Managing Pesticide Managing Pesticide Resistance on AvocadosResistance on Avocados

Eduardo Humeres, Joseph Morse, Alan Urena, Eduardo Humeres, Joseph Morse, Alan Urena, Lindsay Robinson, Pam Watkins, Paul Flores, Darren Lindsay Robinson, Pam Watkins, Paul Flores, Darren

AndersonAnderson

University of California Department of EntomologyUniversity of California Department of EntomologyRiverside, CARiverside, CA

PresentationPresentation

What is pest resistance?What is pest resistance? Key avocado pestsKey avocado pests Management of key avocado pestsManagement of key avocado pests Avocado pest resistanceAvocado pest resistance SummarySummary

Pest ResistancePest Resistance

The development of resistance The development of resistance to a pesticide is perceived in a to a pesticide is perceived in a number of ways (McKenzie, number of ways (McKenzie, 1996):1996):

• Farmers, horticulturists or Farmers, horticulturists or agricultural advisersagricultural advisers

• Recognize resistance as a decrease in Recognize resistance as a decrease in the effectiveness of control of a pest the effectiveness of control of a pest provided by a chemicalprovided by a chemical

• GeneticistGeneticist• Attempts to define the heritable basis of the Attempts to define the heritable basis of the resistance phenotyperesistance phenotype

• ToxicologistToxicologist• Observes the change from susceptible to Observes the change from susceptible to resistance as a shift in dosage-mortality resistance as a shift in dosage-mortality lineslines

Early in resistance Early in resistance evolutionevolution

A B

Concentration

Pro

port

ion o

f p

op

ula

tion

Resistant Resistant individuals at low individuals at low numbersnumbers

FitnesFitnesss

SeleçãoSeleção

Concentration

A BPro

port

ion o

f p

op

ula

tion

SelectionSelection(= pesticides (= pesticides

sprays)sprays)

Concentration

A B

Distribution Distribution after after

resistance resistance has evolvedhas evolved

Pro

port

ion o

f p

op

ula

tion

Key Avocado Key Avocado PestsPests

Scirtothrips perseae Scirtothrips perseae (Thysanoptera: (Thysanoptera: Thripidae)Thripidae)

Avocado Avocado ThripsThrips

Bio

log

yB

iolo

gy

(Hoddle & Morse 2004)

Avocado Thrips: food Avocado Thrips: food sourcesource

Avocado Thrips Avocado Thrips DamageDamage

Avocado Fruit Avocado Fruit SetSet

Oligonychus perseaeOligonychus perseae (Acari: (Acari:

Tetranychidae)Tetranychidae)

Persea Persea MiteMite

Female

Male

(Hoddle, 1999)

Bio

log

yB

iolo

gy

Avocado Persea Mite Avocado Persea Mite DamageDamage

• Hass cultivar most damagedHass cultivar most damaged

• Mites occur mainly on the underside of the Mites occur mainly on the underside of the leaves along the midrib, main veins and leaf leaves along the midrib, main veins and leaf depressionsdepressions

• Lower epidermal, spongy parenchyma and Lower epidermal, spongy parenchyma and palisade cells of the leaf tissue are destroyed palisade cells of the leaf tissue are destroyed and large necrotic areas on the leaf result from and large necrotic areas on the leaf result from feedingfeeding

(Aponte & McMurty, 1997)(Aponte & McMurty, 1997)

Avocado Pests Avocado Pests

Fluctuations Fluctuations

JAN FEBMAR

APRMAY

JUN JUL AUG SEP OCTNOV

DEC

Persea MiteAvocado Thrips

Management of Management of Key Avocado Key Avocado

PestsPests

Context of Chemical Control Research Context of Chemical Control Research with Avocado Pestswith Avocado Pests

• Worldwide, few examples of complete biological Worldwide, few examples of complete biological

control of pestiferous thrips species (chemical control of pestiferous thrips species (chemical

intervention often required)intervention often required)

