0$11$&23# Resistance: Theory & Practice … · 2010-02-05 · 2008 ESA, P-IE Section Symposium, Reno, NV November 18,2008 Ellsworth, Palumbo, Fournier, Carriere Ellsworth/UA Population

1

2008 ESA, P-IE Section Symposium, Reno, NV November 18,2008

Ellsworth, Palumbo, Fournier, Carriere

Ellsworth/UA

!"#$%&'(")&'*$+&"+,-'.+$,,/0$11$&23#

+",2,34%0"'14%45"1"%3'$6'!"#$%$&

'&(&)$'7'894:4)'";4)<4:$%'$6'5+$<9

4&$9:$%'$6'%"$%20$:%$2&'5<2&")2%",

="3"+'.>'?)),@$+3AB'C$A%'=4)<1*$BD)'E$<+%2"+B'F;",'.4++2"+"

D+2G$%4'=",3'H4%45"1"%3'."%3"+'IJ"94+31"%3'$6'?%3$1$)$5#

K%2;"+,23#'$6'D+2G$%4

2008 ESA P-IE Section Symposium, Reno, NV Paper #0635

In Arizona, we are investing considerable IPMresources to research, develop, and analyzespatially-explicit data that can be used in advisingclientele and in evaluating programs.

In one such program, we have a WR-IPM fundedproject to evaluate the adoption of cross-commodity IPM and resistance managementguidelines for whiteflies by growers of cotton,vegetables and melons in Arizona.

These guidelines were developed in a processspear-headed by Dr. John Palumbo, our Vegetableresearch and extension entomologist. I will reviewthese guidelines as they relate to our analyses ofadoption that requires understanding of pestmanagement “Beyond Field Borders.”

2



Ellsworth/UA

Resistance: Theory & Practice

No ChangeNo ChangeNo ChangeNo ChangeReducedReducedpyriproxyfen

NoNo Change?Change?ReducedReducedNo Change?No Change?imidacloprid

YesYesReducedReducedReducedReducedCompound X

Change inManagement

ReducedPerformance

ReducedSusceptibility

Genetic Basis

A problem of rhetoric

? ? ?

Resistance is an issue all too familiar to Arizonagrowers. Unfortunately, however, there seems tobe insufficient rhetorical breadth to have adiscussion about “resistance” without creatingpolarized views of the subject. The word itself isused to describe alleles, individuals, andpopulations. This creates a discordance betweenresistance theory and resistance management inpractice.

It was important from the beginning to be clear onthese points with growers and pest managementpractitioners so as not to oversimplify the issue norbuild-up unrealistic expectations or unreasonablefears.

3



Ellsworth/UA





Change inManagement

ReducedPerformance


Genetic Basis


? ? ?

A problem in discussions about “resistance” is thelinkage of this evolutionary phenomenon withperformance of a product in the field and thenagain its relationship to any changes in practitionermanagement. In a well-behaved system, textbookeven, resistances identified to compound X aredocumented as reduced susceptibilities in somebenchmarked assay system from field-collectedindividuals or their progeny; this discovery isconcomitant with documented reductions ofperformance of the compound in the system ofinterest; and then all this relates directly totangible changes in practitioner management as aconsequence of this resistance in field populations.

4



Ellsworth/UA





Change inManagement

ReducedPerformance


Genetic Basis


? ? ?

Sometimes resistance in theory and practice alignwell with this textbook understanding. But thereare exceptions. In recent studies with Dr. TimDennehy, we were able to show consistentreductions in susceptibilities of Bemisia tabaci (B-biotype) whiteflies in Tim’s statewide monitoring ofpyriproxyfen. Through detailed and precise fieldbioassays conducted over 3 seasons, our labdetermined that there was no identifiable change infield performance of Knack since its first use 10years earlier. Not surprisingly, the practitioners didnot perceive a widespread problem and did notalter their management as a result. This discord-ance between lab bioassay and field manifestationsof resistance can cause the very polarization amongacademics and practitioners we wish to avoid.

5



Ellsworth/UA





Change inManagement

ReducedPerformance


Genetic Basis


? ? ?

Pyriproxyfen usage has declined over the last 5+years because of a stabilization of our system andthe availability of alternatives. Imidacloprid, as thefirst neonicotinoid to be used in the U.S., has beenkeystone to the cross-commodity managementsuccesses we have enjoyed for the past decade ormore. Whitefly management in melons, vegetablesand even cotton depend on the preservation ofsusceptibilities to this class of insecticides. Ourchallenge when we started cross-commodityguidelines development was to convince growersthat it was in their best interest to proactivelymanage this entire class of chemistry. Yet, we hadno a priori knowledge of the resistancerelationships that would be operational in apractical context.

