in Crop Protection Strategies Caydee Savinelli Annual Crop Protection School 2015 2 Insect Resistance Experts estimate that there are over 500 species of insects and mites known to be resistant to at least one class of pesticide ID: 743117
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Slide1
Understanding Insecticide Mode of Action
in Crop Protection Strategies
Caydee Savinelli
Annual Crop Protection School, 2015Slide2
2
Insect
Resistance
Experts estimate that there are over 500 species of insects and mites known to be resistant to at least one class of pesticide. Every major agricultural crop and ornamental has one or more resistant pests. In addition to synthetic chemicals, pests can develop resistance to insecticidal soaps, B.t. and even pheromone disruption. Slide3
3
Insect Resistance Mechanisms
Target Site Resistance
The target site
is where
the insecticide acts in the
insect.
May
be genetically modified to prevent the insecticide binding or interacting at its site of action – reduces the effect of the insecticide.Metabolic ResistanceMetabolic resistance is the most common mechanism. Resistant insects may detoxify or destroy the toxin faster than susceptible insects, or quickly rid their bodies of the toxic molecules. Insects use their internal enzyme systems to break down insecticides. Resistant strains may possess higher levels or more efficient forms of these enzymes. Slide4
4
Insect Resistance Mechanisms
Penetration
ResistanceOuter cuticle of the insect slows the absorption of a broad range of chemicals.Penetration resistance is often present along with other forms of resistance.Behavioral ResistanceResistant
insects may detect or recognize a danger and avoid the toxin.
This
mechanism of resistance has been reported for several classes of insecticides, including organochlorines, organophosphates, carbamates and pyrethroids. Slide5
What is the level of arthropod resistance?
Over 550 species of arthropods are resistant to pesticides
88%
insects, 12% mitesMost of those insects come from 4 groups: Coleoptera (Beetles)
Diptera
(Flies)
Hemiptera
(Sucking Bugs)Lepidoptera (Moths & Butterflies)60%+ of all resistant arthropods are agricultural pestsRest are: animal health (ticks and lice) public health (flies, mosquitoes, cockroaches)stored product pests (grain beetles) non-target organisms (predatory mites) Source: Arthropod Pesticide Resistance Database – Michigan State University Slide6
Leading
Global Resistant Agricultural Arthropods
Common Name
Species
Order
No. active ingredients
Two Spotted Spider Mite
Tetranychus urticae
Acari
79
Diamondback
Moth
Plutella xylostella
Lepidoptera
76
Green Peach Aphid
Myzus persicae
Hemiptera
68
Colorado
Potato BeetleLeptinotarsa decemlineataColeoptera48Silverleaf WhiteflyBemisia tabaciHemiptera39European Red MitePanonychus ulmiAcari38Cotton AphidAphis gossypiiHemiptera37Cotton BollwormHelicoverpa armigeraLepidoptera33Tobacco BudwormHeliothis virescensLepidoptera33Egyptian Cotton LeafwormSpodoptera littoralisLepidoptera30
Source
: Arthropod Pesticide Resistance Database – Michigan State University Slide7
7
Does insecticide resistance mean the total loss of insecticides
?
With current agricultural practices, the development of insecticide resistance is inevitable.However, even though there is resistance, this does not mean the insecticide is no longer effective. With crop protection insecticides, it is possible to manage resistance and maintain susceptibility.Slide8
8
Are some insects more prone to resistance ?
Common claim that some insects are more prone to resistance development than others.