• Scirtothrips citriScirtothrips citri (Citrus thrips) (Citrus thrips)

• Scirtothrips aurantiiScirtothrips aurantii (South African citrus thrips) (South African citrus thrips)

• Scirtothrips dorsalisScirtothrips dorsalis (Chili or yellow tea thrips) (Chili or yellow tea thrips)

Avocado Thrips

• Considerable research has focused on control using Considerable research has focused on control using

augmentative releases of various predaceous mite speciesaugmentative releases of various predaceous mite species

• Released mites do not appear to persist from year to yearReleased mites do not appear to persist from year to year

• Generally, cost of effective annual augmentative releases is Generally, cost of effective annual augmentative releases is

considered prohibitive considered prohibitive

Avocado Persea Mite

• General observationGeneral observation – avocado thrips and – avocado thrips and

persea mite can build to economically injurious persea mite can build to economically injurious

levels quickly levels quickly under ideal conditionsunder ideal conditions

• Optimal weather conditions (cool coastal Optimal weather conditions (cool coastal

weather)weather)

• Presence of leaf, leaf flushes or young fruit Presence of leaf, leaf flushes or young fruit

(avocado monoculture = a banquet)(avocado monoculture = a banquet)

• Low endemic levels of biological control Low endemic levels of biological control

agentsagentsThus, an integrated approach is needed with key avocado pestsThus, an integrated approach is needed with key avocado pests

An Integrated Approach to An Integrated Approach to Avocado Pests Avocado Pests ManagementManagement

• Classical biological control - search in native range of Classical biological control - search in native range of avocado thrips and persea mite for effective natural avocado thrips and persea mite for effective natural enemies, import and release themenemies, import and release them

• Monitor field populations / natural enemies and apply Monitor field populations / natural enemies and apply selectiveselective treatments treatments only as neededonly as needed, based on , based on economic thresholds (potential for fruit damage)economic thresholds (potential for fruit damage)

• Monitor field populations for Monitor field populations for pesticide resistancepesticide resistance developmentdevelopment

• Continue to search for new selective chemical control Continue to search for new selective chemical control materials materials

Should I Spray for Avocado Pest Should I Spray for Avocado Pest Control?Control?

• Suggest growers might employ a Suggest growers might employ a knowledgeable pest control advisor to assist knowledgeable pest control advisor to assist in monitoring / spray decisionsin monitoring / spray decisions

• Monitor immature avocado thrips on young Monitor immature avocado thrips on young leaves, then move to fruit when the thrips leaves, then move to fruit when the thrips dodo

• Monitor for adult persea mite on mature Monitor for adult persea mite on mature leavesleaves

• Good treatment decisions are tricky - several Good treatment decisions are tricky - several factors are involved: factors are involved: • Tree size and health (vigor), grove topographyTree size and health (vigor), grove topography• Timing (leaf flushes), weatherTiming (leaf flushes), weather• Natural enemy levelsNatural enemy levels• Grower tolerance for fruit scarring (short-term Grower tolerance for fruit scarring (short-term

economics economics versus natural enemy and thrips versus natural enemy and thrips susceptibility susceptibility maintenance)maintenance)

• Leaf drop tolerance for persea mite feeding Leaf drop tolerance for persea mite feeding (increases (increases when > 7.5-10 % of the leaf when > 7.5-10 % of the leaf surface is damaged)surface is damaged)

• Spray equipment availabilitySpray equipment availability

• Many groves Many groves do notdo not require an avocado thrips require an avocado thrips or persea mite treatment in a particular yearor persea mite treatment in a particular year

Monitoring for Avocado Thrips in Monitoring for Avocado Thrips in SpringSpring

• Use a 10-14X hand or head lens to count Use a 10-14X hand or head lens to count the number of immature avocado thrips on the number of immature avocado thrips on the undersides of leaves prior to fruit setthe undersides of leaves prior to fruit set

• Study by Phillips and Faber on Hass Study by Phillips and Faber on Hass avocados in Ventura Coavocados in Ventura Co..