6



Ellsworth/UA

Spring MelonsWinter Vegetables

Shared Whiteflies and Shared Chemistries

Among Key Whitefly Hosts

CottonFall Melons

Intercrop Interactions

In AZ, our desert ecosystem is transformed bywater into a very complex agroecosystem. AZ’s yearround growing season provides for a sequence ofcrop plants, winter vegetables like broccoli, lettuce,other cole crops, spring melons (esp. cantaloupes),summer cotton, and fall melons. These crop islandsprovide for perfect habitat for whiteflies, and ourfocus was on the intercrop interactions that werepossible with this pest and that demanded a highlevel of integration in our IPM programs.

Photo credit: JCP

7



Ellsworth/UA

Whitefly X-IPM……depends on cooperation

among grower’s of cotton, spring &

fall melons, & vegetables.

Singular attempts to deploy recommendations inone crop especially for a mobile, polyphagous pestseems futile, when registrations of key chemistriesare broad across multiple crops. Thus, our cross-commodity effort concentrates on elements wherewe can integrate our practices across multiplecrops. Resistance management is a sharedresponsibility that extends across commodityborders. Cross-commodity cooperation can be keyto the sustainability of a resistance managementplan, and in Arizona, we have achieved someremarkable agreements among growers of severalkey whitefly crop hosts, which I will now detail.

8



Ellsworth/UA

IPM & IRM guidelines emerged from a stakeholder-

engaged process; simple yet ecologically-relevant

The specifics of the stakeholder process are beyondthe scope of what I can cover in this presentation.However, I can say that this was not a desktopexercise limited to 1 or 2 people. Instead, theseguidelines, which were published and disseminatedin 2003, were the result of a year-long,stakeholder-engaged process spear-headed and ledby Dr. John Palumbo. And while we did not andnever do have perfect data or information, byengaging clientele directly in the development ofthese guidelines, we were able to forge a verysimple set of rules for neonicotinoid usage. Yetthrough understanding of our system spatially, wealso have ecologically-relevant guidelines as aresult.

9



Ellsworth/UA

Three Common Communities• Cotton-Intensive, Multi-Crop, and Cotton / Melon

Neonicotinoids are critical to our whitefly controlsystem. Yet real and perceived risks for resistanceamong growers of different crops within differentcommunities in Arizona are not the same.

So rather than develop a single rule to be followedstatewide, we attempted to develop guidelines thatcould be applied differentially according to croppingcommunity and proportional to the inherent risks ofwhitefly problems and resistance.

Three cropping “communities” were identified andtargeted for this approach: Cotton-Intensive, Multi-Crop, and Cotton/Melon (not pictured). White =cotton; orange = melons; green = vegetables(mostly lettuce); and gray = non-treated and/ornon-whitefly hosts (mostly small grains, corn,sorghum, and alfalfa).

10



Ellsworth/UA

Population Growth

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

F13 F1F2

F3 F4 F5 F6F7

F8 F9

F10 F11 F12

To illustrate the extreme risks of resistance in ourmost complex cropping system, we can break thesystem down into component parts. First, we viewthe generational production and relative abundanceof whiteflies through time, again, where greenrepresents the contributions of vegetables tooverall whitefly abundance, white for cotton andorange for melons in this example for communitiesin Yuma.

From Palumbo et al. 2003

11



Ellsworth/UA

Past Pattern of Neonicotinoid Use


F13 F1F2

F3 F4 F5 F6F7

F8 F9

F10 F11 F12

Melons

Vegetables

Neonicotinoid

De facto practice, 1993–2003

The second component is the established pattern ofneonicotinoid usage, or really the periods duringwhich residues are present, as shown here forvegetable and melon crops in Yuma valley. Thispattern of usage was the de facto practice for 10years while essentially only soil-appliedimidacloprid was being used, and used ostensiblywithout bioassay detections of resistance. Thislatter fact was supported by the routine resistancemonitoring that Dr. Tim Dennehy and now Dr.Xianchun Li has done statewide over the lastdecade or so.


12



Ellsworth/UA

Cotton

Potential Pattern ofNeonicotinoid Use


F13 F1F2

F3 F4 F5 F6F7

F8 F9

F10 F11 F12

Melons

Vegetables

Neonicotinoid

Not Sustainable

If neonicotinoids were to expand to the cottoncrops in these complex communities, theseproducts would be depended on in the mid-summerwindow as well. Transposing these potential usepatterns over whitefly generations, and thepotential problem becomes apparent. This potentialoverall use pattern for neonicotinoids in thisecosystem is, we believe, not sustainable.


