Bemisia tabaci, Biotype B Integrated Control · 2009. 5. 4. · DAG

North Carolina State University 13 April 2009

50 years of the ICC & Moving AZ Forward 1

Ellsworth/UA

!"#$%&'(#)*#+,%#-.+%/'&+%01).+')2#1).3%4+5#6)78./#+,%1).3%4+#&.0#-942%9%.+&:).*)';&'0#8.#<'8=).&

>%+%'#?22(;)'+,#@#A+%7%#B&'&.C)

D.87%'(8+$#)*#<'8=).&E

<'8=).&#>%(+#6&.&/%9%.+#1%.+%'#FG%4&'+9%.+#)*#?.+)9)2)/$

@

DAG<H<IAE#<'80#J&.0(#</'83K2+K'&2I%(%&'3,#1%.+%'

North Carolina State University Seminar Series

This is a story that I’ve have told before: indifferent venues, and to different audiences.However, it is a significant success story, and wehad the opportunity to celebrate 50 years of theIntegrated Control Concept pioneered by Stern andhis colleagues at the last PB-ESA meeting, with myco-author, Steve Naranjo of USDA-ARS, ALARC. Wehave been working in the cotton-whitefly systemfor more than 15 years. My goals today are tooutline how we are attempting to implement andmove this concept forward in Arizona, and to focusin more detail on the chemical and biologicalcontrol elements of our IPM system. What I thinkyou will see is that much of what we do today inIPM can trace roots back to Stern’s very robust ICC.

Invited seminar, 1 hr.


50 years of the ICC & Moving AZ Forward

Ellsworth/UA

The IntegratedControl Concept

Vernon M. SternRay F. Smith

Robert van den BoschKenneth S. Hagen

1959

The Integrated Control Concept was published byStern and his Californian colleagues in Hilgardiasome 50 years ago. Their experiences were in fieldcrops in California including alfalfa, cotton andsafflower. The insights provided in this paper formthe conceptual basis for IPM today. If you have notread or re-read this paper recently, I highlyrecommend it! It is an extraordinary piece withincredible insight into the basic ecology thatunderpins the control system. We are trying stilltoday to implement many of the ideas broughtforward in this work 50 years ago. It is in fact quitehumbling to be working in IPM today and realizingjust how much they knew back then and how muchmore we need to do today to fully realize theirvision.



“Applied pest control whichcombines and integrates

biological and chemical control.Chemical control is used as

necessary and in a manner whichis least disruptive to biological

control.”

Stern, Smith, van den Bosch

& Hagen 1959, Hilgardia

Integrated Control

At its heart, Stern’s ICC boils down to this…

The system that I have worked on ever sincearriving in Arizona with Steve Naranjo and otherswas like a clean slate.



Ellsworth/UA

Bemisia tabaci, Biotype B

• 33 !g

• > 600 hosts

• Mobile adult form

• Introduced to U.S.in late 1980’s andAZ in early 1990’s

• Reduces yields,contaminates withhoneydew & vectorsviruses

This biotype of Bemisia tabaci was introduced tothe U.S. in the late 1980’s and invaded AZ in theearly 1990’s, where it displaced our native A-biotype in a matter of a few years. The native strainwas of little practical consequence in cotton, rarelyrequiring the attention of pest managers. The B-biotype on the other hand was devastating,reducing yields, contaminating agriculturalproducts with honeydew and vectoring viruses.



Ellsworth/UA

Mass Movement

J. Hatch

This is a mobile insect, as is evident in this nowfamous slide showing “clouds” of whiteflies movingacross a newly planted vegetable field in theImperial Valley of California in the early 1990s.Pressures were so extreme at that time that drivingthrough the valley at that time would actually cloudup your windshield. This was a nearly impossiblepest management situation.



Ellsworth/UA

$100MProblem

Sticky cotton could notbe sold at a premiumprice after outbreaks in1992 & 1995.

The problem starts with the insect, but the driver ofthis system is what is shown in this micrograph of acotton thread. While yield losses have always beena potential problem, the real problem is thedeposition of honeydew on exposed cotton lint thatthen is processed, if it can be processed at all, andspun into a thread loaded with these defects. So a100 million dollar problem starts with honeydewdropping on leaves, and cotton fibers, and finisheswith knotted fabrics or yarns. Costly shutdowns ofmills for cleaning motivates the marketplace.Marketers play it safe by avoiding buying fiber fromwhole areas where previous episodes of stickycotton have occurred. This has a chilling effect oncotton prices locally. [Photo credits: InternationalTextile Center (Lubbock, TX), upper left, Lynn Jech(inset), USDA (wf), pce (remaining)].



“Integrated control is mostsuccessful when sound

economic thresholds have beenestablished, rapid samplingmethods have been devised,and selective insecticides are

available.”

Stern, Smith, van den Bosch

& Hagen 1959, Hilgardia

Integrated Control

The steps for realizing the Integrated ControlConcept were very clearly laid out by Stern andcolleagues in 1959:

You need economic thresholds, rapid samplingmethods, and selective insecticides.

When the whitefly hit us as a brand new andinvasive pest of our agroecosystem, we had none ofthis.



Ellsworth/UA

Whitefly IPM 1991

We were starting from nothing in 1991.

The form that our IPM plan takes today was noteven conceivable with the severe pressures wewere facing and the vast gaps in our knowledgebase that were present at the time.

An entire scientific industry mobilized to addressthe problem, and Steve and I began ourcollaboration with each other as well as with manyother academic and industry stakeholders.



Ellsworth/UA

Whitefly IPM 1993

By 1993, we at least had identified somecommercial chemistries that could be used tocombat this problem. We had some idea of thealternate host interactions that were present in ourdesert agroecoystem and were faced with tellinggrowers to shorten their season at all costs to avoidmajor damage from whiteflies.



Ellsworth/UA

Whitefly IPM 1995

By 1995, we had major progress in the upper layersof the IPM pyramid, in sampling and chemical use.We were also gaining more insight into theareawide impact of whitefly movement and cropplacement.



Ellsworth/UA

Whitefly IPM 1996–1999

In 1996, we introduced some key selectivechemistry that changed everything for us. Itenabled a broader base of avoidance tactics, andwe were well on our way to stabilizing a previouslyand seriously destabilized system.



Ellsworth/UA

Whitefly IPM 2000–

By 2000, we had installed some critical cross-commodity agreements among cotton, vegetableand melon producers and our IPM plan came intofull focus. This pyramid metaphor serves as ourheuristic representation of whitefly IPM in Arizonacotton. A crucial element added, effective ANDselective chemistry, starting in 1996. This continuesto be our operational IPM plan. At its simplest, it isjust 3 keys to management, Sampling, EffectiveChemical Use, and Avoidance. One can break thisdown further and examine each building block ofthe pyramid and see an intricate set of interrelatedtactics and other advances that have helped tostabilize our management system. However, I willconcentrate my comments on those elementsrelevant to the selectivity of the strategy.



Ellsworth/UA

GEP

EIL

ET

Critical DensitiesStern et al. 1959

Stern and colleagues developed an enduring set ofconcepts in their landmark paper, all having to dowith critical densities of pest insects and rootedfundamentally in ecology of population regulation. Iwill not dwell on these aspects as they relate to ourwhitefly system, except to say that they werecritical to our success, too, and covered in thecompanion presentation by S. Naranjo.

The GEP is an ecological “set-point” for apopulation that may be, as in our case, be wellabove a critical injury level, the EIL. In these cases,treatments are regularly required to prevent pestinsects reaching the EIL. The level for timing theseinterventions is known as the economic threshold.After treatment, repeated for a chronic pest, amodified sub-economic density is achieved.



Ellsworth/UA

Economic Injury Level

• Stone, J. D., and L. P. Pedigo. 1972.Development and economic injury level for thegreen cloverworm on soybean in Iowa. J. Econ.Entomol. 65:197-201.

• Norton, G. A. 1976. Analysis of decision makingin crop protection. Agro-Ecosyst. 3:27-44.

