James A. BethkeJames A. BethkeFloriculture Farm Advisor, UCCE San DiegoFloriculture Farm Advisor, UCCE San Diego

County CaliforniaCounty California

INSECTICIDE INSECTICIDE RESISTANCE RESISTANCE

MANAGEMENT AND MANAGEMENT AND ROTATIONROTATION

Presentation OutlinePresentation Outline• How does pesticide resistance occur?How does pesticide resistance occur?

•• Classic thought Classic thought•• Examples from experienceExamples from experience

One GrowerOne Grower’’s bane - Leafminerss bane - LeafminersDow - Western Flower ThripsDow - Western Flower Thrips

Why rotate? Why rotate?IRAC MOA - Modes of ActionIRAC MOA - Modes of Action

•• Solutions Solutions•• Resources Resources

How does pesticide resistance occur?How does pesticide resistance occur?Classic resistance causeClassic resistance cause

•• It It’’s all in the genetics.s all in the genetics.•• ‘a heritable change in the sensitivity of a pest population

that is reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for that pest species’.

Think another wayThink another wayItIt’’s in how much you apply and s in how much you apply and how often you use the same products (cost?).how often you use the same products (cost?).

Liriomyza trifolii the serpentine leafminer

Liriomyza trifolii third instar on mums

Liriomyza trifolii infestation on gerbera

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UCR 1 RR=1

UCR 1 No Conserve use

SB 1 Occassional use of Conserve/year

SB 2 264oz of Conserve/year

SB 3 20oz of Conserve/year

SB 4 352oz of Conserve/year

Orange and San Diego >1100oz/year

LC50

SB 1RR=25

SB 3RR=108

SB 2RR=25

SB 4RR=406

4000 ppm1ppm 10ppm 100ppm

194ppm

Orange &San DiegoRR=>667

1000ppm

Heavy infestations ofHeavy infestations ofresistant leafminersresistant leafminers

Mum grower - leafminers were >1000fold resistant to spinosad

Gerbera grower - leafminers were >667fold resistant to spinosad

Heavy infestations ofHeavy infestations ofresistant leafminersresistant leafminers

One year later both populations were assayed again.

Unfortunately, there was no change in the level of resistance for either population.

However, one grower changed and theother did not.

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UCR 1 RR=1

G 2 RR=24

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UCR 1 No Conserve use

G 1 100-120oz of Conserve/year

G 2 440oz of Conserve/year

LC50

1ppm 100ppm10ppm

35 ppm

Recent AssaysRecent AssaysThrips assays 24 hour mortalitySource Conserve Rate Live Dead % Mortality

UTC 74 5 6.3GROWER#1 50 45 45 50.0Limonium 200 13 56 81.2

UTC 52 11 17.5GROWER#2 50 0 88 100.0Butterfly 200 0 71 100.0

UTC 96 22 18.6GROWER#3 50 33 48 59.3

200 5 62 92.5

UTC 49 12 19.7GROWER#4 50 5 74 93.7Butterfly 200 0 49 100.0

Silverleaf Whitefly

Q Biotype ResistanceQ Biotype ResistanceFirst cases of First cases of

resistance to the resistance to the Neonicotinoid Neonicotinoid

InsecticidesInsecticides

View this slide at the IRAC web site: IRAC-online.org

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Control Clothianidin Imidacloprid Dinotefuran Thiamethoxam

Days Post Treatment 12

Efficacy of Neonicotinoids Against Adult Whiteflies after a 48 Hour Exposure

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Efficacy Against Efficacy Against ‘‘QQ’’•• Trials run on Q-Biotype from a commercial source Trials run on Q-Biotype from a commercial source challenged by insecticideschallenged by insecticides

•• Effective active ingredients against the Q-Biotype to Effective active ingredients against the Q-Biotype todate are the following:date are the following:

•• Dinotefuran (+Adults, Thiamethoxam?)Dinotefuran (+Adults, Thiamethoxam?)