13



Ellsworth/UA

Preserve a Neonicotinoid-free Periodin Multi-Crop Communities


F13 F1F2

F3 F4 F5 F6F7

F8 F9

F10 F11 F12

Melons

Vegetables

Neonicotinoid

Cotton I

IGRs

II*

Non-Pyr

III

Pyr

Thus, we concluded that, despite new registrationsof neonicotinoids, cotton growers should depend onthe original 1996 plan that includes selective IGRsused first, and non-pyrethroid and pyrethroidinsecticides as needed, rather than making use ofthe newly available foliar neonicotinoids in cotton.

This effectively creates a neonicotinoid-free periodthat has been the de facto condition in thesecomplex communities for the previous decade(1993-2003).


14



Ellsworth/UA

Area-Wide Impact

All crops benefit from lower pressures

Our goal is to achieve an areawide impact onpopulations of B. tabaci such that all crops benefitfrom lower pressures on their crops.

15



Ellsworth/UA

Area-Wide Impact…depends on stable

systems of management

to be in place for all

sensitive crops in order

to reduce area-wide

pressure or movement.

Such a system requires stable management to be inplace for all sensitive crops. And this requires thatwe proactively manage susceptibilities in ourwhitefly populations.

16



Ellsworth/UAPalumbo/UA

Areawide Pressure

Admire 1st used

Widespread

use of Admire

IGRs in cotton

introduced

Dome Valley

Palumbo, unpubl. data

Starting in 1993, Dr. John Palumbo had the foresight to initiate an“efficacy monitoring” protocol in commercial lettuce fields, wherehe established untreated blocks of lettuce within commercially-treated fields with soil-applied imidacloprid. In this chart, we seelarge nymphs per sq. cm. (seasonal average), starting in 1993when Admire was 1st used under a Section 18. Pressure wasextreme as seen in the UTC green bar, but Admire did anexcellent job at reducing these numbers. In 1994-1995, we see aperiod where widespread use of Admire was prevalent throughoutthe fall vegetable landscape and numbers were reduced in theUTC by nearly an order of magnitude. In 1996 through today, weenter a period where the IGRs were first registered and used inAZ cotton and used on a wide-scale. The result is anothermagnitude lowering in the overall whitefly density, and what wethink of as area-wide suppression of whitefly populations. 2005was an outbreak year and pressure was heavy everywhere;however, 2007 & 2008 were light whitefly years. Yet, note thehigher densities, even in the standard. Photo credit: JCP

17



Ellsworth/UA

Sharing Neonicotinoids

Neonicotinoid* Limitations:Maximum usage by crop per season

*Seed, Soil, or Foliar

Multi-Crop

Cotton / Melon

Cotton-Intensive 2 — —

1 1 —

0 1 1

Community Cotton Melons Vegetables

Under John Palumbo’s leadership, we developed astakeholder-driven set of guidelines that, in itssimplest form, in essence, restricts neonicotinoidsas a class to just two uses per cropping community.In a Cotton-Intensive community, growers ofcotton there can use up to 2 non-consecutiveneonicotinoids per season, while in Cotton/Meloncommunities, those two uses are shared betweenthe cotton and melon grower. Perhaps mostcontroversial, in the Multi-Crop community, thecotton growers there forego any usage of thischemical class, reserving the two uses to melon andvegetable growers there who are so dependent onthis class for their whitefly control.

18



Ellsworth/UA

Spatial Considerations

• Whitefly “communities”= all those sensitive hostcrops grown within a 2-mile radius annually

– Ecological assumptionbased on flight biology &movement research

– Perceptual assumption thatPest Control Advisors canidentify & anticipateproduction patterns

While the differential risks are obvious, some sortof spatial scale had to be defined. Withoutdiscussing the details today, we defined ourwhitefly “communities” (areas of potentiallyinterbreeding and moving whiteflies) as all thosesensitive host crops grown within a 2-mile radiusannually. This is an ecological assumption based onflight biology (Blackmer, Byrne, et al.) andmovement research (Naranjo & Ellsworth 2005).This also happens to be an area that we believedthat crop consultants (PCAs) could readily identifyand anticipate production and insecticide use in alocal area.