• Pedigo, L. P., et al. 1986. Economic injurylevels in theory and practice. Ann. Rev.Entomol. 31:341-368.

C = Costs; P = Price; D= Damage; K = Damage avoided

EIL = C (PDK)

The EIL is a major concept in IPM; however, it isnon-trivial to develop and implement. In fact, ittook 13 years after the ICC was published beforethe very first EIL for an insect pest was published.Various economic theories have been applied to thisproblem over the years, but even today, there areprecious few examples of well-developed, market-sensitive EILs developed in pest management.

Naranjo and others developed an EIL for thissystem when it was based on broad-spectrumcontrol technologies.



Ellsworth/UA

Selective Insecticide

“Chemical control should act as a complement to

the biological control.”

Chemical and biological control... “with adequateunderstanding, can be made to augment oneanother.”

“An insecticide which while killing the pestindividuals spares much or most of the otherfauna, including beneficial species, eitherthrough differential toxic action or through themanner in which the insecticide is utilized(formulation, dosage, timing, etc.).”

Stern et al. 1959.

At the heart of Stern’s paper, they make severalimportant, simple, and straight-forward statementsabout chemical control. Namely, chemical controlshould complement biological control; and the twotactics should be made to augment one another.Within the ICC there is this pervasive idea that aninsecticide should kill the target but spare mosteverything else. Given the times, and given thetools available at the time (DDT, toxaphene), theseideas were rather controversial especially withinthe agricultural community. Also, much of Stern’shopes for selective insecticides were pinned on thedevelopment of new organophosphate andcarbamate insecticides! But this idea that therewere fauna worth sparing is what was remarkable,an idea that has gained recent momentum…



Ellsworth/UA

• Daily (1997)

– “… the conditionsand processesthrough whichnatural ecosystems,and the species thatmake them up,sustain and fulfillhuman life”

From Millennium Ecosystem Assessment (2005)

…in the development of the concept of “ecosystemservices.” Ecosystem services are quite simplydefined as those things contained in ourecosystems that sustain our life. Daily’s originaldefinition focused on “natural” systems; however,the concept has expanded appropriately toencompass the interrelationships between naturaland managed ecoystems.

These services are often broken down intocategories. Provisioning is an obvious ecosystemservice of our agricultural systems; food productionfrom our ecosystems is absolutely essential.



Ellsworth/UA

“…these regulating factors actually keepthousands of potentially harmful

arthropod species permanently beloweconomic thresholds.”

Stern et al. 1959

– pollination

– pest control, e.g.,via conservationbiological control

As important as this is now, imagine that Stern andhis colleagues recognized this concept more than50 years ago, by stating…

It is satisfying now as an applied entomologist tosee a renaissance in thinking and implementationof these concepts in agroecosystems. But humblingto know that these ideas have been around for 50years.

Stern recognized that regulating services are thedomain where conservation biological controlexists.



Ellsworth/UA

ConservationBiologicalControl

• In-field lowering of target

pest general equilibrium

position

• Areawide lowering of

primary & secondary pest

densities

• Prevention of secondary pest

outbreaks

• Minimizes pest resurgences

Conservation biological control (CBC) can functionto lower the general equilibrium position of thetarget pest in the field under management, but alsoof other primary and secondary pests areawide.CBC is often critical to prevention of secondary pestoutbreaks and minimization of pest resurgences.



Ellsworth/UA

Diminished by use of pesticidesDiminished by use of pesticides

The Millennium Ecosystem Assessment, which wascompleted on a global scale in 2005, concluded thatpesticide use was diminishing these regulatingservices and in fact replacing pest control bynatural enemies. It is precisely here where we needselective pesticides more than ever. A well-designed and deployed selective pesticide shouldfully complement the pest control provided bynatural enemies.



Ellsworth/UA

WhiteflyIPM… …depends on 3 basic keys

I have been teaching about whitefly IPM togrowers from this pyramid metaphor for more than10 years. But today, I wish to focus on thecompatibility between chemical and biologicalcontrols that are so important to the ICC and to thesuccess of our IPM plan today.



Ellsworth/UA

NewGuidelines

• Identifyprevention,monitoring &controlpractices

• Chemical usesuggestions

• Flexible &adaptive to awide range ofconditions

Steve Naranjo and I have conducted detailedresearch on this system nearly continuously sincetheir introduction in 1996. They have beencontinually refined and taught to growers regularlyin my Extension program. The guidelines wererevised and re-issued in 2006, and I would like toacknowledge our other collaborators, Tim Dennehy(who now works at Monsanto), Bob Nichols ofCotton Incorporated who has helped sponsor muchof the work I will review, and John Palumbo ourExtension vegetable entomologist.

Within are detailed chemical use suggestions thathighlight the effective and selective use of keyinsecticides.



Ellsworth/UA

Whitefly IPM

Central to our IPM plan is effective & selectivechemistry. Installing and validating this buildingblock of our plan was critical to our strategy.



Ellsworth/UA

Egg

Crawler

2nd 3rd

4th, “pupa”

AdultKnackKnackMajorMajor

Points ofPoints of

InsectInsect

GrowthGrowth

RegulationRegulation

CourierCourierbuprofezinbuprofezin

pyriproxyfen

Pyriproxyfen is a juvenoid, a juvenile hormonemimic, that does not kill adults outright -- neitherIGR does this -- however, Knack sterilizes adultfemales and developing eggs prior to blastokinesis.Knack may also prevent metamorphosis. Buprofezinis entirely different chemistry structurally andfunctionally. It is a chitin inhibitor and as suchinterrupts the molting of each nymphal instar.

Both of these IGRs are selective in our system,ultimately killing only our target pest, the whitefly.



Ellsworth/UA

Egg

Crawler

2nd 3rd

4th, “pupa”

Adult

OberonOberon

spiromesifen

• Lipid biosynthesis inhibitor

• Effective mainly on nymphs

Spiromesifen is a lipid biosynthesis inhibitor, alsowith very little direct adult activity, and majoraffects on younger nymphs. It was introduced intoour system more recently (2005).



Ellsworth/UA

Egg

Crawler

2nd 3rd

4th,

“pupa”

Adult

IntruderIntruder

acetamiprid

• Neonicotinoid

• Effective against all stages

Acetamiprid is arguably biorational, largely throughthe differential sensitivity of the nicotinicacetylcholine receptor between arthropod andmammalian systems. It, too, came later (2002), butproducers have made this the number one whiteflyinsecticide largely because of its excellent adultactivity and acropetal systemic action.



Ellsworth/UA

Effective & SelectiveChemistry?

• Pyriproxyfen (Knack), reduced-risk pyridine, juvenilehormone mimic, Group 7C

• Buprofezin (Courier), reduced-risk thiadiazine, chitininhibitor, Group 17

• Acetamiprid (Intruder), reduced-risk neonicotinoid,nicotinic acetylcholine agonist, Group 4A

• Spiromesifin (Oberon), reduced-risk tetronic acid,

lipid synthesis inhibitor, Group 23

So today these are our 4 best, most effectivechemistries. In terms of selectivity, Knack, at leastin our system (AZ cotton), is fully selective. Courier(or Applaud), too, is fully selective. Intruder (orAssail, a neonicotinoid), however, is in fact notselective. It is highly effective, but actually willreduce natural enemy densities. Of course,relatively speaking, it is still more selective than thealternatives, pyrethroid mixtures or high rates ofendosulfan for example.

Oberon provides rate-sensitive selectivity, anotherconcept mentioned by Stern et al., where lower,whitefly rates are fully selective, but highermiticidal rates are somewhat less selective.



