)

Furadan 4F carbofuran ¼ to ½ 48 21

Carbamate Label for Soybean Aphid


Product Performance & Canopy Distribution

Lorsban

Furadan

Pyrethroids

Volatile distribution through canopy.May “fume” into untreated check strips

Systemic, a.i. activity within plantin addition to contact activity

Cannot work its way through canopy beyond contact activity.

Coverage in closed canopy critical for efficacy against aphids at lower and inner locations on plant.


Product Performance & Temperature

Lorsban

Furadan

Pyrethroids

Optimal performance at higher temps.(may increase “fuming” action)

Also relatively better at higher temp

Exhibits a Negative Temp Relationship:Works better under cool conditionsbelow 90oF.


Product Performance & Residual

Lorsban

Furadan

Pyrethroids

Short residual, measured in days.

Longer residual than organophosphates.Some additional feeding exposure,due to systemic activity

Longest residual , 2 weeks or more


Data Courtesy of Craig Grau, UW Plant Pathology

Watch Late-Planted FieldsPlants relatively younger, more nitrogen (?)Soybeans in critical bloom/reproductive stages at aphid build

0

100

200

300

400

Sampling Date

Aphids on Youngest Trifoliate 9-May

29-May7-Jun

Relatively Cool Summer 2003

Optimal temperature for soybeanaphid development: 68 to 77 °F

Soybean aphid predators function better at high temperatures

Fungal disease: prolonged hot and humid conditions


Biological Control

Weather

Biotic and Abiotic Dynamics!

Drought, Scattered Rainfall Heavy rainfall can temporarily reduceaphid populations – depending on canopy density.

Natural Enemy “Lag” TimeNatural Enemy “Lag” Time Spray Timing Critical – Aphid Resurgence Spray Timing Critical – Aphid Resurgence

FactorFactor

0

200

400

600

800

1000

1200

1400

1600

7/11 7/18 7/25 8/1 8/8 8/17 8/24 8/29 9/5

mea

n s

oybe

an a

phid

s pe

r pl

ant

0

20

40

60

80

100

nat

ura

l en

emie

s /

80

sw

eeps

soybean aphidHarmoniaOrius

LacewingNabis

Bob Ellingson and David Hogg, UW Entomology

Winged Aphids Efficient Virus Vectors

Alfalfa Mosaic Virus

Soybean Mosaic Virus

Cucumber Mosaic Virus Snap Beans

Foliar symptoms of virusYellow chlorotic leaf patterns

Crinkled, “drawstring” leaflets

No Thresholds for VirusEileen Cullen – UW Extension, Entomology

Photo Courtesy of Lisa BehnkenU of MN, Extension

Soybean Aphid – Interaction with other Stresses

Drought Stress

Potassium Deficiency

Multiple Pest complex -Bean Leaf Beetle -BLB transmitted virus BPMV -Planting Dates: late plant against BLB/BPMV early plant less aphid trouble


Aphid Colonization of Different Soybean Lines

0

200

400

600

800

1000

1200

1400

1600

1800

2000

6/20 6/30 7/9 7/15 7/21 7/28 8/4 8/11 8/19 8/25

153.282Spansoy250BSR10190573AR16M94-209136

Craig Grau et al.– UW Extension, Plant Pathology

Soybean GeneticsBreeding lines differ for population density and symptom severity

Effects of Soybean Aphid on Yield

42

21

3032

57

44

27

21

34

24

33 34

0

10

20

30

40

50

60

AR16 90573 BSR101 153.282 Span250 M94-209136

Soybean Lines

YieldBu/a

Insecticide spray

No spray

Craig Grau et al.– UW Extension, Plant Pathology

Soybean GeneticsYield Response to Insecticide – Breeding Line Differences

Role of Insecticides:Insecticides timed properly on the basis of scoutingReduce aphid populations and plant stress quickly

ScoutingThreshold

Optimal Timing

Evolving Approaches and Correlations:

Varietal Resistance/ToleranceBiological Control

Nicotinoid Insecticide Seed TreatmentMoisture StressPotassium Level


Soybean Aphid Efficacy Data

& Threshold Guidelines

Latitude Bridge

Illinois – Iowa – Minnesota - Wisconsin

February 5th, 2004

Eileen CullenUniversity of Wisconsin Extension

Entomology Department

Efficacy Data & Management Guidelines


Nicotinoid Seed Applied Insecticides on Soybean

WI 2003 Efficacy Data:

Foliar Residual ActivitySeed Treatments

2004 Scouting &ThresholdGuidelines

a.i. ~ clothianidin [Poncho]

a.i. ~ imidacloprid [Gaucho]

a.i. ~ thiamethoxam [Cruiser]

Systemic. As the seed imbibes water and germinates, a.i. on the seed is taken up into plant through the xylem.