19



Ellsworth/UA

Cross-CommodityAgreements onNeonicotinoid Use

Yuma

Cotton

Vegetables

Melons

1 use

1 use0 uses

2 uses

1 use1 use

Palumbo et al. 2003

HypothesisMCneo < CIneo

I want to emphasize that these guidelines did notcome from a vacuum. They were developed inconsultation with the industries they serve, cottongrowers, vegetable and melon growers,professional crop consultants, and the affectedagrochemical companies. Further, the ecologicalcontext is relevant to the key pest target.Compliance is voluntary, but this project measuresthis explicitly in Arizona and I will share with yousome of this preliminary data.

In particular, we can examine the hypothesis thatcotton growers in Multi-Crop communities shouldbe making less use (if any) of neonicotinoidsrelative to cotton growers in Cotton-Intensivecommunities within similar localities (to control fordifferences in pest pressures).

20



Ellsworth/UA

1080 Data

• ADA Database

• Verified ‘01–‘05 data

• Estimate 70–90% ofcotton insecticidedata is reported on1080

• Section-levelresolution ONLY!

The tools we need to do this assessment include arich database of pesticide use reporting dataacquired from our own Arizona Department ofAgriculture. We do not have 100% mandatory usereporting in AZ (as does CA). However, all custom-applied (for hire) and all aerial applications(upwards of 80%) and some other pesticides mustbe reported to the state via the L-1080 form. Weestimate that for 70-90% of all cotton insecticideapplications are reported to ADA. The data includesthe crop, target pest(s), location (T.R.S.), andproduct and rate.

Our resolution is only down to individual sections,and not individual fields, as only the legaldescriptions are captured in this reporting process.

21



Ellsworth/UA

We also have access to detailed GIS-based cropmaps statewide as maintained by a cotton-groweragency, the Arizona Cotton Research & ProtectionCouncil. Between these two datasets we are able toidentify the cropping make-up of each section andbeyond.

We wished to measure what incentives andconstraints there are in complying with our cross-commodity guidelines. Because the unit of interestis a community, individual behaviors are not asimportant as the adoption by whole groups withineach community. I will present you a simplifiedanalysis that focuses mainly on cotton-growerbehavior only and on the usage of neonicotinoids.But before I show the data, I would like to brieflyexplain the approach we are taking.

22



Ellsworth/UA

Group Adoption• Examine usage of key

insecticides

• Cotton grower in this typeof community should notbe using neonicotinoids

In cotton,

CI: 2

CM: 1

MC: 0

MCneo = 0

In this example, neonicotinoid usage by cottongrowers within Multi-Crop communities shouldequal zero. Thus, we have something we can test,as long as we have a comparable spatial system.

23



Ellsworth/UA

Township• 36 sections

– Each sectionis 1 milesquare

• 9 sections(3x3) roughlyequivalent to“community”

• Section-levelpesticide use;“% of Sprays”

(simplified spatial analysis)

In the U.S., we are fortunate in that the landmassof this country is laid out on a grid that bears alegal description. One unit of this description is the“Township” which is 36 sq. miles in size made up ofa 6 x 6 sectional grid. Each section is 1 mile squareand numbered as shown. Nine sections (3x3) areroughly equivalent to a whitefly cropping“community” as defined in our guidelines.

24



Ellsworth/UA

Community• User in focal

section shouldmake choicesbased on thecommunity inwhich he/sheis embedded

• Cotton usesonly


In this project, we examined communities and thesection level pesticide records for those areas. Inspecific, we will examine neonicotinoid use bycotton growers in each of the 3 community typesdefined by the guidelines. Can a grower perceive“resistance risk” properly in his/her area and followthe applicable guideline?

I.e., A user in a focal section should be makingwhitefly control product choices based on thecommunity in which he or she is embedded.

Note this is a simplified spatial analysis of Section-level percentage averages in cotton only. So, forexample, we will estimate the % of sprays made ina section that contain a neonicotinoid or otherinsecticides.

25



Factors Influencing Adoption

of Guidelines

2001 2002 2003 2004 2005

% S

pra

ys

thiamethoxam acetamiprid dinotefuran

WhiteflyPressure

MarketForcesBehavior

Change

Documenting changes in behavior through timerequires a clear understanding of competing forces& inherent change in the system. Market forces(new registrations) push users towards greaterusage. In 2001, thiamethoxam was available, butby late 2002, acetamiprid became available as well.Still later (2004), dinotefuran was available tocotton growers. All the while, imidacloprid wasavailable as a foliar spray either alone or in mixturewith a pyrethroid. Whitefly pressures also changeover time. In our case, pressures were low butincreasing 2001-04 until 2005 when whiteflypressures were at a decade high. This pushes usageupward. Our impact on behavior should show somekind of decline in usage as a consequence ofdeployment of our educational programs for cottongrowers in Multi-Crop communities.