Ellsworth/UA

Historical ComparisonsKnack 1996(IGR Example)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

0

1

2

3

June July August September

La

rge

Ny

mp

hs

pe

r d

isk 1996

Our IGRs are the classic example of selectivity inaction. We’ve been running commercial scaledemos for years, starting in 1996 with the whiteflyIGRs. In this one example with Knack in 1996, wecan see that we reached threshold (1 large nymphper disk or 40% infested disks), sprayed, densitiescontinued up for a time, and then the populationcollapsed. We know from our studies that thechemical effects of Knack last only a few weeks atbest, but…



Ellsworth/UA


6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk 1996

… through the action of predators especially, andother natural sources of mortality, the whiteflypopulation is maintained below threshold wellbeyond the known period of chemical residual. Weterm this extended suppressive interval present in aselective system, “bioresidual”. We coined this termto better communicate with growers and toaccommodate all the mortality processes present ina selective system, not just those related toconservation biological control.



Ellsworth/UA

Bioresidual

“Combined contribution of

all natural mortality factors

…that allow for lowering of

the general equilibrium

position of the target pest

and long-term pest control

following the use of

selective insecticides.”

bbiioollooggiiccaall

iinnsseeccttiiccee

Naranjo & Ellsworth, in review

Specifically, we define bioresidual as follows:…

In teaching this concept to growers, I used afamiliar icon as a metaphor, the IGR jug. Inessence, our work showed that about half of thecontrol interval could be directly attributable to thetoxic growth-regulating effects of the IGR, whilethe other half was due to the biological orecological sources of mortality that are in placealready but are made more effective by theselective reduction of the previously “out ofcontrol” host, the whiteflies.

This has been a powerful metaphor for explainingwhy one might refrain from mixing IGRs with lessselective materials. I.e., it is tantamount todumping out half of the contents of the IGR jug.



Ellsworth/UA

“Natural Control…the combined actionsof abiotic and biotic elements of the

environment.”

Stern et al. 1959

Here again, Stern had something to say on thetopic…

However, this perhaps represents one of thoserefinements or small advances we have made inthat “bioresidual” is the “natural control” that ispossible when a selective insecticide is used,something that Stern did not explicitly write about.



Ellsworth/UA

IGRs & Natural EnemiesIGRs & Natural Enemies

Central to remedial tactics is an effective chemicalarsenal. In AZ, we have shown that when selectiveoptions are available and effective, huge gains inboth target and collateral control can be achieveddue to much better natural enemy conservation andother natural mortalities. This ecosystem service isa foundational element of “Avoidance,” and onemade compatible with the these specific andselective chemical controls in our system.



Ellsworth/UA


6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk 1996

Returning to our replicated commercialassessments, we can show how durable andpredictable the patterns of control are.



Ellsworth/UA

Knack 1997UTC > 12.8 (9/16)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

7770

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk

1997

Note that starting in 1997, we had replicated UTCsavailable for the first time. Also, note as I stepthrough each year how the maximal populationdensities in the UTCs change each year; however,the pattern of control through in our selectivesystem remains consistent.



Ellsworth/UA

Knack 1998UTC > 3.0 (8/10)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

777 8 8 8

8

8

8

8

8 88

8

8

8

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk 1998



Ellsworth/UA

Knack 1999UTC > 3.3 (8/16)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

777 8 8 8

8

8

8

8

8 88

8

8

8

9 9 99

9

9

9

9

9 9 9

9

9

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk

1999



Ellsworth/UA

Knack 2000UTC > 10.6 (8/3)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

777 8 8 8

8

8

8

8

8 88

8

8

8

9 9 99

9

9

9

9

9 9 9

9

90

0

0

0

0

0

0

0

0

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk

2000



Ellsworth/UA

Knack 2002UTC > 6.4 (9/18)

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

777 8 8 8

8

8

8

8

8 88

8

8

8

9 9 99

9

9

9

9

9 9 9

9

90

0

0

0

0

0

0

0

0

2 22 2

2

22

2

2 2

2

22

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk

2002



Ellsworth/UA

Knack,1996–2002

6

666

66

6

6

6

6

6

6

6

6

6

6

6

6

6

66

7

77

7

7

7

7

7

7

777 8 8 8

8

8

8

8

8 88

8

8

8

9 9 99

9

9

9

9

9 9 9

9

90

0

0

0

0

0

0

0

0

2 22 2

2

22

2

2 2

2

22

0

1

2

3


La

rge

Ny

mp

hs

pe

r d

isk 1996 1998

1997

19992000

2002

Pyriproxyfen

UTC

0 1 2 3 4 5 6 7 8

Seasonal Maximum Density

P = 0.02

When growers experienced difficulties with thisapproach, it was almost always due to problemswith timing. So I used these demonstrations toshow growers that consistent timing of theseslower-acting IGRs gives very consistent results.

On average over the last 13 years, growers havesprayed whiteflies in cotton just 1 time per season.

On average over the 5 years of these replicateddemonstrations, the IGR regime significantlyreduced the maximal seasonal density of largenymphs per disk relative to the untreated controls.



Ellsworth/UA

“…since the insecticide is not apermanent part of the environment, thepest may return to a high level when the

effects of the insecticide are gone.”

Stern et al. 1959

1995: 6.6 spraysLast decade: 1 spray

Stern made an observation that is technically true.Insecticides are not a permanent part of theenvironment, and once gone, pests may return tohigh levels. However, functionally, IGRs and otherselective chemistries in our system have oftenprovided for season-long control of whiteflies in oursystem. Occasionally, growers spray a second timelate in the season.



Ellsworth/UA

Adult Population DynamicsCotton

0.1

1

10

100

300

28-Jun 26-Jul 23-Aug

Adults per leaf

1997 From Naranjo & Ellsworth, 2005

Immigration

Emigration

The reason for this is rooted in the population dynamics incotton. Here we see the number of adults per leaf in bluein unmanaged cotton. When we run a whitefly simulationmodel using the identified mortality rates & bio-fixes foreach generation studied, we initially see exceptionallygood agreement in the predicted adult levels. However,eventually we see that the actual densities of adults trackhigher than what was predicted. We view this asimmigration into the system. In-season, we see very goodagreement between the simulations & the actualdensities, suggesting residential populations. Still later ascotton approaches physiological senescence (i.e., cut-out),the simulated densities are in excess of what is actually inthe cotton field. We view this as emigration from thesystem. Our control tactics were timed to coincide withthese periods of immigration when in-field naturalcontrols were insufficient to prevent economic loss.



Ellsworth/UA

Stages Definedby Efficacy &Safety onBeneficials

• Stage I – FullSelectivity

• Stage II – PartialSelectivity

• Stage III –SynergizedPyrethroids

Ellsworth et al. 2006

As part of our IPM program, a 3-stage chemical useplan identifies chemistry based on efficacy andselectivity attributes, with the ultimate goal ofexploiting selectivity as much as is possible. It doesnot mandate a sequence but teaches growers thatmore selective approaches will create moreeffective ecosystem services that provideregulation of all pest species.



Ellsworth/UA

A Rose is not a Rose!

• Validated selective

approach

• Natural enemy presence

• Comparative NE densities

– Counts

– Principal Response Curves

• Functional role of NEs

– Predator : Prey ratios

– Life tables, demography

– Irreplaceable mortality

Selective

Designing and labeling a product as selective or“biorational” is not sufficient to establishing itsselectivity. Because it is subject to a specificecological context, some effort must be made tovalidate the candidate approach or product in thesystem of interest. Thus, a product may be fullyselective within one environment andcatastrophically disruptive in another. Petri dish orsimilar assays without ecological context areinadequate for establishing the selectivity of asystem.

There are several ways to verify and validate anapproach as being selective.



Ellsworth/UA

Sucking Predation

Naranjo. 2001. Crop Protection 20: 835–852.

Ellsworth & Martinez-Carrillo. 2001. Crop

Protection 20: 853–869.

Naranjo, Ellsworth, Chu & Henneberry. 2002. J.

Economic Entomology 95: 682-691

Naranjo, Hagler & Ellsworth. 2003. Biocontrol

Science & Technology 13: 571-587.

Naranjo, Ellsworth & Hagler. 2004. Biological

Control 30: 52-72

Naranjo & Ellsworth. 2005. Entomologia

Experimentalis et Applicata. 116: 93-108.