Nicotinoid Insecticide Seed TreatmentHow does it work in the plant?

Graphic courtesy of Karen Arthur, Gustafson LLC

Nicotinoid Class:


Sodium Channel:Pyrethroids

Acetylcholine esterase:OP’s, Carbamates

Acetylcholine receptor:Neonicotinoids

Pre-synapse

Post-synapse

Synaptic Cleft

Nicotinoid Insecticide Seed TreatmentHow does it work in the insect?

Graphic courtesy of Karen Arthur, Gustafson LLC

Nicotinoid Seed Treatment

Soybean – In Trial Phase


Soybeans treated on a grams a.i. per 100 Kg seed basis. “Poncho 62.5” = 62.5 g a.i. / 100 Kg seed

Early season protection. Interest in how long into season activity persists.

(4 – 6+ weeks depending on a.i., crop, and pest)

Nicotinoid Resistance ConcernsImidacloprid – clothianidin - thiamethoxam

Selective activity against piercing-sucking insect feeding and virus transmission.

Reduced non-target effects

Field Corn corn rootworm Field Corn 2° soil pests YieldGard Rootworm Bt Field Corn seed protectant

Seed and Food Grade Soybeans Grain Soybeans (registration in development phase)


Soybean Aphid Insecticide Trials

Arlington, WI 2003

Foliar Trial (pyrethroids ,organophospates)

Nicotinoid Seed Treatment Trials ~ clothianidin [Poncho] ~ imidacloprid [Gaucho] ~ thiamethoxam [Cruiser]


Soybean aphid FOLIAR trial. Arlington, WIMean Aphids/Plant 4d, 1wk and 2 wks post treat.

Treated 7/31 at R2 (500+ aphids/plant)

Mean yields (bu/A) within a column followed by a different letter are significantly different at = 0.05 (Fishers exact test)

Treatment 4 days 1 week

2 weeks

Untreated 996.5 a 1518.8 a 1823.5 a

Warrior 1CS 3.84 oz. 26.3 f 22.2 e 72.6 e

dimethoate 1 pt. 36.2 e 45.5 d 147.0 c

Baythroid 2.8 oz. 181.5 d 344.5 b 476.0 b

Mustang Max 4.0 oz. 203.2 d 200.3 c 307.8 c

Mustang Max + NIS 353.9 b 437.1 b 440.6 b

Asana 6.4 oz. 330.4 b 346.5 b 349.3 b

Asana 9.6 oz. 204.6 c 368.3 b 168.9 c

Lorsban 4E 2.0 pt. 0.5 g 15.3 e 91.9 d


Seed Treatment TrialSoybean Aphid

Trial 1Planted: June 9Harvest: Oct 16Cultivar: NK S19-V2

Plots: 10’ w x 25’ lCRBD: 4 replicates

Poncho 62.5Poncho 125Gaucho 62.5Cruiser 62.5CHECK

Trial 2Planted: June 9Harvest: Oct 16Cultivar: NK S24-K4

Plots: 10’ x 25’ lCRBD: 4 replicates

Cruiser 30Cruiser 50Gaucho 62.5CHECK


0

500

1000

1500

2000

2500

3000

3500

8-Jul 16-Jul 22-Jul 30-Jul 4-Aug 13-Aug

Untreated

Poncho 62.5

Poncho 125

Gaucho

Cruiser

Soybean Aphid Seed Treatment Trial 1, Arlington WI 2003

Mean Aphids/Plant by sampling date

Aphids/plant

Sample Date

62.5

62.5

250 Aphids/Plant


Treatment Yield (bu/A)

Untreated 38.1 bPoncho 62.5 42.2 abPoncho 125 44.3 abGaucho 62.5 43.2 abCruiser 62.5 52.8 a

Soybean [aphid] seed treatment trial 1, Arlington WI 2003 Yield (bu/A) by Treatment. (P = 0.1151; F = 2.33; df, 4)

Means followed a different letter are significantly different at = 0.05


0

500

1000

1500

2000

2500

8-Jul 16-Jul 22-Jul 30-Jul 4-Aug 13-Aug

Untreated

Cruiser 30

Cruiser 50

Gaucho

Soybean Aphid Seed Treatment Trial 2, Arlington WI 2003

Mean Aphids/Plant by sampling date

Aphids/plant

Sample Date

62.5

250Aphids/Plant


Treatment Yield (bu/A)

Untreated 38.1 c

Cruiser 30 43.6 bc

Cruiser 50 49.7 ab

Gaucho 62.5 41.3 bc

Soybean [aphid] seed treatment trial 2, Arlington WI 2003Yield (bu/A) by Treatment. (P = 0.002; F = 6.59; df, 5)

Means followed a different letter are significantly different at = 0.05


Seed Treatment Summary

Seed treatment trials were LATE planted (June 9).