26



Ellsworth/UA

Cotton Grown WithinDifferent “Whitefly

Communities”

C = Cotton-Intensive

CM = Cotton / Melon

CV = Cotton / Vegetable

CMV = Multi-Crop (cotton, melons, vegetables)

The next few charts will use the following colorscheme to denote the FOUR cropping communitiesidentified in the data. Note that cotton is grown inall four communities and that all data is withrespect to what a cotton grower does in each ofthese communities: simple Cotton-Intensivethrough to the most complex Multi-Crop communitywhere cotton, melons, and vegetables are grown.

Note that heretofore, we did not recognize the“cotton-vegetable” community as a distinctcommunity type, and thus, there are no specificguidelines that dictate usage in this communitytype.

27



Ellsworth/UA

Cotton Communities

Coc GraLaP Mar

MohPim

Pin Yum

Analyses for Yuma and Pinal Co. only

2005

Pinal Yuma

Multi-CropCotton-Intensive

This bubble chart indicates the number and types ofcommunities that grow cotton by county. Asexpected, there are very few Cotton-Intensivecommunities in Yuma county, but they do existthere! Conversely, there are very few Multi-Cropcommunities in Pinal (or Maricopa) counties, butagain they do exist there.

Our analyses will focus on these larger agriculturalcounties where most of the whitefly applicationsare made each year.

28



Ellsworth/UA

Cotton Usage ofNeonicotinoids

Coc GraLaP Mar

MohPim

PinYum

2001 2002 2003 2004 20050

10

20

30

40

50

% S

pra

ys

CottonCommunities

MCneo = 0

% Sprays that contained a neonicotinoid for cottonfields in Cotton-Intensive communities of Yuma Co.These growers should be limited to no more thantwo non-consecutive neonicotinoid sprays (grayline). Cotton neonicotinoid usage started at 0% in2001-2003 and increased as acetamiprid useincreased, topping out at ca. 45%.

Our guidelines were published in 2003 and oureducational efforts were intense to begin with andthen re-intensified in 2005 (red arrow).

29



Ellsworth/UA

Coc GraLaP Mar

MohPim

PinYum


4-fold

MCneo = 0

2001 2002 2003 2004 20050

10

20

30

40

50

% S

pra

ys

Cotton

Multicrop

Communities

Cotton growers in Multi-Crop communities of YumaCo. had very small usage of this class of chemistryin 2001-2002, and significantly higher usage in2003. By 2005, the trend was reversed, presumablyas a result of our education, showing a 4-foldreduction in neonicotinoid usage in comparison tocotton users in Cotton-Intensive communities.

Of course, the guidelines would have suggested noneonicotinoid usage in Multi-Crop communities. Soca. 10% of the applications made were at oddswith the guidelines.

30



Ellsworth/UA

2001 2002 2003 2004 20050

10

20

30

40

50

60

% S

pra

ys

Cotton

Multicrop

Cotton Usage ofpyriproxyfen

Coc GraLaP Mar

MohPim

PinYum

MCk > CIk

Communities

If neonicotinoid usage is going up through time,albeit at different rates, and whitefly controlinvestments are stable, other chemistry must bechanging. In this case, an IGR, pyriproxyfen hasbeen steadily declining in usage in Cotton-Intensivecommunities, obviously in favor of neonicotinoidchemistry (usually acetamiprid). This is consistentwith guidelines in general.

Also, there has been marginal increases inpyrproxyfen usage in Multi-Crop communities andthis suggests that growers there are trying to makeuse of neonicotinoid alternatives.

% Sprays (Pyriprox) Yuma

31



Ellsworth/UA

2001 2002 2003 2004 20050

5

10

15

% S

pra

ys

Cotton

Multicrop

Cotton Usage ofbuprofezin

Coc GraLaP Mar

MohPim

PinYum

MCc < CIc

Communities

Buprofezin, another IGR, is not as popular ingeneral, and is also subject to some cross-commodity constraints on usage in Multi-Cropareas (because of broad registrations). Here again,it appears that growers in Multi-Crop communitiesare minimizing their usage of buprofezin incomparison to Cotton-Intensive communities.

