National Center for Food and Ag. PolicyNational Center for Food and Ag. Policy

Washington, DCWashington, DC

The Benefits of Agrochemical Research: The Benefits of Agrochemical Research: Case Study of ImidaclopridCase Study of Imidacloprid

Sujatha Sankula & Leonard GianessiSujatha Sankula & Leonard Gianessi

Agrochemical categoriesAgrochemical categories

Herbicides (47%)Insecticides (29%)Fungicides (18%)

Fumigants & growth regulators (6%)

Agrochemicals are necessary to…Agrochemicals are necessary to…

Prevent yield losses Ensure quality Make crop production easier & cheaper

Crop yield response to agrochemicalsCrop yield response to agrochemicals

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Corn Soybean Potato Wheat Cotton Rice

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Without agrochemical use; With agrochemical use

Area farmed globally for food Area farmed globally for food production in 2000production in 2000

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With agrochemicals Without agrochemicals

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lion

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Global value of agrochemicals Global value of agrochemicals in 1998in 1998

$31.25 billion (crop uses)

$10.5 billion (non-crop uses)

Worldwide crop protection markets Worldwide crop protection markets in 2001in 2001

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Sale

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Goal of aGoal of agrochemical researchgrochemical research

To discover, develop, and understand new products for the safe and effective pest control and to maximize food production

Agrochemical discovery & development Agrochemical discovery & development programs are driven by:programs are driven by:

Population growth Food and health needs Pest resistance issues Safety considerations Economic incentives Replacements and phase-outs

Recent setbacks to agrochemical Recent setbacks to agrochemical discovery programs:discovery programs:

Fewer players Large investments Great risks High stakes Economics Higher standards of potency and safety

Insecticide categoriesInsecticide categories

Organic (eg. DDT, chlorpyriphos)Botanicals (eg. pyrethrum, nicotine)

Inorganic (eg. boric acid, sulfur)

Market dominance of commercial Market dominance of commercial insecticide categoriesinsecticide categories

CategoryCategory ##

InorganicsInorganics 8 8

BotanicalBotanical 5 5

Synthetic organicsSynthetic organics 192 192

Major insecticide classes by Major insecticide classes by importance as of 1995importance as of 1995

Class Class ~ Entry year~ Entry year Market valueMarket value

(%) (%)

Chlorinated hydrocarbonsChlorinated hydrocarbons 19471947 5 5

OrganophosphatesOrganophosphates 19651965 34 34

MethylcarbamatesMethylcarbamates 19691969 20 20

PyrethroidsPyrethroids 19791979 23 23

BenzoylureasBenzoylureas 19831983 5 5

Others Others 19821982 8 8

Human toxicity and insect resistance to the first Human toxicity and insect resistance to the first generation neuro-active insecticides such as generation neuro-active insecticides such as carbamates and OPs led to the search for new carbamates and OPs led to the search for new agrochemicalsagrochemicals

Significant discovery - ImidaclopridSignificant discovery - Imidacloprid

ImidaclopridImidacloprid

Classification: Chloronicotinyl

First registered insecticide in its class Year of registration in US: 1995

World sales of top selling World sales of top selling pesticides in 2001pesticides in 2001

Glyphosate $2.4 billion

Imidacloprid $540 million

Source: PANUPS 2002

Structural comparison of Structural comparison of nicotine and imidaclopridnicotine and imidacloprid

Characteristics of imidaclopridCharacteristics of imidacloprid

Novel mode of actionBroad spectrum of activityFavorable environment fate

Mode of action of imidaclopridMode of action of imidacloprid

Binds to nerve receptors called nicotinic acetylcholine receptors (nAChRs), interferes interferes with the transmission of stimuli in the insect with the transmission of stimuli in the insect nervous system leading to the accumulation nervous system leading to the accumulation of acetylcholine resulting in paralysis.of acetylcholine resulting in paralysis.

Site of action is different than other insecticides Site of action is different than other insecticides to which insects developed resistance.to which insects developed resistance.

Low toxicity to vertebrates due to low binding to nACh receptors.

Imidacloprid provides a broad Imidacloprid provides a broad spectrum of activity against:spectrum of activity against:

Sucking insects (leaf and plant hoppers, aphids, thrips, whiteflies, scales, and plant bugs)

Some coleopteran insects (CPB, leaf beetles)

Select lepidopteran and dipteran insects

No activity on mites and nematodes

Imidacloprid has both contact and systemic Imidacloprid has both contact and systemic action.action.

Imidacloprid can be applied as a soil, seed, Imidacloprid can be applied as a soil, seed, or foliar treatment.or foliar treatment.

Readily absorbed by plant roots and transmitted through xylem.

Effective at low rates than conventional insecticides (0.33 lb versus 1-2 lb of OPs)

Trade names of imidaclopridTrade names of imidacloprid

Gaucho (seed treatment)Admire (soil applied)Provado (foliar)

Use range of imidaclopridUse range of imidacloprid

Potato AppleTomato GrapeBroccoli CitrusLettuce CornSugarbeet HopsCotton Rice

Tobacco

Impacts of imidacloprid on US Impacts of imidacloprid on US crop productioncrop production

Silverleaf whitefly

First discovered in 1986 in FL

Widespread damage in 1991 in CA and AZ

Reduction in planted crop acreage

Yield and quality losses; transmits viruses (ToMoV and YLCLV)

Silverleaf whitefly is a billion dollar pest

Primary hosts of silverleaf whitefly

BroccoliCauliflowerCabbageLettuceMelonsCucumbersTomatoesCotton

Silverleaf whitefly management

Three classes of effective insecticides (pyrethroids, OPs, & chlorinated hydrocarbons)