Seed treatment for soybean aphid will need to take planting date into account to ensure systemic activity during aphid impact.


EPA Section 18 Emergency Exemption Registration in WI and IA (March 28 to June 1, 2003) for Gaucho on seed and food grade soybean only. Labeled for early season Bean Leaf Beetle and Bean Pod Mottle Virus control.

Gustafson has been contacted by the state of IA with plans to request another Section 18 for Gaucho seed treatment 2004. Early season Bean Leaf Beetle control and Soybean Aphid. May cover all soybeans.

Soybeans are treated by the manufacturer or seed dealer, NOT on-farm by producer. Soybeans may only be treated in state(s) with the Section 18 registration.

[2003: 400,000 Acres worth of seed/food-grade beans could be treated in IA and WI, then planted in other states].


CooperatingEntomologists/

Universities

Ragsdale,Ostlie, et al.

U of Minn

Eileen CullenU of WI

Phil GlogozaND State

ChrisDiFonzo

MSU

Hammond,EisleyOSU

Doug Johnson

Univ of Kentucky

Marlin RiceIowa StateTom Hunt

Univ of Nebraska

Tracey

Baute

OMAF

VoegtlinSteffeyGray

U of IL

LarryBledsoePurdue

Wayne Bailey

U of MO

Consensus Recommendations for 2004

Chris DiFonzo, Michigan State University

Threshold

- 250 aphids per plant250 aphids per plant

- assumes aphid numbers are on the increaseincrease

- provides a 7-day lead time (call in equipment, deal with weather delays)

- use through R4 (full-pod stage)

Cannot overemphasizeDROUGHT


How fast can a soybean aphid reproduce?

[data generated in the lab by Ragsdale et al., Univ. of Minnesota]

TempTemp68oF

77oF

86oF

95oF

LifeLifespan span (days)(days)

22

15

12

3 (die)

DoublingDoublingtime time (days)(days)

2

1.5

2

dead

TotalTotal# #

babiesbabies75

73

23

0

FirstFirstbabiesbabies

(# days)(# days) 7

5

5

--Chris DiFonzo, Michigan State University

[Based on data from University of Minnesota plots in 2003]

PricePrice$/bu$/bu

$5.00

$6.00

$7.00

How much yield (# bushels) must be lost from aphid damage

to equal a control cost of $12.00/ acre?

##bubu2.4

2.0

1.7

60604.0%

3.3%

2.8%

50504.8%

4.0%

3.4%

40406.0%

5.0%

4.2%

% of Yield potential, bu/acre% of Yield potential, bu/acre


How many aphids per plant cause that much yield loss…..

++ a 7-day lead time? a 7-day lead time?

254

210 254

305

178 216

381

270

317

[Based on data from University of Minnesota plots in 2003]

PricePrice$/bu$/bu

$5.00

$6.00

$7.00

60604.0%

3.3%

2.8%

50504.8%

4.0%

3.4%

40406.0%

5.0%

4.2%

% of Yield potential, bu/acre% of Yield potential, bu/acre##bubu2.4

2.0

1.7


ScoutingWhen:When: begin late June/ early July (may vary by region)

What:What: Whole plant counts- 20 to 30 plants per field - no apparent edge effects (winged aphids colonize uniformly)- increasing populations even out across plants

Pay special attention to:Pay special attention to: - areas w/ buckthorn (colonized early)- late-planted fields - double-cropped beans- beans under stress, particularly DROUGHT STRESS

How many times?How many times? Fields have to be visited multiple times

How Long?How Long? 2003, up to third week of August in many locations.Chris DiFonzo, Michigan State University

Timing ofApplication

R1 – R2bloom

R8 mature

R7matur-

ing

R6full

seed

R5seeds

forming’filling

R3-R4pods

forming,growing

Do Nottreat

Late Vegstages

250 aphids per plant

- Increasethreshold.

- Yield benefitmay be less.


Continue to scout and work from 250/plantas a reference threshold

Prepare with Guidelines Presented Here:

ScoutingUse of Threshold

Optimal Spray Timing

Will 2004 be a repeat of 2003?

What is the Soybean Aphid “Norm”?

Watch for state-specificinformation in your summer newsletters.

Wisconsin Crop Manager:

http://ipcm.wisc.edu/wcm/




soybean aphid wisconsin 2003 recap latitude bridge illinois – iowa – minnesota - wisconsin...

Documents

entomology slide

soybean aphid wisconsin

bua eileen cullen uw

wi datcp slide

soybean varietal tolerance

yield advantage

wisconsin recap

economic threshold