Ellsworth, Palumbo, Naranjo, Dennehy, Nichols.

2006. IPM Series No. 18. University of Arizona

Cooperative Extension Bulletin, AZ1404.

Ellsworth, Fournier & Smith. 2007 (rev. 9/08).

Publ. No. AZ1183. University of Arizona.

Naranjo & Ellsworth. For Biological Control, in

review.

Naranjo & Ellsworth, Pest Management Science, in

prep.

Naranjo. 2001. Crop Protection 20: 835–852.

Ellsworth & Martinez-Carrillo. 2001. Crop

Protection 20: 853–869.

Naranjo, Ellsworth, Chu & Henneberry. 2002. J.

Economic Entomology 95: 682-691

Naranjo, Hagler & Ellsworth. 2003. Biocontrol

Science & Technology 13: 571-587.

Naranjo, Ellsworth & Hagler. 2004. Biological

Control 30: 52-72

Naranjo & Ellsworth. 2005. Entomologia

Experimentalis et Applicata. 116: 93-108.

Ellsworth, Palumbo, Naranjo, Dennehy, Nichols.

2006. IPM Series No. 18. University of Arizona

Cooperative Extension Bulletin, AZ1404.

Ellsworth, Fournier & Smith. 2007 (rev. 9/08).

Publ. No. AZ1183. University of Arizona.

Naranjo & Ellsworth. For Biological Control, in

review.

Naranjo & Ellsworth, Pest Management Science, in

prep.

General observation can establish the presence andfunction of natural enemies. In this example, wecan see two of the whitefly’s flattened nymphs onthe underside of a cotton leaf. Upon closerinspection, however, we can determine that in factthese nymphs are dead and have been evacuatedby some kind of sucking predator, probablyGeocoris or perhaps Orius.

The information and data I will share with youcomes from a series of studies carried out overmany years and published in collaboration withSteve Naranjo (USDA-ARS, ALARC) and others.



Ellsworth/UA

Life Table Set-Up

Many of the insights we have developed over theyears are the result of extensive life table studiesthat we have done in cotton. These are not easythings to do in general, but especially mid-summerin Arizona heat. However, the immobility of thenymphal stage has provided us a convenient systemwhereby we mark the locations of thousands ofinsects in both managed and unmanaged cottonsystems. Then Steve and I monitored the fate ofeach individual whitefly until death or adultemergence. From these data, we constructed lifetables that tell us what mortalities are operationaland which ones are most influential in populationregulation.



Ellsworth/UA

Thanks to Demonstration Farm

Normally, we say thanks at the end of apresentation or paper. However, I would like tothank the Maricopa Agricultural Center whichoperates a traditional research farm as well as arather unique Demonstration Farm, whereresearchers and extension specialists can docommercial-size experimentation and demonstratenew technologies for our stakeholders. We haverun replicated trials as large as 190 acres! And,routinely do assessments on large plots, one thirdto 5 acres in size. These dimensions are veryimportant when trying to develop insights intopopulation processes of mobile insects.



Ellsworth/UA

Thanks to Our Crew!

I would also like to thank the many crews I’ve hadover the years, who have assisted in all phases ofthis very difficult work. Special thanks to VirginiaBarkley, my research technician, who helps keepthe crew running smoothly.



Ellsworth/UA

Selectivity through Timing

Similar whitefly densities at 5 & 10 / leaf thresholds

0

100

200

300

400

10-Jul 17-Jul 24-Jul 31-Jul

2.5/leaf

5/leaf

10/leaf

20/leaf

ControlWhitefly-days

Naranjo, Ellsworth, Chu, Henneberry, J. Econ. Ent. 2002

**

* *

Processes and not products per se can be selectiveas well. In this example, we were working withvery broad spectrum conventional materials andapplying them according to 4 nominal thresholds.Looking at cumulative whitefly-days over time, wecan see that there is little difference between the 5& 10 adults / leaf thresholds. 20/leaf was far toohigh and gave rise to unacceptable sugar depositson lint. The 2.5/leaf regime was very aggressiveand expensive to maintain. 5/leaf is our currentthreshold for adults. However,…



Ellsworth/UA

0

100

200

10-Jul 17-Jul 24-Jul 31-Jul

2.5/leaf

5/leaf

10/leaf

20/leaf

ControlPredator-days

Selectivity through Timing

But more predators at 10 / leaf threshold

Predators most influenced by date of first spray

****

Naranjo, Ellsworth, Chu, Henneberry, J. Econ. Ent. 2002

Substantially more predators can be found in the10/leaf threshold relative to the 5/leaf threshold.In fact, in these studies, predators were mostinfluenced by the date of first spray. So a moreselective threshold would be one that serves todelay the usage of a broad-spectrum insecticide.

And even broad-spectrum insecticides can be usedin a way that increases the functionality of naturalenemies.



Ellsworth/UA

Principal Response CurveNatural Enemies to Broad Spectrum Insecticide

P < 0.01

Community response of ca.20 natural enemies

GeocorisOrius

ChrysopidsDrapetis

Lady beetlesSpiders

NabisZelus

••

•

Naranjo, Ellsworth, Hagler, Biol. Control 2004

Another way to validate a selective approach is tomeasure and analyze whole community responses.We used a multivariate, time-dependent, analyticapproach that is represented graphically inPrincipal Response Curves. In this example we cansee the green ‘U’ line representing the UTC as abaseline from which we compare other treatments.Departures from the baseline may be interpreted asdensity changes in this natural enemy community.The red arrow indicates the timing of a single, verybroad spectrum insecticide sprayed to controlLygus in a study that we did several years ago…



Ellsworth/UA

P < 0.01

Community response of ca.20 natural enemies

Season-long

effects

Principal Response CurveNatural Enemies to Broad Spectrum Insecticide

Naranjo, Ellsworth, Hagler, Biol. Control 2004

…What we see is a dramatic and immediatelowering of the density of these natural enemies incomparison to the UTC. What is more sobering isthe duration and significance of this effect, all theway out to 7 weeks post-treatment. These season-long effects have grave consequences in the controlof many other primary and secondary pests, as wellas Lygus. So having potentially selective options toreduce the risks of natural enemy destruction isquite important to us.



Ellsworth/UA

Generalist Predators

P. seriatusM. celer

G. pallensO. tristicolor

L. hesperusG. punctipes

D. nr. divergS. albofasciat

N. alternatusC. carnea

D. reticulataZ. renardii

C. vittatusH. convergens

SalticidaeSinea spp.

Other CoccinellOther Aranidae

R. forticornisAnthicidae

-0.5

0

0.5

1

1.5

2

2.5

Naranjo, Hagler, Ellsworth, Bio. Sci. Technol. 2003

In this PRC, we were working on commercialacreage and could not set-up an UTC. So thebaseline in this case is conventional, broad-spectrum chemistry as was common in the early tomid-1990’s. The IGRs, (P)yriproxyfen and(B)uprofezin, were generally supporting morenatural enemies than the conventional control.Generalist predators often drive these relationshipsas seen here with Misumenops celer, a commoncrab spider. As seen in the accompanying specieswts table, species with weights greater than 0.5 areconsidered most influential and most reflective ofthe PRC shown. The large crash seen in the middleof the curve is attributable to two things. Majormonsoon-associated storms, and a broad spectrumLygus spray. Note one spray saved in this study.



Ellsworth/UA

L. hesperusO. tristicolor

G. punctipesC. carnea

P. seriatusDrapetis sp.

M. celerZ. renardii

Other AraneidaN. alternatus

S. albofasciatSinea spp.

C. vittatusSalticidae

H. convergensD. reticulata

G. pallensOther Coccinell

R. forticornisAnthicidae

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

Naranjo, Ellsworth, Hagler, Bio. Control 2004

Orius & GeocorisOrius & Geocoris

In subsequent years, we ran very large scalereplicated studies that included an untreated check,the orange baseline. Once again, however, the(C)onventional chemistry suppressed NEs for aperiod that extended almost the entire season. TheIGRs, on the other hand, rarely departedsignificantly from the UTC line. Sucking predatorsare very important in our system and Orius andGeocoris drive this particular PRC.