When 3-5 thrips are When 3-5 thrips are Resulting %Resulting %found per leaffound per leaf fruit fruit

scarringscarring

97 days before fruit set97 days before fruit set 26-38%26-38%

75-36 days before fruit set75-36 days before fruit set 18-28%18-28%

During fruit setDuring fruit set 6-15%6-15%

Monitoring for Avocado Thrips in Monitoring for Avocado Thrips in SpringSpring

• Avocado thrips do best under moderately cool Avocado thrips do best under moderately cool temperatures (68-76 °F)temperatures (68-76 °F)

• Under hot conditions (> 90 °F), populations Under hot conditions (> 90 °F), populations crashcrash

• Smaller fruit are more susceptible to damage Smaller fruit are more susceptible to damage by avocado thripsby avocado thrips

• As fruit become larger (1.5 inches or more in As fruit become larger (1.5 inches or more in diameter) - large numbers of thrips are needed diameter) - large numbers of thrips are needed to cause significant levels of fruit scarringto cause significant levels of fruit scarring

Monitoring for Avocado Thrips in Monitoring for Avocado Thrips in SpringSpring

Monitoring for Persea Monitoring for Persea MiteMite (Machlitt, 1998)

Number of persea mites per leaf =

Total no. of mites counted is divided by 10 (average no. mites per leaf) x 12 (correlation factor)

2004 Section 18 Allowing Agri-Mek Use2004 Section 18 Allowing Agri-Mek Use

• Agri-Mek available 1999-2004 under a Section Agri-Mek available 1999-2004 under a Section 18 Emergency Exemption for avocado thrips18 Emergency Exemption for avocado thrips

• 1999-2003: two applications per season allowed by 1999-2003: two applications per season allowed by air or groundair or ground

• Initial decision by EPA (Feb. 17) was to Initial decision by EPA (Feb. 17) was to denydeny the the 2004 (Year 6) Section 18 request due to the 2004 (Year 6) Section 18 request due to the availability of a registered alternative (Success availability of a registered alternative (Success registered in 2000)registered in 2000)

• Request submitted by CAC 9/03Request submitted by CAC 9/03

• Economic analysis 11/5/03Economic analysis 11/5/03

• Additional data 2/6/04Additional data 2/6/04

• Analysis of data from 23 UC field trials prepared Analysis of data from 23 UC field trials prepared 2/16/042/16/04

2004 Section 18 Allowing Agri-Mek 2004 Section 18 Allowing Agri-Mek UseUse

• Only last-minute CAC intervention and CA-Only last-minute CAC intervention and CA-DPR supporting a “Crisis Exemption” resulted DPR supporting a “Crisis Exemption” resulted in a compromise with EPA (Feb. 18, 2004)in a compromise with EPA (Feb. 18, 2004)

• A A singlesingle Agri-Mek application was allowed in 2004 Agri-Mek application was allowed in 2004 and and only by aironly by air

• Monthly conference calls (Guy Witney, Steve Monthly conference calls (Guy Witney, Steve Peirce, Joseph Morse) with Syngenta to make sure Peirce, Joseph Morse) with Syngenta to make sure full registration will be obtained for 2005 full registration will be obtained for 2005

• Appear on track for registration Feb., 2005 Appear on track for registration Feb., 2005

• We have not yet seen the draft Section 3 labelWe have not yet seen the draft Section 3 label

• Suspect will allow 2 applications per yearSuspect will allow 2 applications per year

• Unclear what filter strip requirements will beUnclear what filter strip requirements will be