% Sprays (Bupro) Yuma

32



Ellsworth/UA

2001 2002 2003 2004 20050

10

20

30

40

50

% S

pra

ys

Cotton

Multicrop


Coc GraLaP Mar

MohPim

Pin Yum

MCneo = 0

Communities

The conclusions are quite different as we move tothe central part of the state and examine Pinal Co.usage data. Here it would seem that the clienteledo not differentiate their usage of neonicotinoids bycommunity type. The reasons for this are unknownat this time, but qualitative analyses of subjectinterviews should help us understand if this is aproblem with the guidelines, perception of spatialdynamics, or perception of risk, among otherpotential factors. It could be as simple as growersnot recognizing they are operating within a Multi-Crop community, for example.

% Sprays (Neonicotinoids), Pinal

33



Ellsworth/UA

Acetamiprid Use in ALL Cotton

2005 2006 20070

20

40

60

80

100

Intr

ud

er

Ac

res

(%

)

Rest (<2000')

Yuma Co.

User reports (CIL)

4.4-fold difference

11, 13 9, 5 14, 2N ==>

Data until now has all been from pesticide usereports maintained by ADA and only for 2001-2005.This dataset is different; it is from user reports in aCotton Insect Losses process that we conduct eachyear with practitioners and brings our informationforward to 2007. While we cannot separatecommunities spatially, we can contrast Yuma Co.(which is predominated by Multi-Cropcommunities) to the rest of the low desert of AZ(which is predominated by Cotton-Intensivecommunities). Here again, we see that on average,users use less neonicotinoids in cotton in mult-cropped areas in comparison to cotton-intensiveregions. It would appear that the guidelines areobserved in general. (Acetamiprid is the majorcotton neonicotinoid and dominates thismarketplace).

34



PCA Interviews• “Interview guide” approach

• 12 PCAs representing 3major growing regions– 31% “market share” of all

cotton sprays (2001–2005)

– 56% for melons

– 16% for vegetables

• Questions on knowledge ofguidelines, assumptions, &improvements

• Qualitative analysis(preliminary)

In addition to the quantitative analysis of 3rd partydata, we also engaged an extensive qualitativeapproach led by Dr. Al Fournier, who interviewedPCAs about their whitefly management practices.Many hours of interviews were transcribed andanalyzed by Al, and today I’ll share just some of thepreliminary results.

35



Adoption• Positive factors:

– UA outreach

– Many product choices (including new aphicides)

– Unwitting “adoption” (e.g., Yuma MC)

– Low whitefly pressure in recent years

• Negative factors:– PCA flawed assumptions re: communities (e.g., Pinal CI)

– Influence of grower on product choice

– Influence of price on product choice

– Situational factors (e.g., seed treatments in cotton)

• Our assumptions about PCA perceptions werebrought into question

Several factors were cited as influential on PCApesticide choices. They included our outreachprograms and the availability of many productswhich provides much needed flexibility. There wassome unwitting adoption that occurred where PCAswere not really aware of the guidelines butconformed to them nonetheless.

There were negative factors such as grower andprice pressures on product choice, and somesituational factors. Importantly, the assumptionthat PCAs are aware of production patterns aroundthem (for a 2-mile radius) is flawed for some,especially in central AZ where many might assumethey are in “Cotton-Intensive” communities whenin fact there are melons and/or vegetables within 2miles.

36


Ellsworth, Palumbo, Fournier, Carriere !"

Soil Use

(% Treated acres)

0 20 40 60 80 100

Fo

liar U

se

(% T

rea

ted

Acre

s)

0

20

40

60

80

100

Compliance

Non-compliance

Neonicotinoid Soil & Foliar Uses in Lettuce

8$<+0"-''*+*,-./0"12,344563447

User reports (Lettuce)

Adoption

Non-Adoption

Fneo + Sneo ! 100%

Fo

lia

r U

se(%

Tre

ate

d a

cres)

So far, we have examined exclusively cotton-growers behavior. In this chart we are showinghow lettuce growers make use of the neonicotinoidclass of chemistry as reported in user reports of ourVegetable Insect Losses workshops.

With foliar uses on one axis and soil uses on theother, we can test whether they are observing ourguidelines and the labels of some products by notusing foliar neonicotinoids over the top of cropsthat have already used a soil neonicotinoid. So auser reporting 70% soil use and 20% foliar use ofthis class shows potential adoption (total 90%).However, a user who reports 100% soil use AND50% foliar use is clearly outside the guidelines.

Data from Palumbo, unpubl.