Again one spray saved relative to the conventionalregime.



Ellsworth/UA

Drapetis sp.L. hesperus

P. seriatusO. tristicolor

M. celerG. punctipes

C. carneaAnthicidae

C. vittatusG. pallens

S. albofasciatR. forticornis

SalticidaeH. convergens

D. reticulataN. alternatus

Z. renardiiOther Araneida

Other CoccinellSinea spp.

-0.5

0

0.5

1

1.5

2

2.5

3

3.5


WhiteflySpecialists

Drapetis

In another example, an unusual predaceousEmpidid fly, Drapetis, drove the overall PRC. Thisadult fly, while technically not restricted to whiteflyprey, does seem to specialize on feeding on adultwhiteflies. A related species is present in Israelicotton where whiteflies are also a key pest.

Each time, the two IGRs selectively control thewhiteflies while conserving the NE complex.

1998 was an unusual year in that no matter whatwas sprayed, whitefly populations collapses and nomore spraying was needed, even in theconventional regime.



Ellsworth/UA

ChewingPredation

M. celerG. punctipes

L. hesperusO. tristicolor

Drapetis sp.C. carnea

Other CoccinellOther Araneida

C. vittatusR. forticornis

D. reticulataP. seriatus

N. alternatusSalticidae

Z. renardiiSinea spp.

G. pallensH. convergens

S. albofasciatAnthicidae

-0.5

0

0.5

1

1.5

2

2.5


Evidence of chewing predation is rarely seen because itresults in the complete removal of the nymphal or eggstage whitefly, unlike what you can see in this picture,where a partial cadaver was left by a predator. WhileHippodamia is often present in cottonfields early in theseason, Collops spp. beetles are far more common andmore likely to be influential on whitefly dynamics, alongwith some smaller coccinellids. In this example just oneIGR spray was needed to accomplish season longcontrol of whiteflies, and 3 conventional sprays wereneeded to accomplish similar levels of control.

Note, too, that we often see an apparent decline in theIGR lines relative to the UTC. We believe this reflectssome weakly density-dependent effects of their beingso many fewer whitefly prey to support predators.



Food Web in Cotton

Gossypium hirsutum

Bemisia

Zelus spp.Sinea spp.

Coccinellids

SalticidsClubionids Thomisids

Drapetis sp.

Chrysoperla spp.Collops spp. Nabis spp.

Orius tristicolor

Encarsia spp. Eretmocerus spp.

Geocoris spp.

The idea that different species dominate the PRC indifferent years or locations in AZ cotton is aremarkable testament to the complexity of the foodweb. Certain conditions may favor certain pathwaysin certain years and other pathways in other years.Yet the same, generally, level of natural mortality isexpressed.



Food Web in Cotton

Gossypium hirsutum

Bemisia


Coccinellids


Drapetis sp.


Orius tristicolor


Geocoris spp.

Four predators dominated the PRC in this year.



Food Web in Cotton

Gossypium hirsutum

Bemisia


Coccinellids


Drapetis sp.


Orius tristicolor


Geocoris spp.

Three species in this year.



Food Web in Cotton

Gossypium hirsutum

Bemisia


Coccinellids


Drapetis sp.


Orius tristicolor


Geocoris spp.

And a different set of 3 species in this year.



Food Web in Cotton

Gossypium hirsutum

Bemisia


Coccinellids


Drapetis sp.


Orius tristicolor


Geocoris spp.

And 5 species dominated the PRC this year.

Other analyses are necessary to better understandhow these NEs are functioning.



Ellsworth/UANaranjo, Ellsworth, Hagler, Bio. Control 2004

Predators increase &keep pace

One way to do this is to examine Predator:Preyratios. In this example, all predators captured in 50sweeps compared to all whiteflies per leaf incotton. Here we see that predator numbersincrease and stay level relative to prey numbers,which are increasing through this time period.

Recall that this “Control” is producing out-of-control whitefly populations.



Ellsworth/UANaranjo, Ellsworth, Hagler, Bio. Control 2004

No improvement inbalance

Conventional sprays served to lower prey densities,but predator densities as well. Thus, there is noimprovement in the balance.

Recall again that whiteflies are in fact well-controlled by conventional chemistry but required 3sprays to do so in this example.



Ellsworth/UA

* * *


IGRs improve balancesignificantly

IGRs on the other hand not only reduce preynumbers, they conserve existing predator numbersand create a more favorable balance of predators toprey resulting in a more efficient control systemthat creates collateral benefits in regulation ofother pests in the system. Only 1 IGR spray wasneeded.

So the question is how are we changing thesurvivorship of whiteflies when we apply IGRs…



Ellsworth/UA

“The ideal material is not one thateliminates all individuals of the pestspecies….[It] is the one that shifts

the balance back in favor of thenatural enemies”

Stern et al. 1959

But before we answer that question, we must tipour hat once again to Stern and colleagues…

They saw envisioned an ideal material that we onlygained commercial access to some 37 years later.Our Section 18 emergency exemptions forpyriproxyfen and buprofezin in Arizona cotton werethe first uses of these materials in U.S. agriculturein 1996.

So what does whitefly survivorship look like whenwe apply IGRs…



Ellsworth/UA

Pro

po

rtio

n S

urv

ivin

g

0.0

0.2

0.4

0.6

0.8

1.0

Egg N1 N2 N3 N4 Adult

0.00

0.05

0.10

Average Survivorship inCotton

Untreated

Insecticides

Naranjo & Ellsworth, Entomologia Exp. et Appl. 2005

Steve and I examined 14 summer generations ofwhiteflies in cotton and constructed life tables. Inuntreated systems, whiteflies survived to adult atwhat appear to be very low rates. Rates that beliethe explosive potential of this pest.

When we compare this to systems managed withthese selective insecticides, we see what appears tobe only a subtly different outcome.

There is a difference in survivorship: the yellow linerepresents an out-of-control growing population,while the purple represents a well-managed systemwith collapsing populations. Thus, we are trying toleverage, on average, only about a 4% absolute orirreplaceable change in survivorship by usinginsecticides.



Ellsworth/UA

Irreplaceable MortalityUntreated Cotton

0.0

0.1

0.2

0.3

0.4

PredationParasitism

MissingInviable

Other

Naranjo & Ellsworth, Entomologia Exp. et Appl. 2005

“In many agricultural areas,pest control provided by naturalenemies has been replaced by

pesticides...”

Millennium Ecosystem Assessment, 2005

You can only die once! So even though one mortalityfactor can act to kill a whitefly like pyriproxyfen killing alarge nymph, a predator can come along & then feeddirectly on the newly dead cadaver. Math allows us toestimate which factors are more “irreplaceable” orindispensible in untreated cotton & thus infer which onesare most important in controlling the insect populations.For whiteflies in cotton, predation is by far the mostimportant mortality factor. This is WHY selectivity of theIGRs is so key. The remaining factors are not nearly asimportant. Incidentally, despite major changes, if not,wholesale species replacements over the last decade,parasitoids exert very little irreplaceable mortality. Here,too, a portion of ‘missing’ is due to chewing predation.This is where we need selectivity in chemistry. This cuts tothe heart of the criticism made in the recent globalecosystem assessment.



Ellsworth/UA

Irreplaceable Mortality


1st Generation Post

We examined patterns of irreplaceable mortality inselective vs. conventional systems. The two majorsources of mortality are “insecticide” andpredation. No insecticide-related mortality wasmeasured in the UTC, but similar levels for eachcompound used in the first generation exposed tothe sprays. Predation, however, was significantlyhigher in the UTC. Even though predation is presentin the IGR regimes, it is less irreplaceable becauseof the insecticidal action of the IGRs. Recall thatyou can only die once. IGRs are most certainlykilling whiteflies; however, predators are alsofeeding on these whiteflies.