2004 Section 18 Allowing Agri-Mek 2004 Section 18 Allowing Agri-Mek UseUse

Pesticides available for avocado Pesticides available for avocado thripsthrips

• ABAMECTINABAMECTIN - - Agri-Mek 0.15 ECAgri-Mek 0.15 EC

• SPINOSADSPINOSAD - Success 2 SC- Success 2 SC

- Entrust 80%- Entrust 80%

• SABADILLASABADILLA   - - Veratran D 0.2%Veratran D 0.2%

2004 Section 18 2004 Section 18 LanguageLanguage

• ABAMECTINABAMECTIN - - Agri-Mek 0.15 ECAgri-Mek 0.15 EC

• 10 - 20 fl oz / acre10 - 20 fl oz / acre

• Add 0.25 - 4 % NR-415 oil in 50 or more gpaAdd 0.25 - 4 % NR-415 oil in 50 or more gpa

• Single application per season; 12 h REI, 14 d PHISingle application per season; 12 h REI, 14 d PHI

• Application allowed only by airApplication allowed only by air

• See Section 3 label for 2005 restrictions and See Section 3 label for 2005 restrictions and reporting requirementsreporting requirements

• ABAMECTINABAMECTIN - - Agri-Mek 0.15 ECAgri-Mek 0.15 EC

• Agri-Mek relatively slow in killing avocado Agri-Mek relatively slow in killing avocado thripsthrips

• Quite persistent in leaves, with control Quite persistent in leaves, with control persisting 6-10 weeks or morepersisting 6-10 weeks or more

• Also effective in suppressing persea mite Also effective in suppressing persea mite populationspopulations

• pH of water should be 5-9, better above 6pH of water should be 5-9, better above 6

• SPINOSADSPINOSAD – Success 2 SC– Success 2 SC

• 4 - 10 fl oz / acre4 - 10 fl oz / acre

• Add 0.25% or more NR-415 oil by air or groundAdd 0.25% or more NR-415 oil by air or ground

• In order to delay thrips resistance development, do In order to delay thrips resistance development, do not apply Success more than 2 times per year; 4 h not apply Success more than 2 times per year; 4 h REI, 1 d PHIREI, 1 d PHI

• Do not apply more than 29 oz Success (0.45 lb Do not apply more than 29 oz Success (0.45 lb spinosad) per acre spinosad) per acre per cropper crop

10 oz + 10 oz + 8.8 oz = 0.45 lb ai10 oz + 10 oz + 8.8 oz = 0.45 lb ai

• 1.25-3 oz Entrust 80% + an organically 1.25-3 oz Entrust 80% + an organically approved oilapproved oil

(http://www.omri.org/OMRI_brand_name_list.htm(http://www.omri.org/OMRI_brand_name_list.html )l )

• SPINOSADSPINOSAD – Success 2 SC– Success 2 SC

• Similar chemistry as Agri-Mek (both are Similar chemistry as Agri-Mek (both are termed macrocyclic lactones and are termed macrocyclic lactones and are produced from Actinomycetes in produced from Actinomycetes in fermentation vats)fermentation vats)

• Efficacy against Lepidoptera but almost Efficacy against Lepidoptera but almost no mite no mite activityactivity

• More rapid kill of avocado thrips than Agri-Mek More rapid kill of avocado thrips than Agri-Mek but but less persistent in leavesless persistent in leaves

• Do not acidify the spray tank as with Veratran DDo not acidify the spray tank as with Veratran D

(ph 7-9 is optimal)(ph 7-9 is optimal)

Success Residual Activity with NR-415 Oil on Success Residual Activity with NR-415 Oil on Avocado Thrips, Field/Laboratory Bioassay; Bonsall, Avocado Thrips, Field/Laboratory Bioassay; Bonsall,

CA 1999CA 1999

0

20

40

60

80

100

1 7 14 21 29 35

Water controlSuccess 6 ozSucc + 0.25%Succ + 0.50%Succ + 1.0% Succ + 2.0%Succ + 4.0%

Co

rre

cte

d m

ort

alit

y (

%)

Age of residues (days)

