A Guide to Integrated Pest Management

David OwensUniversity of Delaware Extension Entomology

Carvel Research and Education Center16483 County Seat Highway

Georgetown, DE 19947owensd@udel.edu

@OhBuggers

What Is A Pest?

• Pest – any organism that competes with human interest and causes economic loss

IPM Tactics

• “Know your enemy” – Sun Tzu, The Art of War

Pest groups

• Arthropods

– Super diverse, six or 8 legged creatures

– Chew leaves, bore in stalks, suck sap, transmit diseases

Important Groups of Arthropods

• Mites: 8 legs, 2 body segments, stylet mouth parts

– Herbivore, predators, and parasites

Eugene Nelson, bugwood.orgScott Bauer, bugwood.org

Important Groups of Arthropods

• Beetles

• True Bugs – aphids, stink bugs, scales

• Leps – caterpillars or ‘worms’

• Flies – maggots, some leafminers

• Grasshoppers

• Thrips

Whitney Cranshaw, Bugwood.org

Kristie Grarham, Bugwood.org

Joseph Berger, Bugwood.org

Frank Pearis, Bugwood.org

Pest Groups

• Diseases

– Viruses, fungi, bacteria, oomycetes, nematodes

– Often difficult to accurately diagnose

– Given the right conditions, can devastate a plant

Pest Groups - Diseases

Root Knot NematodeFusarium WiltPhytopthera root rot – very warm, very wet

Pest Groups - Diseases

Pest Groups

• Weeds

– A plant that doesn’t belong. Compete with crop for nutrients, water, light, and harvestability. Some parasitic.

– Start small but can quickly become a major problem.

– Possible insect/disease reservoirs

Pest Groups

• Vertebrates – usually birds and mammals eating seed, infesting grain, chewing holes, browsing on plants

Hog damage, MS

The Integrated Approach to Pest Management, or IPM

• IPM as we know it was conceptualized in 1959 by UC Berkley entomologists Vernon Stern, Ray Smith, Robert van den Bosch, Kenneth Hagen: “Insecticides should not be the only weapons of war used against pests; in addition to them, a strategy aimed at winning the millennial warfare should combine the tactical use of natural plant enemies, reinforced plant genetic qualities, and the application of adequate ecological techniques” – Ray Smith

The Integrated Approach to Pest Management, or IPM

• IPM as we know it was conceptualized in 1959 by UC Berkley entomologists Vernon Stern, Ray Smith, Robert van den Bosch, Kenneth Hagen: “Whatever the reasons for our increased pest problems, it is becoming more and more evident that an integrated approach, utilizing both biological and chemical control, must be developed in many of our pest problems if we are to rectify the mistakes of the past and avoid similar ones in the future.”

• Why the increased pest problems?

New Pests, New Hosts

• The Columbian Exchange • Potato blight – 1845 from NA to Europe,

famines in Ireland pre fungicides, famine in Germany due to lack of copper fungicides

• Hessian fly – late 1700’s?• Colorado potato beetle – fed on weeds

before mass cultivation of potato• Gypsy moth – 1869 silk industry dreams• Chestnut blight - 1904• Dutch Elm disease - 1928• European corn borer - 1917

• By 1900, half of US agricultural damage done by invasive pests

Post 1980

The Need and Background

• Pre 1800’s: crude extracts from plants – nicotine, sabadilla, pyrethrum

• 1800’s – 1939: Arsenicals, Coppers – Paris green, London purple (arsenites), lead arsenate, Bordeaux

mixture (copper sulfate + hydrated lime)

– In 1904, crop losses from INSECTS exceeded federal government budget (Marlatt, Yearbook US Dept. Ag.)

• 1939 – present: synthetic organic pesticides

The Modern Age

• DDT – synthesized in 1874, insecticide discovery in 1939

• Dr. Paul Müller won the Nobel Prize for discovery

• Saved tens of thousands from disease in WWII

• Very effective on insects, VERY cheap long residual activity, acute exposure not toxic

The Modern Age

• “we were done with dinner in time to run after the trucks as they sprayed our neighborhood several times per week, sometimes every night, with the thick and exciting bank of fog. Much like waiting for the ice cream truck, we couldn’t wait for the sound of the fogger motors ”

• 80 million tons on farms in 1958, 160 million made in 1961• Biomagnifies• Abused and banned in 1973

The Problem

• 1946 – housefly resistance to DDT in Sweden, 1 year after use

• Secondary pest outbreaks, resistance, and the pesticide treadmill

– Pest – pesticide = wipe out natural enemies, resistance, secondary pests become major pests – more pesticide – newer chemistry –resistance . . . Run out of products or ability to grow commodity

• Biomagnifies

The Solution: Integrated Approach to Pest Management

• Before modern pesticides, pest management recommendations built on an understanding of pest behavior, pest dynamics, and environmental conditions favoring or mitigating pests

• Reasoned application of biology of the pest, pest behavior, ecology, and efficiently and economically selecting inputs to maximize sustainability in a given cropping system

IPM Concepts

• Economic injury level – Lowest population density that will cause economic damage, Pest loss > Pest Control Cost

• Economic threshold – The density at which control measures should be determined to prevent an increasing pest population from reaching the EIL

IPM Concepts

• Within the Economic Threshold mindset, can tolerate injury

• Injury – a pest’s effect on plant physiology

• Damage – measurable monetary unit of loss caused by a pest

IPM Tactics

• Before selecting a management tactic, ID YOUR PEST!!!