If we advance our time step to the next generation,ca. 3-6 weeks later…



Ellsworth/UA

Irreplaceable Mortality


2nd Generation Post

Looking at the next time course, i.e., the 2ndgeneration after initiating sprays, we see that ratesof insecticidal mortality are still present whereinsecticides are used, but lower than before.Residues are diminished. Irreplaceable mortalitydue to predation, however, grows substantially inthe IGR regimes, but much less so in theconventional regime. These levels of irreplaceablemortality in the IGR regime are very similar to whatcan be seen in the UTC.

Thus, the bioresidual effect is starting to exertinfluence over the population, because predators inparticular were selectively conserved in the IGRsystem.



Ellsworth/UA

Natural Enemies ExcludedNatural Enemies Excluded

Broad-spectrumLygus sprays

releasewhiteflies

Broad-spectrumLygus sprays

releasewhiteflies

Convincing an industry that used to spray 10-15times per season with broad-spectrum chemistrythat natural enemies can be part of the fabric oftheir control system is a difficult. Pictures do tell astory, however.

Peter Asiimwe, our current graduate student, istrying to understand the relative contribution ofNEs and irrigation to the control dynamics ofBemisia. Last year, we had plots where NEs werechemically excluded by using a common Lygusinsecticide. These broad-spectrum sprays releasedwhiteflies from the natural control possible in the rthand figure. The result was very sticky and sootycotton. The left side was never sprayed at all.



Ellsworth/UA

Natural enemies excluded

Natural enemies excluded

19% yield loss

7% yield loss

Biological Defoliation

Regardless of irrigation regime, there were majorlosses to whiteflies where NEs were excluded.These paired pictures were shot on the same day(two weeks after the ones shown on the previousslide) and show cotton that was biologicallydefoliated by this sucking pest. The cotton on theleft was never sprayed for any pest and also hadcommercially unacceptable whitefly levels but atmuch lower densities than in the exclusion plots.

This example stresses the interactions of ourcontrol systems for Lygus and whiteflies. That is, nomatter how selective our control system is forwhiteflies, if growers are spraying for Lygus orother pests with broad-spectrum materials,selective advantages may be lost.



Ellsworth/UA

System Compatibility

LygusIPM

WhiteflyIPM

Thus, our whitefly IPM system needs to becomplementary with our other pest managementsystems…

Not surprisingly, the same key set of elements arenecessary for management of Lygus. For decades,we have had “effective” control chemistry forLygus, but no selective or biorational options untilvery recently.



Ellsworth/UA

“Where prophylactic treatments are provedto be necessary for a perennial pest,

selective materials must be developed andutilized to foster biological control both of

other pests and of the pest of directconcern at other times.”

Stern et al. 1959

Once again, these ideas are not new ones. Sternand colleagues wrote about this as well…



Ellsworth/UA

Lygus hesperus

• Native to N. America

• No. 1 yield limitingpest for last decade

• Attacks squares,causes shed

Lygus bugs have become our number one pest sinceabout 1997, ever since more selective componentsof our system became available, specifically Btcotton for PBW control and the IGRs for whiteflycontrol. This mirid attacks squares and causes themto shed. Compatibility and integration of controlswith this pest are very important.



Ellsworth/UA

O

O

OO

O O

OO

! ! ! ! ! ! ! !

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

14-Jul 21-Jul 28-Jul 4-Aug 11-Aug18-Aug25-Aug 1-Sep 8-Sep

Ca

no

nic

al

Co

eff

icie

nt

* * * * * * *

Principal Response CurveNatural Enemies to Orthene v. Carbine or Metaflumizone

06F25NED

Whitefly outbreak!

Ellsworth & Naranjo, unpubl.

In our 2006 study, we did repeated (every otherweek) sprays (for a total of 3) of Lygus controlchemicals. First, we can see that Orthene(acephate) predictably lowers the densities of thenatural enemy community very significantly and forthe duration of the season. Interestingly, 2006 wasa historic low in whitefly pressure. Yet, shortly afterthe 2nd spray, we noted a severe anduncontrollable whitefly outbreak in these largeplots (1/3 A) of Orthene. Effectively, we haddamaged the natural enemy community thatotherwise maintains whiteflies at very lowdensities. The UTC and candidate compounds hadno whitefly resurgences.



Ellsworth/UA

O

O

OO

O O

OO

! ! ! ! ! ! ! !

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3


Ca

no

nic

al

Co

eff

icie

nt

* * * * * * *

Principal Response CurveNatural Enemies to Orthene v. Carbine or Metaflumizone

06F25NED

MM

M

M

MM

MM

M M

MM

M M

M

M

C CC

C C C

C

C

O

O

OO

O O

OO

! ! ! ! ! ! ! !

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3


Ca

no

nic

al

Co

eff

icie

nt

MBAS320WUI

0.25

MBAS320OOI

0.25

CCarbine

0.088

OOrthene

1.0

! UTC

Sprays


Carbine or flonicamid (orange line) showed nosignificant declines in the NE community.Metaflumizone at its maximum rate and for twodifferent formulations (blue lines) also had noimpact on the NE community.

And neither compound suffered from whiteflyresurgence.

So we are on our way to development of the lastbiorational or selective building block of our cottonIPM system. Carbine has been registered in AZsince late 2006 (first major commercial uses in2007).



Ellsworth/UA

Species Wts.

• Spiders & predaceoushemiptera = drivers

• Larval chrysopids &Drapetis = againsttrend (WF ‘specialists’)

G. punct.Spiders

Misum.Nabis

ZelusSalticids

Dictyna.Orius

G. pall.Rhinacloa

NotoxusSinea

C-7 Ants

CollopsHymenop.

Other cocc.Spano.

Hippo.Drapetis

Larval Chrys.

-2

-1

0

1

2

3

4

N E U T R A L

…Strong positive (>0.5) weights indicate speciesthat tracked very closely the relationship depictedpreviously. Strong negative (<0.5) weights indicateindividual species that actually exhibit a reversal oftrend shown. In this experiment, we saw thatspiders and predaceous hemiptera were driving thesystem. That is they were the subject of the largedecline in the Orthene plots yet conserved in theothers. Interestingly, the Orthene plots had anabundance of larval lacewings and Drapetis (anempidid, predaceous fly), each in response to thewhitefly resurgence; I.e., they followed the pest!



05F2L

Ecological Context is Important


Ecological context is critical to understanding theselective potential of any approach. Novaluron,ostensibly an insect growth regulator, is actuallyquite a broad spectrum chitin inhibitor. In somesystems, it may perform selectively. However, bythese measures and in our ecological context (theAZ cotton system), it is no more selective thanacephate, whether used alone or in combinationtwo to four times. [Novaluron1* indicates that onlythis trt received the 3rd spray.]

Novaluron is registered as Diamond in AZ but neverrecommended for whitefly or Lygus control.Additionally, pyriproxyfen has been disruptive insome other systems, especially via the destructionof some coccinellid predators in some citrussystems (S. Africa & California).



Ellsworth/UA

“…failure to recognize that control ofarthropod populations is a complex

ecological problem….leads to the error ofimposing insecticides on the ecosystem,

rather than fitting them into it.”

Stern et al. 1959

Stern saw this ecological context and wrote withgreat clarity:

Probably every agricultural system has witnessed aperiod where insecticides were imposed on thesystem rather than fitted to it.



Ellsworth/UA

Levels of Integration in IPM(from Kogan 1998, 2001)

• Level I – “Species / population level integration”

– The integration of control methods for single species orspecies complexes

• Level II – “Community level integration”

– The integration of the impacts of multiple pestcategories on the crop and the methods for their control

• Level III – “Ecosystem level integration”– The integration of multiple pest impacts and the

methods for their control within the context of the wholecropping system

IPM exists at different levels of integration. Wewish to raise the level of integration to a pointultimately where the entire ecosystem isconsidered. Level I integration acts at the speciesor population scale; Level II at the communityscale; and Level III integration operates at theecosystem scale, the level we wish to advancescience and understanding.