37


Ellsworth, Palumbo, Fournier, Carriere !#

Soil Use

(% Treated acres)

0 20 40 60 80 100

Fo

liar U

se

(% T

rea

ted

Acre

s)

0

20

40

60

80

100

2004-2005 (0/15)

2005-2006 (515)

2006-2007 (3/13)

2007-2008 (1/10)

Fall Lettuce

Compliance

Non-compliance

L$%/D&$9:$%-

''''M'I'NO'=.D,

8$<+0"-''*+*,-./0"12,344563447

Adoption

Non-Adoption

Fo

lia

r U

se(%

Tre

ate

d a

cres)

Fneo + Sneo ! 100%


Looking at growers of fall lettuce from 2004-2007,we can see that the majority of pest controladvisors (PCAs) are within the adoption zone. Thereare some examples where non-adoption isoccurring, 9/53.

Data from Palumbo, unpubl.

38


Ellsworth, Palumbo, Fournier, Carriere !$

Soil Use

(% Treated acres)

0 20 40 60 80 100

Fo

liar U

se

(% T

reate

d A

cre

s)

0

20

40

60

80

100

2004-2005 (3/15)

2005-2006 (11/15)

2006-2007 (4/13)

2007-2008 (5/10)

Spring Lettuce

Compliance

Non-compliance

L$%/D&$9:$%-

''''PO'I'NO'=.D,

8$<+0"-''*+*,-./0"12,344563447

Adoption

Non-Adoption

Fo

lia

r U

se(%

Tre

ate

d a

cres)

Fneo + Sneo ! 100%


Things looked good in the fall where they arebattling whiteflies primarily. However, in springlettuce, the picture changes and now shows closerto 50% non-adoption. Why is this? As it turns out,many of these neonicotinoid uses are likelytargeting aphids rather than whiteflies, which areless of a concern in the spring crop. So perceptionof the resistance risk may be quite differentbetween users in the fall vs. users in the spring.

39


Ellsworth, Palumbo, Fournier, Carriere !%

Q12&40)$9+2&'="+6$+14%0"

Q%'.$11"+024)'!+$00$)2

R4+5"'L#19A'J"%,2:",

8$<+0"-''8&9.#(:2,.;<.(9=

'98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '080

10

20

30

40

50

60

70

80

90

100

Re

du

cti

on

fro

m C

he

ck

(%

)

Y = -4.95x + 1.03

R = 0.922

Cooperatoroversprays

John Palumbo has been doing systematicexaminations of imidacloprid efficacy (soil uses) inbroccoli for the past 10 seasons. Charting efficacyrelative to a control shows rather markedreductions in efficacy in these studies. While usersdon’t widely report problems with this use patternand soil uses, especially in fall crops, are still almostuniversally practiced, this is a warning sign that wemust re-consider our management program anddecide whether further steps are needed tostabilize the control system. A dialog is currentlyunderway with clientele through our Cross-Commodity Research and Outreach Programworking group.

40



Ellsworth/UA

• Identify problem through stakeholder feedback– Stable whitefly management threatened by overuse of a

key class of chemistry

• Develop solutions through applied research &education– Analysis of agroecosystem suggests variable risks;

guidelines are generated, published & workshopsconducted

• Assess & measure impacts and changes in clientbehavior– Cotton growers making insecticide use choices based

ostensibly on guidelines

• Develop feedback & make adjustments inresearch & education– New data on imidacloprid performance; new products?

Cooperative Extension Model

What I have detailed today, quickly, is the classicExtension model, where workers identify problemsthrough stakeholder engagement and they developsolutions through applied research and education.These are time-tested standards in Extension.However, a modern program continues with formalassessments that measure impacts and changes inclient behavior. And with this information, we canbenefit from feedback that helps us make neededadjustments in our research & education programs.

Growers did in fact alter their insecticide usepatterns as a result of our guidelines. However,resistance remains a threat to this and otherchemistries. We will have to consider this alongwith other results in the generation of newresearch, new guidelines, and education.

41



Ellsworth/UA



Yes?Yes?ReducedReducedNo Change?No Change?imidacloprid


Change inManagement

ReducedPerformance


Genetic Basis


Coming full circle, we can now summarize what wethink we know about our system wrt neonicotinoidsand imidacloprid specifically. Through much of thisperiod, statewide resistance monitoring datashowed no appreciable change in susceptibility ofour whiteflies to imidacloprid. Yet, the detailed fieldperformance data from John Palumbo’s studies areunequivocal and dramatically document aprogressive decline in performance of imidaclopridespecially in the longest control intervals. Initiallyand for several years, this change did not result inchanges in practitioner practice. However, in thelast 2–3 years, some PCAs have in fact changedpractices by overspraying with foliar and doing sosooner, or substituting a foliar control program forthe soil imidacloprid altogether.