• SABADILLASABADILLA – Veratran D– Veratran D

• 10-15 lb Veratran D 0.2% in 10-40 gpa by air 10-15 lb Veratran D 0.2% in 10-40 gpa by air or 20-100 gpa by ground; If 200 gpa is used, or 20-100 gpa by ground; If 200 gpa is used, increase to 20 lb per acre; 24 h REIincrease to 20 lb per acre; 24 h REI

• Botanical pesticide made from the ground seeds of Botanical pesticide made from the ground seeds of a lily-like plant from Venezuelaa lily-like plant from Venezuela

• Screen size should be 20 mesh or larger (to avoid Screen size should be 20 mesh or larger (to avoid plugging)plugging)

• Acidify water to pH 4.5 (citric acid or other) prior Acidify water to pH 4.5 (citric acid or other) prior to adding Veratran Dto adding Veratran D

• SABADILLASABADILLA – Veratran D– Veratran D

• Do not use additives (is a stomach poison and may Do not use additives (is a stomach poison and may reduce thrips feeding activity)reduce thrips feeding activity)

• More effective in warm weather (when thrips are More effective in warm weather (when thrips are actively feeding)actively feeding)

• Not persistentNot persistent (50% gone after 4 days, control (50% gone after 4 days, control may last 1-3 weeks)may last 1-3 weeks)

Avocado Pest Avocado Pest ResistanceResistance

Pesticide Resistance – Pesticide Resistance – A Major Concern with Avocado A Major Concern with Avocado

PestsPests

• Loss of persea mite susceptibility to Agri-Loss of persea mite susceptibility to Agri-

Mek seen in a Ventura Co. avocado groveMek seen in a Ventura Co. avocado grove

(Humeres & Morse 2005a, (Humeres & Morse 2005a, in pressin press))

• Avocado thrips resistance to Veratran D Avocado thrips resistance to Veratran D

seen in two Ventura Co. avocado grovesseen in two Ventura Co. avocado groves

(Humeres & Morse 2005b, (Humeres & Morse 2005b, submittedsubmitted))

• History of citrus thrips resistance on citrusHistory of citrus thrips resistance on citrus

• Loss of citrus thrips susceptibility to Agri-Loss of citrus thrips susceptibility to Agri-

Mek seen in a Ventura Co. citrus grove with Mek seen in a Ventura Co. citrus grove with

concurrent loss in susceptibility to Successconcurrent loss in susceptibility to Success

• Avocado thrips resistance monitoring Avocado thrips resistance monitoring

recently initiatedrecently initiated

Pesticide Resistance – Pesticide Resistance – A Major Concern with Avocado A Major Concern with Avocado

PestsPests

History of Citrus Thrips Pesticide Resistance History of Citrus Thrips Pesticide Resistance DevelopmentDevelopment

Year First Used Year First Used Year PesticideYear PesticidePesticide Pesticide CommerciallyCommercially Resistance Resistance AppearedAppeared

Tartar emeticTartar emetic 19391939 19411941

DDTDDT 19461946 19491949

Veratran DVeratran D 19481948 ????

DieldrinDieldrin 19531953 19541954

MalathionMalathion 19541954 19611961

DimethoateDimethoate 1969 1969 aa 19801980

CarzolCarzol 1972 1972 bb 19861986

BaythroidBaythroid 19911991 19961996

Agri-MekAgri-Mek 19941994 ?? (2004)?? (2004)SuccessSuccess 19981998 ?? ?? (reports investigated)(reports investigated)

a a Registered for use on non-bearing citrus in 1962.Registered for use on non-bearing citrus in 1962.bb Not used extensively until dimethoate resistance appeared in the early Not used extensively until dimethoate resistance appeared in the early 1980’s.1980’s.