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 by water intoa very complex agroecosystem. AZ’s year round growingseason provides for a sequence of crop plants, wintervegetables like broccoli, lettuce, other cole crops, springmelons (esp. cantaloupes), summer cotton, and fallmelons. These crop islands provide for perfect habitat forwhiteflies, and our focus was on the intercropinteractions that were possible with this pest and thatdemanded a high level of integration in our IPMprograms. I could describe for you the landmark cross-commodity interactions we had, but instead will justshare piece of evidence that re-enforces areinterdependence and also relates to the idea that Sternsuggested “insecticides” are not permanent features ofour system. But perhaps there effects have greaterconsequence that once believed.

Photo credit: JCP



Ellsworth/UAPalumbo/UA

Areawide Pressure

Admire 1st used

Widespread

use of Admire

IGRs in cotton

introduced

Dome Valley

Palumbo, unpubl. data

A historic example of cross-commodity (orecosystem level) interactions: John Palumboestablished untreated blocks of lettuce withincommercially-treated fields with soil-appliedimidacloprid. In this chart, we see whitefly levelsstarting in 1993 when Admire was 1st used.Pressure was extreme as seen in the UTC green bar,but Admire did an excellent job at reducing thesenumbers. In 1994-1995, we see a period ofwidespread use of Admire and numbers werereduced in the UTC by nearly an order ofmagnitude. In 1996 through today, we enter aperiod where the IGRs were first registered andused in AZ cotton and used on a wide-scale. Theresult is another magnitude lowering in the overallwhitefly density, and what we think of as area-widesuppression of whitefly populations.

Photo credit: JCP



Ellsworth/UA

IntegrationBt cotton for

Pink Bollworm

Selective Controls

for Lygus

Whiteflies in

Vegetables

Whiteflies in

Melons

Integration can be thought of in at least twodimensions. Again, considering Bemisia in cotton asthe central focus of our attention, we can see thatvertically, within a crop, we must integrate ourmanagement programs with advances in controllingother cotton pests, particularly selective ones. Atthe same time, whiteflies in cotton are directlylinked to whiteflies across the entire landscape, inspace and in time, from vegetables to melons.



Ellsworth/UA

USDA-CSREES, Risk Avoidance & Mitigation Program(RAMP)

Developing and implementing field and landscape levelreduced-risk management strategies for Lygus in

Western cropping systems

So I’d like to talk about how we are trying toadvance our understanding of Lygus movement andmanagement across the entire agroecosystem ofthe West and integrate that with existing IPMprograms. We are so large that we’ve never hadeveryone in one spot at one time, but this is abouthalf of the overall team (including collaborators).Yves Carriere, Al Fournier (UA, adjunct), SteveNaranjo (USDA, adjunct), and Peter Ellsworth fromentomology are shown. As part of our project, weorganized an international Lygus symposium.

The project team. Missing PIs: Larry Godfrey (UC-Davis); David Kerns (Texas A&M); Jay Rosenheim(UC-Davis); Scott Bundy (NMSU).

Picture is from the 2nd International Lygus Symposium held atAsilomar Conference Center, Pacific Grove, CA, 15-19 April 2007,and sponsored in part by the APMC and the USDA-RAMP grant.



Ellsworth/UA

IndividualMovement(flight assays)

Obj. 3C

Population-Level Movement

(Mark-recapture)Obj. 3C

Descriptive spatio-temporal

Population Dynamics

(GPS/GIS)

Obj. 3A

Mechanistic Spatio-Temporal

Population Dynamics

(Simulation Model)

Obj. 3B

Farmscape

Host Management

(Alfalfa/Boswell)

Obj. 3C, 4B, 4C

Spatio-Temporal Economics

(Grower Gaming Simulation)

Obj. 3B, 4C

LandscapeLevel

This large RAMP has studies operating or havingimpact on a Landscape or Farmscape level, startingwith studies of individual behavior on up throughprogressively larger spatial scales.

A conceptual flow-diagram of landscape-levelRAMP components. Arrows depict flow ofinformation. Within the Landscape-Level domainthe size of the ovals indicate the spatial context ofthat element from very localized (e.g., individualmovement) to regional and multi-state (e.g. spatio-temporal economics).

I wish to focus on the descriptive spatio-temporalstudies we are embarked upon currently.



Ellsworth/UA

Carriere

(UA)

Palumbo(UA)

Ellsworth,Fournier (UA)

Naranjo,

Blackmer,Hagler (USDA)

Parajulee(TX A&M)

Bundy

(NMSU)

Goodell

(UC-IPM)

Godfrey,

Rosenheim(UC-Davis)

RAMP Team Collaborators

Corbett (CorbettLearning)

Dutilleul (McGill)Hutmacher (UC-Davis)

Jimenez (UC-CE)Kerns (TX A&M)Molinar (UC-CE)Mueller (UC-CE)

Spurgeon (USDA)Tronstad (UA)

Two years ago we received a grant from the USDA-Risk Avoidance and Mitigation Program (RAMP) forthe purpose of developing information that willhelp growers more efficiently manage Lygus overthe entire western landscape. This is a largecollaboration that we at the University of Arizonaare leading.

There are many projects in this grant designed tohelp us understand Lygus management andmovement across the landscape. The large studythat I wish to describe now is taking place in thecentral valley of California under Dr. Goodell’sleadership, in west Texas under Dr. Parajulee’sleadership, and in central Arizona under myleadership.



Ellsworth/UA

Crop Placement

Right at the heart of our IPM strategy is “CropPlacement”. Crop placement is central to itsavailability to other pests. By strategicallyconsidering how we arrange and place our cropsboth in space and time, we can help to deny ourcrops as a resource for pest insects.

The problem until now is that we have only verylimited information on how to strategically arrangeour crops to prevent or minimize damage frominsect pests.



Ellsworth/UA

Regional Ecology Project

• Map all fields in the area

• Identify all crops grown

• Select focal fields for sampling Lygus weekly

• Calculate density of each habitat in rings

around focal field

• Estimate relationship between different

habitats and abundance of Lygus in focal fields

So we have developed an approach using newmapping and analytical technologies that will allowus to ultimately advise growers how to minimizedamaging Lygus populations through cropplacement.

…



Ellsworth/UA

Arizona Site: Central AZ

Our area of study is located in the greatestconcentration of cotton in the state in centralArizona, Pinal County.

This map shows about 54 randomly selected cottonfields on which we focus our study of Lygusdynamics.



Ellsworth/UA

Influence of crops at differentspatial scales

The objective of this project is to map out theagricultural landscape and measure the influence ofdifferent crops on Lygus dynamics through thesystem at various spatial scales.

The goal would be to identify patterns in ourecosystem that can be exploited for pestmanagement.

Analyses can take place at any spatial interval overany scale. In our case we are looking at 0.75 kmintervals out to 3 km.

2007FF#27



Ellsworth/UA

Influence of New Crops:Guayule

Guayule is a desert-adapted, commercial crop thatis new to us and expanding with a projectedwestern acreage of 250,000 A one day spanning W.TX to the SJV of CA. It is grown as a perennial andis a known reproductive host for Lygus. It wasgrown on about 4,000 A in AZ in 2007 and 2,000 Ain 2008.

Is it a source, a sink, or both depending on season?

We just don’t know at this point, but this exampleshows a focal cotton field adjacent to a 40A field ofguayule.

2007FF#27



Ellsworth/UA

Grower Educational Products

Bulletins / Circulars

Publications

Websites

Obj. 1,2,3,4B,4C

Grower Educational Processes

Interactive Training Gaming Model

Guidelines Development

Growers Meetings

Field Days

Obj. 1,2,3,4B,4C

Engagement

Grower Participatory Research

On-Farm Demonstrations

International / Scientific Exchange

Program Evaluation

Obj. 1,2,3,4

Outreach

Our RAMP also has innovative outreach activitiesplanned including the development of a gametraining simulation model that will be used to helpgrowers learn about the benefits of cooperation,specifically in terms of crop placement and risks tothe community of Lygus damage.

