Use of Phenology Models for Insect Management in

Southeastern Tree Fruits

Jim WalgenbachDepartment of Entomology

NC State UniversityMHCREC, Mills River, NC

Raleigh

Mills River

Charlotte

Direct Insect Pests of Apples and Peaches in NC

• San Jose Scale• Plum Curculio• Stink Bugs• Oriental Fruit Moth• Tufted Apple Bud Moth• Codling Moth• Comstock Mealybug• Apple Maggot

Attributes of Insect Phenology Models in Tree Fruits

• Temperature-driven

• Models predict biological events important in management– Adult emergence, egg hatch, etc.

• Predominately used to optimize– Insecticide use– Scouting resources

Factors Contributing to Use of Phenology Models by Grower

Community

• Host range and mobility of pest

• Common vs. sporadic pest

• Consequences of over-spraying– Cost, resistance development

• Availability, efficiency and ease of monitoring tools

• Simplicity of outputs

Direct Insect Pests of Apples and Peaches in NC

• San Jose Scale• Plum Curculio• Stink Bugs• Oriental Fruit Moth• Tufted Apple Bud Moth• Codling Moth• Comstock Mealybug• Apple Maggot

Tufted Apple Bud Moth (Playnota idaeusalis)

0

25

50

75

100

125

150

0 30.5 61 91.5 122 152.5 183 213.5

Mo

ths

pe

r tr

ap APR MAY JUN JUL AUG SEP OCT

2nd Generation

Moths/trap % Egg hatch

0

25

50

75

100

% C

umulative egg hatch

TABM Pheromone Trap Catches and % Cumulative Egg Hatch

APR MAY JUN JUL AUG SEP OCT

0

25

50

75

100

125

150

Mot

hs/t

rap

0 1000 2000 3000 4000DD

Biofix

Codling Moth (Cydia pomonella)

0

5

10

15

20

0 30.5 61 91.5 122 152.5 183

Mo

ths

pe

r tr

ap

APR MAY JUN JUL AUG SEP

Codling Moth Degree-Day Model

• Riedl et al. 1976. Can. Entomol.• Predicts percentage of adult emergence and egg

hatch of first and second generations.• Degree-day accumulations begin at biofix,

defined as first emergence of male moth.• In practice, first sustained capture of male moth

in pheromone trap is biofix.• Insecticide applications are recommended at

initial egg hatch.

Codling Moth Phenology

Biofix

250DD

350DD

0

10

20

30

40

Mo

ths

per

tra

p

0

20

40

60

80

100

Adults Predicted Egg Hatch

APR MAY JUN JUL AUG SEP

1250DD

1350DD

Impact of Resistance Development on Phenological

Models

Developmental Rate of Insecticide-Resistant Codling Moth Populations is Slower than

Susceptible Populations

• E. Lue. 2005. Trade-offs between insecticide resistance and development time in codling moth. http://socrates.berkeley.edu/~es196/projects/2005final/Lue.pdf– Development from egg-adult was 10% greater for a Guthion-resistant

resistant compared to a susceptible codling moth population

• Boivin, T., J. Chadoeuf, J.C. Bouvier, D. Beslay, and B. Saupanor. 2005. Modeling the interaction between phenology and insecticide resistance genes in the codling moth, Cydia pomonella. Pest Manag. Sci. 61: 53-67.– Pheromone trapping studies validated a model that predicted delayed

emergence of insecticide resistant codling moth, and segregation of susceptible and resistant individuals increased with the frequency of resistance.

0

10

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30

0 200 400 600 800 1000

Per

cen

tag

e C

atch

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30

0 200 400 600 800 1000

Per

cen

tag

e C

atch

0

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20

30

0 200 400 600 800 1000

Per

cen

tag

e C

atch

0

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0 200 400 600 800 1000

Pe

rce

nta

ge

Ca

tch

2007 First Generation Trap Captures vs. Degree-Days Accumulations

MHCRS Orchard H1

Orchard L1 Orchard P1

OP-Susceptible Orchards OP-Resistant Orchards

Predicted vs Actual Percentage Catch of 1st Generation Codling Moth

0

20

40

60

80

100

0 200 400 600 800 1000 1200

DD from biofix

% A

du

lt C

ap

ture

ModelOrchard L1MHCRS

0

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60

80

100

0 200 400 600 800 1000 1200

DD from biofix

% A

du

lt C

ap

ture

ModelOrchard H1Orchard P1

Mean deviation (d) from model

Orchard L1 -10.6 (±6.3) MHCRS + 4.8 (±3.3)

Mean deviation (d) from model

Orchard H1 + 27.7 (±5.4) Orchard P1 + 19.2 (±1.9)

0

20

40

60

80

100

0 200 400 600 800 1000

DD from biofix

Mo

ths

pe

r tr

ap

2006 First Generation Codling Moth Pheromone Trap Captures – Orchard H1

May June

-2 -1.5 -1 -0.5 0 0.5 1

Dose (log ppm)

% M

orta

lity

(p

rob

it s

cale

)

Lab Orchard H1

5

10

20

30

40506070

80

90

95

Dose-Response of Codling MothPopulations to Azinphosmethyl

May June

0.41 0.77

Codling Moth Phenology - 2009

Biofix

250DD

350DD

0

10

20

30

40

Mo

ths

per

tra

p

0

20

40

60

80

100

Adults Predicted Egg Hatch

APR MAY JUN JUL AUG SEP

Percen

tage eg

g h

atch

1250 DD

Predicted vs. Actual Emergence of Codling Moth Based on DD Accumulations - 2009

0

20

40

60

80

100

% C

um

ula

tive

mo

ths

Predicted Actual

APR MAY JUN JUL AUG SEP

410DD

In-Orchard Monitoring and Information Delivery