Current Citrus Thrips Resistance Current Citrus Thrips Resistance MonitoringMonitoring

• Agri-Mek registered for use against citrus thrips Agri-Mek registered for use against citrus thrips

in 1994in 1994

• Citrus grove in Ventura County sprayed 8 times Citrus grove in Ventura County sprayed 8 times

with Agri-Mek for citrus bud mite controlwith Agri-Mek for citrus bud mite control • 1 spray in 1997, 1 in 1998, 2 in 1999, 2 in 2000, 1 in 1 spray in 1997, 1 in 1998, 2 in 1999, 2 in 2000, 1 in

2001, 1 on 28 April 20032001, 1 on 28 April 2003

• Lesser citrus thrips control observed in 2002 and Lesser citrus thrips control observed in 2002 and

20032003

• Colony started October, 2003Colony started October, 2003

• Bioassay done June. 2004Bioassay done June. 2004

Avocado Thrips Resistance Avocado Thrips Resistance MonitoringMonitoring

• We have recently initiated field monitoringWe have recently initiated field monitoring

• If you have a grove without past exposure to Agri-Mek If you have a grove without past exposure to Agri-Mek

and Successand Success

• OrOr a grove with substantial past exposure to Agri-Mek a grove with substantial past exposure to Agri-Mek

and/or Success and observed a lack of field control,and/or Success and observed a lack of field control,

• Please contact Dr. Eduardo Humeres:Please contact Dr. Eduardo Humeres:

eduardoh@ucr.edu or (951) 827-5443eduardoh@ucr.edu or (951) 827-5443(Please note we are limited in how many tests we can do)(Please note we are limited in how many tests we can do)

Avocado Thrips Avocado Thrips BioassayBioassay

Mu

ng

er

Cells

Mu

ng

er

Cells

Mu

ng

er

Mu

ng

er

Cells

Cells

Transfer early second Transfer early second instar larvaeinstar larvae

Avocado Thrips Resistance to Avocado Thrips Resistance to Veratran DVeratran D

• In contrast to citrus and citrus thrips In contrast to citrus and citrus thrips (no resistance suspected; material (no resistance suspected; material used on citrus since 1948), clear used on citrus since 1948), clear resistance to Veratran D seen in one resistance to Veratran D seen in one avocado thrips population in Ventura avocado thrips population in Ventura Co.Co.

• Grove 4 in Ventura Co.: 10.9-fold Grove 4 in Ventura Co.: 10.9-fold resistance developed after 6 Veratran resistance developed after 6 Veratran treatments over two yearstreatments over two years

Resistance Resistance reversionreversion

• Study the reversion of avocado Study the reversion of avocado thrips resistance to sabadilla in thrips resistance to sabadilla in the Camarillo (Grove 4) strainthe Camarillo (Grove 4) strain

19 AUG 199903 NOV 200309 DEZ 200330 JAN 2004

Reversion of avocado thrips resistance to sabadilla in the Camarillo strain

Resistance Resistance reversionreversion

• The observed reversion of resistance The observed reversion of resistance does not tell us how long adequate does not tell us how long adequate control with Veratran D would persistcontrol with Veratran D would persist

• How quickly would the population How quickly would the population regain resistance ?regain resistance ?

Persea Mite BioassayPersea Mite Bioassay

Califo

rnia

Califo

rnia

Adult FemaleAdult Female

Persea mitePersea mite

Plastic box Plastic box bioassaybioassay

Persea Mite Pesticide Susceptibility Persea Mite Pesticide Susceptibility TestingTesting

• Agri-Mek first available under the avocado Agri-Mek first available under the avocado

thrips Section 18 in 1999thrips Section 18 in 1999

• 7 groves monitored for persea mite 7 groves monitored for persea mite

susceptibility to Agri-Mek in 2003susceptibility to Agri-Mek in 2003

• One grove in Oxnard treated 7 times over One grove in Oxnard treated 7 times over

2000 - 2003 showed a loss of persea mite 2000 - 2003 showed a loss of persea mite

susceptibility to Agri-Mek susceptibility to Agri-Mek • 4 treatments spring 2000-2004 for avocado thrips4 treatments spring 2000-2004 for avocado thrips