Outreach activities bridge field- and landscape-levelcomponents and provide critical feedback to ensurethat research is relevant and provides practicalsolutions to risk mitigation while also fostering animproved fundamental understanding of pestimpact, behavior, biology, and ecology at multiplespatial scales.



Ellsworth/UA

Improving PestManagement

• Help growers avoid pest problems

• Manage sources & sinks for Lygus, whiteflies &natural enemies

• Benefits to all growers, but especially thosethat manage large areas or are able tocooperate with neighbors

• Farm- to Community-scale decisions

– Better management of crop & non-crop sources

– Crop Placement to lower community-wide risks ofpest damage in all crops AND to enhance colonizationby key natural enemies

Our goal is to help growers avoid damaging Lyguspopulations right from the start. We hope to do thisby giving them specific advice on how to managethe plantings of their many crops. By knowing whatcrop placements lead to more “sinks” for Lygusthan “sources”, a grower can become moreprofitable while reducing risks to the human healthand the environment. This work is being extendedto whitefly spatial dynamics through an NRI led byYves Carriere, and to natural enemies. Our hope iswe will develop a useful understanding of howpests and natural enemies colonize and movethrough an agroecosystem. Any grower can benefitbut especially those that control a larger part of thelandscape. Ultimately, we wish to lower the generalequilibrium position and overall community-widerisk.



Ellsworth/UA

Pest Damage

(Yield/Pest Density)

Obj. 1A,B

Reduce-risk Insecticides

(Efficacy Testing)

Obj. 2A

Threshold Development

& Refinement

(Yield/Pest Density)

Obj. 1A,B

Natural Enemy

Conservation

(Selectivity Testing)

Obj. 2B

FieldLevel

Which brings us back to field level processes, wherewe are working to develop and refine thresholds,and develop selective options for Lygus control, thevery things that Stern et al. said are integral to theICC.

Field-level components feed into the landscape-level by governing localized population dynamicsand management practices that ultimatelydetermine population processes and managementstrategies within larger landscape contexts.Feedback occurs when landscape-level processesresult in lowering of Lygus risks such that field-level practices become more functional (e.g.,natural enemy conservation & biological control).



Ellsworth/UA

'90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '080

2

4

6

8

10

12

14

Fo

lia

r S

pra

y I

nte

nsit

y

Whitefly Pink bollworm Lygus bugs Other

Statewide Cotton Sprays

Need for IPM Strategy!

The need was great; the situation dire. Cottongrowers were spraying 5-15 times to control anarray of pests. Whitefly, Pink Bollworm, and Lygusbugs are our 3 key pests of cotton in AZ.

There was a critical need for an IPM strategy,especially after the whitefly outbreak of 1995precipitated in part by a resistance episode.

Statewide average cotton foliar insecticide sprayintensity by year and insect pest (Ellsworth et al.,2008).



Ellsworth/UA

'90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '080

2

4

6

8

10

12

14

Fo

lia

r S

pra

y I

nte

nsit

y


Cotton IPM Saves Millions $

$201,000,000 saved costs & yield loss

IGRs, Bt cotton & AZ IPM plan

Zero grower sprays for PBW


The results have been striking. A watershed ofchange occurred in 1996 with the introduction ofvery safe and selective Insect Growth Regulatorsfor whitefly control, and transgenic Bt cotton, alongwith an IPM plan for whitefly management.

More recently, state agencies began PBWeradication in 2006. For the first time since themid-1960’s, AZ growers statewide did not spray atall for PBW! Bt cotton is grown on 98.25% of theacreage. And whiteflies have faded from memory asa severe and unmanageable pest.

[Carbine for Lygus control first adopted in 2007.]

The credit we take for any part of this is sharedwith many, many others, but the result has beenover $200M saved cumulatively since 1996.



Ellsworth/UA

Lowest Costs in 30 years(inflation-adjusted to 2008 dollars)

Lygus: -35%

PBW: -89%

Whitefly: -71%

& Fewer Sprays& Fewer Sprays

in last 7 yearsin last 7 years


Growers spent less on insecticides in 2007 than atany other time on record (30 years). Comparing thelast 7 years to the 6 preceding the 1996introduction of our new IPM plan, growers havesprayed far less than before. The average growernow sprays once or twice, with compounds that arerelatively safe, far safer than anything used in thepast, to control all insect / arthropod pests season-long. Cotton is grown from March to October.

Statewide average cotton foliar insecticide sprayintensity by year and insect pest (Ellsworth et al.,2008).



Ellsworth/UA

'90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07 '080

2

4

6

8

10

12

14

Fo

lia

r S

pra

y I

nte

nsit

y


Health & Environment

1.7M lbs reduction in insecticide

use

Lowest usage in30 yrs!


The benefits extend to health and safety of workerson farm and the greater environment at large.Comparing our 30-year high in 1995 to our lowestusage in 2006, growers used 1.7 million lbs lessinsecticide!



Ellsworth/UA

Blo

om

s p

er

Are

a

Heat Units After Planting (86° / 55°F)

PrimaryFruitingCycle

‘Top’crop

cut-out

Selectivity Enables CBCBt CottonEradication

Stage I: Fully SelectiveStage II: Partially

Stage III: Broad

Selective: Carbine (BAS320)

Broad Spectrum:Orthene, Vydate

Broad Spectrum Insecticides

Secondary pests heldunder natural control

“These intermittently

destructive populations mustbe reduced in a manner that

permits biological controlwhich prevailed before or

prevails elsewhere to takeover again.”

Stern et al. 1959

Our system breaks down to 3 key pests and a largearray of secondary pests that never becomesignificant, IF disruptions of natural controls do notoccur. For PBW, Bt cotton is the ultimatebiorational, and now with eradication, broadspectrum insecticides for its control are fadingcompletely from our system. For whitefly, we haveorganized our insecticides into 3-stages based onselectivity, deferring all broad-spectrum inputsuntil the end of the season, if needed at all. ForLygus, we have one selective insecticide,flonicamid, with another soon to become available.Cotton IPM in AZ has become an exceptionally well-developed and selective system where conservationbiological control is firmly established as a keyelement. “Chemical control augments biologicalcontrol.” Stern et al. saw it; Stern et al. predicted it.



Photo credit: J.Silvertooth

Ellsworth/UA

Arizona Pest Management CenterPest Management Alternatives Program

Extension IPM Special ProjectsWestern Regional IPM Program

Western IPM CenterUSDA-ARS

National Pesticide Impact Assessment ProgramCotton Incorporated / Arizona Cotton Growers Association

Agrochemical Industry

Arizona Pest Management CenterArizona Pest Management CenterPest Management Alternatives ProgramPest Management Alternatives Program

Extension IPM Special ProjectsExtension IPM Special ProjectsWestern Regional IPM ProgramWestern Regional IPM Program

Western IPM CenterWestern IPM CenterUSDA-ARSUSDA-ARS

National Pesticide Impact Assessment ProgramNational Pesticide Impact Assessment ProgramCotton Incorporated / Arizona Cotton Growers AssociationCotton Incorporated / Arizona Cotton Growers Association

Agrochemical IndustryAgrochemical Industry

The program developed and presented here wassupported by a massive research and extensioneffort that was funded through many competitivegrants and gifts from sponsors to which we givethanks. Special thanks to co-author, Steve Naranjo.

The Arizona Pest Management Center (APMC) aspart of its function maintains a website, the ArizonaCrop Information Site (ACIS), which houses all cropproduction and protection information for our lowdesert crops, including a PDF version of this andrelated presentations for those interested inreviewing its content (cals.arizona.edu/crops).

The University of Arizona IPM Program is managedby the APMC, which also maintains anorganizational website at cals.arizona.edu/apmc

Documents

Bemisia tabaci, Biotype B Integrated Control · 2009. 5. 4. · DAG