Exposure to insecticide is key factor.Some insects, do appear to develop resistance faster than other species, even if insecticide exposure is the same.Slide9
9
Are
mites
at high risk for resistance?20 acaricide modes of action (MoAs)Two spotted spider mite (Tetranychus urticae) has developed resistance mechanisms against 17 MoAs
Many populations have resistance to multiple
MoAs
Resistance develops
rapidly in green houses
Closed environment (limited gene flow)All year productionHigh value crops – low tolerance of pestMites - High fecundity, Short generation timeResistance in field crops generally slowerSlide10
10
IRM Implementation
Key GroupsSlide11
Insecticide Resistance
Management
IRAC’s Role
IRAC-US is a task force affiliated to CropLife America. IRAC is comprised of scientists representing many companies which develop and market agricultural chemicalsAllows companies to effectively pool resources on IRM-related issues; especially, with related chemistries or traits.Individual companies do not have the resources to carry out all aspects of IRM - Collecting & Monitoring
Gains alignment on IRM recommendations and educational messages
Serves as a coordinating group for outlining methodologies for resistance surveys
Provides funding to address emerging resistance issues
i.e. – Soybean looperSlide12
IRAC Website - www.irac-online.orgSlide13
13
Insecticide Resistance Management
Industry View
Resistance, real or perceived, can greatly diminish the value of products in the marketplaceIncrease in number & frequency of applications
Product non-performance complaints go up and farmer confidence goes down
Resistance reduces the effective life of a product
Shorter product life will lower the return on investment
With discovery
and registration costs of $200-350 million and development timelines of 8-15 years, it is important to maintain the current products in the market.Resistance management is an important component of product stewardshipSlide14
Insecticide Resistance Management
Industry’s Role
Expertise
Research & Development, Registration, Product StewardshipInteractionsRACS, Universities, Consultants, IPM Centers, CustomersLabels Mode of Action LabelingEffective rates and use patterns to minimize selection pressure
Resistance Management GuidanceSlide15
Mode of Action Classification
All products have been assigned to groups based on their
mode of action
:
i.e. pyrethroids are Group 3; Neonicotinoids are Group 4A, Spinosad is Group 5, Diamides are Group 28
Product labels
include
the number corresponding to the mode of action group.
The aim is to help product users make better decisions such as product rotations or tank mixing. Slide16
Growth
&
Deve
lop
me
n
t
T
ar
g
ets
Group
7
-
Juvenil
e
hormone mimicsGroup 10 - Mite growth inhibitorsGroup 15 - Inhibitors of chitin biosynthesisGroup 16 - Inhibitors of chitin biosynthesisGroup 17 - Molting disruptorGroup 18 - Ecdysone agonists / molting disruptorsNerve & Muscle TargetsGroup 1 - Acetylcholinesterase (AChE) inhibitors - 1A Carbamates, 1B OrganophosphatesGroup 2 - GABA-gated chloride channel antagonists - 2A Cyclodiene Organochlorines, 2B PhenylpyrazolesGroup 3
- Sodium
channel
modulators 3A
Pyrethrins,
Pyrethroids
Group 4
- Acetylcholine
receptor (nAChR
) agonists 4A
Neonicotinoids, 4C Sulfoxaflor, 4D Flupyradifurone
Group 5
- Nicotinic
acetylcholine receptor channel
agonists -
Spinosyns
Group 6
- Chloride
channel activators
- Avermectins
Group
9 - Modulators
of Chordotonal Organs
Group 14
- Nicotinic
acetylcholine receptor channel blockers
Group 19
- Octopamine
receptor agonists
Group 22
- Voltage
dependent sodium channel blockers
Group 28
- Ryanodine receptor modulators - Diamides
Respiration TargetsGroup 12 - Inhibitors of mitochondrial ATP synthesis Group 13 - Uncouplers of oxidative phosphorylation Group 20 - Mitochondrial complex III electron transport inhibitorsGroup 21 - Mitochondrial complex I electron transport inhibitorsGroup 23 - Inhibitors of acetyl CoA carboxylaseGroup 25 - Mitochondrial complex II electron transport inhibitors
Midgut TargetsGroup 11 Microbial disruptors of insect midgut membranes11A Bacillus thuringiensis, 11B Bacillus sphaericusSlide17
17
IRAC-US IRM Plan
Plant Protection Insecticides
Determine insecticide mode of action. Establish the baseline susceptibility of key high-resistance-risk pests prior to and/or in the early years of commercialization. Include mode of action group on product labels.
Provide resistance management recommendations on product labels.