42



Ellsworth/UA

http:http://cals//cals..arizonaarizona..edu/cropsedu/crops

Arizona Department of AgricultureArizona Ag Statistics (AZ-NASS)

Western Region IPM Grants Program

A large group of people are involved in the largereffort to research, develop, and disseminate cross-commodity whitefly management programs [e.g.,T.J. Dennehy, Y. Carriére, C. Ellers-Kirk (all UA); S.Naranjo, J. Blackmer, S. Castle (USDA-ARS); P.Dutilleul (McGill U.); R.L. Nichols (Cotton Inc.); AZCotton Growers Assoc., Western Growers Assoc., AZCrop Protection Assoc.]. In addition, we thank theADA and AZ-NASS for cooperating on thedevelopment of a pesticide use database; WRIPM &Cotton Inc. for providing grant support; and theArizona Cotton Research & Protection Council forproviding GIS mapping support.The Arizona Pest Management Center (APMC) as part of itsfunction maintains a website, the Arizona Crop Information Site(ACIS), which houses all crop production and protectioninformation for our low desert crops, including a PDF version ofthis presentation for those interested in reviewing its content.

Photo credit: J.Silvertooth

43



Ellsworth/UA

Community• Each section

is a memberof 8 othercommunities

• Number offields notcurrentlyknown

• Section %averages only


Bear in mind that one section can be a member of 8other communities that might be variably defined.But that again, the user will make decisions basedon the cropping pattern in the surrounding 8sections plus in the focal section.

At this time, we have not quantified the number offields per section. So all response variablesdiscussed today will be Section % averages, ratherthan uses / field or total acres.

44



Ellsworth/UA

Coc GraLaP Mar

MohPim

PinYum

2001 2002 2003 2004 20050

20

40

60

80

100

% S

pra

ys

Cotton

Multicrop

Cotton SpraysTargeting Whiteflies

Similar investment

As a check to be sure that there are not largedifferences in pressure or spray investments forcotton by community, we can look at the % ofSprays that were targeting whiteflies. In general,both communities are spraying whiteflies about 60-80% of the time.

% Sprays (wf target) Yuma LSmeans

45



Ellsworth/UA

Neonicotinoids

Knack

Courier

Others

Insecticides in Yuma

Cotton-Intensive

Multi-Crop

2003 2004 2005

N > 234

N = 11–20

Neonicotinoids

Pyriproxyfen

Buprofezin

Others

Reviewing the dynamics of major chemistries overtime, we see all three trends simultaneously.Neonicotinoid usage has gone up in bothcommunity types over time, but less so in Multi-Crop communities. Pyriproxfen usage has remainedsteady in these same communities, but declined inCotton-Intensive communities. Buprofezin is notused very much over this period, but in decliningamounts in the Multi-Crop communities.

46



Ellsworth/UA

Insecticides in Pinal

Cotton-Intensive

Multi-Crop

2003 2004 2005

N = 11–20

N > 459

Neonicotinoids

Knack

Courier

Others

Neonicotinoids

Pyriproxyfen

Buprofezin

Others

Usage dynamics over time: While other insecticidesare used generally about 3/4ths of the time,neonicotinoid usage is consistent andundifferentiated by community type are time.

47



Ellsworth/UA

• Identify problem through stakeholder feedback– Stable whitefly management threatened by overuse of a

key class of chemistry

• Develop solutions through applied research &education– Analysis of agroecosystem suggests variable risks;

guidelines are generated, published & workshopsconducted

• Assess & measure impacts and changes in clientbehavior

• Develop feedback & make adjustments inresearch & education

Cooperative Extension Model

What I have detailed so far today, quickly, is theclassic Extension model, where workers identifyproblems through stakeholder engagement andthey develop solutions through applied researchand education. These are time-tested standards inExtension. However, a modern program continueswith formal assessments that measure impacts andchanges in client behavior. With this information,we can benefit from feedback that helps us makeneeded adjustments in our research & educationprograms.

This funded effort is an opportunity for us to investin the 2nd half of our approach: assess, measure,and develop feedback and adjust programs.

Documents

0$11$&23# Resistance: Theory & Practice … · 2010-02-05 · 2008 ESA, P-IE Section Symposium, Reno, NV November 18,2008 Ellsworth, Palumbo, Fournier, Carriere Ellsworth/UA Population