• 3 treatments fall 2000-2003 for persea mite3 treatments fall 2000-2003 for persea mite

Persea Mite Field Pesticide Susceptibility - Agri-Mek

0.1

1

Rainbow Bonsall-1 SantaPaula

Bonsall-2 Goleta Fallbrook Oxnard

Strain

LC

50

Lo

g(m

g [

AI]

/lite

r)

a a

b

ab a aa

We must find an alternative We must find an alternative to Agri-Mek for Persea Miteto Agri-Mek for Persea Mite

• Acramite (bifenazate)Acramite (bifenazate)

• Zeal (etoxazole)Zeal (etoxazole)

• FujiMite (fenproximate)FujiMite (fenproximate)

• Kanemite (acequinocyl)Kanemite (acequinocyl)

• Envidor (spirodiclofen)Envidor (spirodiclofen)

• Standard: Agri-MekStandard: Agri-Mek

– CromptonCrompton

– ValentValent

– NichinoNichino

– ArvestaArvesta

– BayerBayer

– SyngentaSyngenta

SummarySummary

Evidence for Concern Regarding Evidence for Concern Regarding Avocado Pest ResistanceAvocado Pest Resistance

1.1. Avocado thrips resistance to Veratran D Avocado thrips resistance to Veratran D

detected in two groves in Ventura Co.detected in two groves in Ventura Co.

2.2. Loss of persea mite susceptibility to Agri-Loss of persea mite susceptibility to Agri-

Mek seen in a Ventura Co. avocado groveMek seen in a Ventura Co. avocado grove

3.3. History of citrus thrips developing resistance History of citrus thrips developing resistance

to 5 classes of chemistry (8 chemicals) since to 5 classes of chemistry (8 chemicals) since

19411941

4.4. Loss of citrus thrips susceptibility to Agri-Mek Loss of citrus thrips susceptibility to Agri-Mek

seen in a Ventura Co. citrus grove (with seen in a Ventura Co. citrus grove (with

concurrent loss of Success susceptibility)concurrent loss of Success susceptibility)

5.5. Only Success (same class of chemistry as Agri-Only Success (same class of chemistry as Agri-

Mek) and Veratran D currently available as Mek) and Veratran D currently available as

alternatives for avocado thripsalternatives for avocado thrips

Evidence for Concern Regarding Evidence for Concern Regarding Avocado Thrips Resistance to Agri-MekAvocado Thrips Resistance to Agri-Mek

Avocado Thrips ManagementAvocado Thrips Management

• Agri-Mek is a Agri-Mek is a remarkably effectiveremarkably effective material for material for

avocado thrips control with minimal avocado thrips control with minimal

detrimental impact on natural enemiesdetrimental impact on natural enemies

• Few effective alternative control materials are Few effective alternative control materials are

likely to become availablelikely to become available

• We We must conserve avocado pest susceptibilitymust conserve avocado pest susceptibility Limit Agri-Mek sprays to once per year maximumLimit Agri-Mek sprays to once per year maximum

Find an effective alternative for persea mite Find an effective alternative for persea mite

controlcontrol

This research was supported in This research was supported in part by grants provided by the part by grants provided by the California Avocado CommissionCalifornia Avocado Commission

AcknowledgmentsAcknowledgments

• Pest Control AdvisorsPest Control Advisors: : Jim Davis, Jim Davis, Charlie Gribble, Matt Hand, Dave Charlie Gribble, Matt Hand, Dave Machlitt, Mark Nyberg, Tom RobertsMachlitt, Mark Nyberg, Tom Roberts

• UC Cooperative ExtensionUC Cooperative Extension: : Gary Gary Bender, Ben Faber, Eve Oevering, Phil Bender, Ben Faber, Eve Oevering, Phil PhillipsPhillips

• CACCAC: : Steve Peirce, Guy WitneySteve Peirce, Guy Witney

• Many cooperating avocado growersMany cooperating avocado growers