•• Avid Avid

•• Avid+ Avid+Talsar Talsar (+Adults)(+Adults)

•• PyridabenPyridaben

•• Spiromesifen Spiromesifen

Pylon

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334.4 167.2 83.6 41.8 20.9

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Floramite

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Avid

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21.96 10.98 5.49 2.74 1.37

PPM AI and rate factor of the highest recommended labeled rate

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Akari

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377.6 188.8 94.4 47.2 23.6

PPM AI and rate factor of the highest recommended labeled rate

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Early Rotation Early Rotation SchemesSchemes

CHEMICAL CLASS• Organochlorines (endosulfan)

• Carbamates (carbaryl)

• Organophosphates (chlorpyrifos)

• Pyrethriods (permethrin)

• Nicotinoids (imidacloprid)

• IGRs (cyromazine)

• Macrocyclic lactones (abamectin)

• Oils/Soaps

NERVOUS SYSTEM

Nerve cell Synapse

Axon

DendritesSignal transmission

ACh and AChE

Receptors

NA+ and CL- channels

Modes of ActionModes of Action

MODE OF ACTION• Nervous system

• Chloride (CL-) channel blocker

• Mimic or block neurotransmitter (ACh)

• Act on the sodium (NA+) channel

• Block AChE

• Suffocation

• Desiccation

MODE OF ACTION• METI - Mitochondrial respiration

• Lipid synthesis inhibitor

• Insect growth regulators

• Chitin synthesis inhibitors

• Juvenile hormone mimics

Unknowns

NERVOUS SYSTEM

Synapse

Axon

NERVOUS SYSTEM

Synapse

Axon

MFOs and Esterases

Basics of RotationBasics of Rotation

Mites

MOA Group

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A rotation for mites.

1. Save best for toughtimes (Avid, Judo)

2. During cool fall andwinter, use softerproducts (Soaps, oils,Hexygon, Tetrasan).

3. During the warmerseason, when there aremore mitegenerations, ratherthan increase thefrequency, rotateamong IRAC MOA.

MOA Group

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Never use Avid or Judo,Kontos unlessnecessary.

Begin with one productsuch as Floramite.One week later,switch to Shuttle,then to Akari. Watchthe label and followIPMrecommendations

As temperatures rise andpopulations increase,tank mix productsthat kill mobilestages with those thatkill eggs such as:

Floramite plus Hexygon

Or plus TetraSan

OBSERVATIONSSuccessful growers monitor their crop veryclosely and treat hot spots. The products

they use are highly effective.

Growers that are less successful are treatingon a scheduled basis and usually tank mixing

more than one chemical class at one time.

ConclusionsConclusionsResistance Avoidance Resistance Avoidance vs vs Resistance ManagementResistance Management

Very effective new productsVery effective new products

More to comeMore to come

tetronic tetronic acid lipid synthesis acid lipid synthesis inhibitorsinhibitors

numbered compoundsnumbered compounds

METIMETI

Many companies going with softer chemicalsMany companies going with softer chemicals

Avoiding Pesticide Resistance• Scouting

• Early detection

• Proper identification of the pest

• Minimize frequency of application

• Avoid tank mixes

• Rotate the mode of action

• Use a more integrated approach

Don’t be confused!

Don’t be confused betweenresistance and poor coverage or

inability to contact the pest.

Where you find themWhere you find them is where you treatis where you treat

• Aphids - terminals and undersides of leavesAphids - terminals and undersides of leaves•• Leafminers - within leaf mines, adults all Leafminers - within leaf mines, adults all•• Whiteflies - all stages undersides of leaves Whiteflies - all stages undersides of leaves•• Thrips - in tight spaces, buds and flowers Thrips - in tight spaces, buds and flowers•• Mites - undersides of leavesMites - undersides of leaves•• Mealybugs - in crevasses or tight spacesMealybugs - in crevasses or tight spaces and covered in waxy coatingand covered in waxy coating

ResourcesResourcesUCCE Web siteUCCE Web site

http://www.ipm.ucdavis.edu/PMG/

ResourcesResources

ResourcesResourcesIRAC - Insecticide Resistance Action CommitteeIRAC-online.org

ResourcesResourcesSyngenta and OHP have Chemical Class Chartswww.ohp.com/Labels_MSDS/PDF/CCC_XI.pdf