Most common combination: bifenthrin + endosulfan (2-3) fb. esfenvalerate + endosulfan (1-3)

No residual control and periodic treatments (4-6 sprays)

Insect resistance to three chemical classes

Section 18 permits for imidacloprid (Admire) in California

Broccoli/Cauliflower 1993 1994Lettuce 1993 1994Cucurbits 1995 1997Tomatoes 1994 -

First issue Reissue

Vegetable production statistics for CA

Broccoli 92Lettuce 71 (head)

88 (leaf)Cauliflower 89Tomato 32 (fresh)

92 (processed)Cantaloupe 58

2001 Acreage (% of US total)

Use of imidacloprid (Admire) in Use of imidacloprid (Admire) in California in 1995California in 1995

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Impacts of imidacloprid (Admire) on CA crop production

Number of insecticide applications with Number of insecticide applications with AdmireAdmire and and next best alternativenext best alternative

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eatm

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# tr

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Cost of insecticide programs with Cost of insecticide programs with AdmireAdmire and and next best alternativenext best alternative

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Yield increase due to Admire compared to Yield increase due to Admire compared to traditional alternatives in CA traditional alternatives in CA

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Broccoli Cauliflower Headlettuce

Leaf lettuce Cantaloupe

% y

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se

Value of delayed planting

Warm weather: heavy whitefly pressure

Growers shift the planting date to cooler periods to avoid peak infestations

Imidacloprid facilitated marketing at the height of infestation

Increase in grower benefits due to delayed Increase in grower benefits due to delayed planting facilitated by Admireplanting facilitated by Admire

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Broccoli Cauliflower Headlettuce

Freshtomato

Cantaloupe

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Impact of imidacloprid on insecticide use in FL fresh tomato for whitefly and other sucking pest control

Buprofezin - 2000Chlorpyrifos 22,000 -Endosulfan 89,000 34,900Esfenvalerate 5,700 2,200Imidacloprid - 8,400Methamidophos 74,500 9,100Methomyl 47,100 -Permethrin 10,900 8,000

Total 249,200 64,600

1992 2000------------- lb --------------

Colorado Potato BeetleColorado Potato Beetle

Green peach aphids

Insecticide use: CPB/aphids

• 1920’s - 1940’s Lead arsenate• 1950’s - 1960’s DDT, Parathion,

Endrin• 1970’s - Present Aldicarb, Phorate,

Methamidophos,

Carbofuran,

Endosulfan

Permethrin

CPB management problemsCPB management problems

CPB resistance to all synthetic insecticides registered for use

Cross-resistance of CPB between insecticide classes

Imidacloprid – unrelated chemistry and thus a new tool in resistance management programs

Imidacloprid treated potato Imidacloprid treated potato acreage (%) in 1999acreage (%) in 1999

Idaho 8Maine 90Michigan 93Minnesota 70North Dakota 68Oregon 35Pennsylvania 81Washington 4Wisconsin 74

Leading insecticides used for CPB Leading insecticides used for CPB control in 2001 (in order of importance)control in 2001 (in order of importance)

ImidaclopridCarbofuranPermethrinPhorateEsfenvalerateEndosulfanMethamidophosAzinophos-methylAldicarbMethyl parathionDimethoate

Reduction in insecticide use following Reduction in insecticide use following imidacloprid use in potato (1994 –1999)imidacloprid use in potato (1994 –1999)

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40

80

Maine Michigan

% r

edu

ctio

n%

red

uct

ion

Source: NASS

Pierce’s disease on grapes

Glassy-winged

Bluegreen

Sharpshooters

Pesticides registered for Pesticides registered for sharpshooter controlsharpshooter control

Dimethoate 1.32Kaolin 23.75

Imidacloprid 0.05(Admire)

Average use rate (lb/A)

Other grape insects controlled Other grape insects controlled by Admireby Admire

Grape mealybugVine mealybugLeafhopperPhylloxera

Insect management problems Insect management problems in citrus in in citrus in CACA and and FLFL

Glassy-winged sharpshooter (overwintering host)California red scale (resistant to OP &carbamates)Citricola scale (increasing in problem)

Brown citrus aphid (vectors citrus tristeza virus)

Use of imidacloprid on citrusUse of imidacloprid on citrus(Section 18 in (Section 18 in CACA and and FLFL))

Glassy-winged sharpshooterCA red scale

Citrus brown aphidCitrus leaf miner

Cotton pest problems

Escalation of secondary pest problems

Insecticide resistance

Losses due to aphids in CA cotton in 1997

Crop loss Control costs

Aphids 34 38All insects and mites 66 167

--------------- Million $ -----------------

Imidacloprid treated cotton acreage in Imidacloprid treated cotton acreage in CaliforniaCalifornia

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40

80

1995 1996 1997 1998

% t

reat

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cres

% t

reat

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cres

Source: NASS

Summary

Sucking pests have not been a significant problem to growers in the recent years, largely because of the advances in agrochemical research that resulted inthe development of imidacloprid.

American growers were able to increase crop yields,reduce crop production costs, and insecticide usefollowing the introduction of imidacloprid.

No agrochemical is immune to problems.

Conclusions

With the increasing safety and environmental concerns, there will be loss of some agrochemicals. Search for replacement products that can live up to both regulatory and grower standards necessitates continued agrochemical research.

Agrochemical research should continue to meet the increasing demands of growing population.

Continued agrochemical research will provide solutions to evolving pest and their management problems.

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