Encourage use of Integrated Pest Management (IPM) practices by growers.
Develop educational literature for growers, researchers and extension agents to increase resistance management awareness, particularly at the grower level.
Monitor product performance over a wide range of geographies and observe or track changes in the susceptibility of pest populations over time. Slide18
Insecticide Mixture StatementSlide19
19
Insecticide Mixture Statement
Insecticide Mixtures
Mainly used for pest management Insecticide mixture considerations Active ingredients, use patterns, targeted pest complex.Mixtures of insecticides provide technical advantages for controlling pests
Increases level of target pest control
Increases the
spectrumSlide20
20
Insecticide Mixture Statement
All of the following should be considered when using mixtures for IRM:
Individual insecticides in mixtures should be highly effective & applied at effective rates. Mixtures with components having the same IRAC mode of action classification are not recommended for IRM.When using mixtures, consider cross-resistance issues between the individual components for the targeted pest/s.Slide21
21
Insecticide
Resistance Management
EPA’s
Role
For conventional pesticides, EPA has historically relied on voluntary measures to encourage proactive resistance management by pesticide users.
Agency-approved labels are an important tool, but resistance management labeling is voluntary (not mandatory for registrants).
Bt
Plant-Incorporated Protectants (PIPs) – a special case:EPA places a high value on preserving the significant agricultural and environmental benefits of Bt PIPsEPA requires an Insect Resistance Management (IRM) plan for each registered Bt crop. IRAC-US has provided a list of key pests with high potential for resistance and an insecticide resistance management plan to EPASlide22
22
Insecticide
Resistance Management
University’s RoleLead or participate in the development of IRM plansProvide education and lead implementation of IRM plans in respective geographies for the growers and crop consultants.Monitor susceptibility of insects of concern.
Provide feedback to companies on successes and challenges with IRM plans.Slide23
23
Neonicotinoid IRM Plan & Implementation -
Bemisia tabaci
– Arizona/California vs. FloridaArizona / CaliforniaMultiple Host CropsVegetables, Melons, Cotton
Crops grown throughout the year.
Florida
Single Host Crop
Tomato
Tomato Season - August through MaySlide24
24
Neonicotinoid IRM Plan & Implementation -
Bemisia tabaci
– Arizona/California vs. FloridaIRM Plan DevelopmentLed by university extension entomologistsTeam – Chemical Companies, Crop Consultants, Grower Groups, Commodity GroupsIRM Plan ImplementationNewsletters
Meetings
Success Measurements
Susceptibility monitoring
Grower adoption surveysSlide25
25
Neonicotinoid IRM Plan & Implementation -
Bemisia tabaci
– Arizona/California vs. FloridaAZ / CA RecommendationsGuidelines based on the cropping system
Neonicotinoid Uses
FL Recommendations
Cultural
Controls
Crop Hygiene
Tomato free period
Neonicotinoids
Application Method & TimingSlide26
26
IRM Plan & Implementation
Diamide Insecticides
IRAC Diamide Working GroupsFormed before registration of MOA Group 28 products
Global
Alignment on IRM for
Diamides
Identified
key insects of concern – U.S.InsectScientific Name
Crop
Diamondback Moth
Plutella xylostella
Brassicas
Beet Armyworm
Spodoptera exigua
Vegetables
Codling Moth
Cydia pomonella
Pome Fruit
Colorado Potato Beetle
Leptinotarsa decemlineataPotatoSlide27
27
IRM Plan & Implementation
Diamide Insecticides – IRAC-US Diamide WG
Labels - MoA Symbol, Resistance Management LanguageCollaborate with University Research & ExtensionDevelop best management guidelines for IRM
Literature pieces
Address emerging issuesSlide28
Summary
Industry is motivated to have insect resistance management as part of our product stewardship efforts in order to protect the life of our products.
IRAC is the industry task force used to create IRM guidelines, educate and promote the value of insect resistance management in crop production, ornamentals and public health.
In order for insect resistance management to be successful, we need cooperation from all stakeholders!