• Biological• Physical/Mechanical• Cultural• Chemical

• Use multiple tactics ranging from least-disruptive to most toxic, harmoniously to target a pest/pest group

The Last Resort – Chemical Control

• KNOW YOUR PEST!

• “Right Product, Right Rate, Right Timing” – Dr. Mark VanGessel, UD weed specialist

The Last Resort – Chemical Control

• Product selection, timing important

The Last Resort - Chemical Control: Resistance Management

• https://youtu.be/lDa6qc93nNs

• 40 million dollars lost due to insecticide resistance alone in US

Chemical Control: Resistance Management

Chemical Control: Resistance Management

• Rotate Your Mode of Actions!

Chemical Control: Resistance Management

• Rotate MOA’s, Use multiple EFFECTIVE MOA’s

Valor XLT: Valor + chlorimuron (G14 +2)

Valor

Chlorimuron

Chemical Control: Good Practices

• Keep Records! (not just because you have to)

– Trouble shooting

– Easier diagnosis

– Faster response

• Calibrate Equipment

– Not calibrating can cost $2/acre

• The Label is the Law!

Cultural Control

• Manipulation of a cropping environment to reduce pest populations and damage

– Host plant resistance

– Planting date

– Border manipulation

– Harvest timing

– Sanitation

Open seed furrow from planting in wet ground. More favorable for slugs

Cultural Control

• Cover Crops – grown during a fallow period, can help improve soil characteristics, manage weeds, nematodes, possibly slugs

Cultural Control

• Crop Rotation - growing different, unrelated subsequent crops in the field, especially useful for disease and weed management, some insects

Richard Edwards, bugwood.org

Scott Bauer, bugwood.org

Corn rootworm damage, not usually very damaging in DE but severe pest in Corn Belt

Cultural Control

• “Life finds a way” – need for multiple management strategies

• 1910- 1990’s WCR to soybean, NCR diapause

Richard Edwards, bugwood.org

Scott Bauer, bugwood.org

Corn rootworm damage, not usually very damaging in DE but severe pest in Corn Belt

Cultural Control

• Crop Rotation - growing different, unrelated subsequent crops in the field, especially useful for disease and weed management, some insects

• Can use different herbicides on different crop, but read label for rotation restrictions

Bacterial Wilt of tomato. Tomato or Pepper grown in same field for many years, rotate out for 2-3 years

Cultural Control

• Trap crops – a small planting that is more attractive to an insect than the main cash crop. Concentrates insect activity, diverts away from the crop.

– Different species, variety, plant timing

– May be a ‘dead end’

Jude Boucher, U. Conn.

Physical Control

• Use of physical barriers to prevent pest injury

– Row covers – keep insects out https://www.youtube.com/watch?v=X-ko9gT5iA4

– Plastic mulch – weed, disease, insect control

– Screening/fencing – insect, vertebrate, disease

– Temperature modification

75% reduction in TSWV, USDA-ARS: http://www.tswvramp.org/management/

Biological Control

• Suppression of a pest by means of its natural enemies

• Classical, Conservation, and Augmentative

Classical Biological Control

• Used when a new pest introduced, no native natural enemy manages it (especially for pests that are not ‘pests’ in their original habitat)

• Brown Marmorated Stink Bug – introduced around 1996 in PA

• By 2010, caused devastating losses to tree fruit, vegetable, and field crops

• Massive home nuisance

• Native wasps ineffective

Classical Biological Control

• Asian wasp, Trissolcus japonicus, attacks 60 – 90% BMSB eggs

• Under quarantine for host specificity studies when discovered in the landscape

Classical Biological Control

https://agriculture.delaware.gov/plant-industries/spotted-lanternfly/

Conservation Biological Control

• Conserving natural enemy populations through use of selective pesticides, providing habitat and resources

Jappliedecologyblog.wordpress.com

Augmentative Biological Control

• Inoculate a crop or swamp a crop with natural enemies

• Slower to respond, need to target small pest populations

• Combine with selective pesticides

• Banker plants – providing alternative host/host habitat for biological control agent

• Ex: oat grass banker plant in greenhouses – supports cereal-infesting aphids and generalist aphid parasitoid wasps. Aphids not a pest of ‘cash crop,’ wasps sustained season long

Augmentative Biological Control

Biological Control Sources

Biological Control Sources

Successful IPM Implementation

• Anticipate pest problems – prevention

• Scout!

• Select control measure - mitigate

Scouting and Monitoring

• https://www.youtube.com/watch?v=2rXLT_vweW8

• Identify areas that need corrective action, forecast pest pressure

• You CANNOT windshield scout

Scouting - Forecasting

http://cdm.ipmpipe.org/node/1126

Scouting

• Pests tend to aggregate

• Sample field edges and interior, 5 – 10 sites per field

• Sample unit: series of sweeps, beat sheets, linear row feet etc.

• Visual, sweep, beat

Scouting

Useful Resources

Useful Resources

Purchased or downloadedhttp://extension.udel.edu/ag/vegetable-fruit-resources/commercial-vegetable-production-recommendations/http://extension.udel.edu/ag/weed-science/weed-management-guides/

Invaluable Resources

https://extension.udel.edu/ag/vegetable-fruit-resources/commercial-vegetable-production-recommendati ons/index-of-insect-disease-and-disorder-galleries/

County Extension Agents

Dan Severson and Carrie MurphyNew Castle County

Phillip SylvesterKent County

Cory Whaley and Tracy WootenSussex County