Pesticides and Pest ControlPesticides and Pest Control

Brian Kaestner

Saint Mary’s Hall

Brian Kaestner

Saint Mary’s Hall

Thanks to Miller and ClementsThanks to Miller and Clements

Orange - groundwater contaminationPink - nitrate contaminationRed - arsenic contamination

PestsPests

Compete with humans for foodCompete with humans for food

Invade lawns and gardensInvade lawns and gardens

Destroy wood in housesDestroy wood in houses

Spread diseaseSpread disease

Are a nuisanceAre a nuisance

May be controlled by natural enemiesMay be controlled by natural enemies

Pesticides: TypesPesticides: Types

Chemicals that kill undesirable organisms

Chemicals that kill undesirable organisms

Insecticides Insecticides

Herbicides Herbicides

Fungicides Fungicides

Rodenticides Rodenticides

See Table 20-1 p. 504See Table 20-1 p. 504

Grasshopper

Gypsy mothcaterpillar

Fig. 20.2a, p. 505

Fig. 20.2b, p. 505

European red mite

Fig. 20.2c, p. 505

Boll weevil

Pink bollworm

ranges overlap

Fig. 20.3, p. 506

Fig. 20.11 , p. 514

Fig. 20.4, p. 507

600

500

400

300

200

100

01950 1960 1970 1980 1990 2000 2010

Year

Nu

mb

er o

f sp

ecie

s

Boll weevilGypsy moth cateripllar

Insects and mites

Weeds

Plant diseases

First Generation PesticidesFirst Generation Pesticides

Primarily natural substances Primarily natural substances

Sulfur, lead, arsenic, mercury Sulfur, lead, arsenic, mercury

Plant extracts: nicotine, pyrethrumPlant extracts: nicotine, pyrethrum

Plant extracts are degradable Plant extracts are degradable

Refer to Appendix 6 p. A8 Refer to Appendix 6 p. A8

Second Generation PesticidesSecond Generation Pesticides

Primarily synthetic organic compounds Primarily synthetic organic compounds

630 biologically-active compounds 630 biologically-active compounds

Broad-spectrum agents Broad-spectrum agents

Narrow-spectrum agents Narrow-spectrum agents

Target species Target species

Nontarget species Nontarget species See Table 20-1 p. 504See Table 20-1 p. 504

Characteristics of an Ideal PesticideCharacteristics of an Ideal Pesticide

Kill only target pests Kill only target pests

Harm no other psecies Harm no other psecies

Break down quickly Break down quickly

Not cause genetic resistance Not cause genetic resistance

Be more cost-effective than doing nothing Be more cost-effective than doing nothing

Fig. 20.12, p. 514

MH

MH

JH

MH

JH

JH

MH

Pupa

Eggs

Larva

The Case for PesticidesThe Case for Pesticides

Save human lives Save human lives

Increase supplies and lower cost of food Increase supplies and lower cost of food

Work better and faster than alternatives Work better and faster than alternatives

Health risks may be insignificant compared to benefits

Health risks may be insignificant compared to benefits

Newer pesticides are becoming safer Newer pesticides are becoming safer

New pesticides are used at lower rates New pesticides are used at lower rates

The Case Against PesticidesThe Case Against Pesticides

Genetic resistance Genetic resistance

Can kill nontarget and natural control species Can kill nontarget and natural control species

Can cause an increase in other pest species Can cause an increase in other pest species

The pesticide treadmill The pesticide treadmill

Pesticides do not stay put Pesticides do not stay put

Can harm wildlife Can harm wildlife

Potential human health threats Potential human health threats

Fig. 20.5, p. 507

Pesticide Regulation in the United StatesPesticide Regulation in the United States

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)

Tolerance levelsTolerance levels

EPA Evaluation of chemicalsEPA Evaluation of chemicals

Inadequate and poorly enforcedInadequate and poorly enforced

Food Quality Protection Act (FQPA)Food Quality Protection Act (FQPA)

Other Ways to Control PestsOther Ways to Control Pests

Economic threshold Economic threshold

Adjusting cultivation practices Adjusting cultivation practices

Use genetically-resistant plants Use genetically-resistant plants

Biological pest control Biological pest control

Biopesticides Biopesticides

Insect birth control Insect birth control

Hormones and pheromones Hormones and pheromones

Ionizing radiation Ionizing radiation

Integrated Pest ManagementIntegrated Pest Management

Ecological system approachEcological system approach

Reduce pest populations to economic threshold

Reduce pest populations to economic threshold

Field monitoring of pest populationsField monitoring of pest populations

Use of biological agentsUse of biological agents

Chemical pesticides are last resortChemical pesticides are last resort

Effects of IPMEffects of IPM

TimeTime

Pes

t d

ensi

tyP

est

den

sity

Original pest population

Introductionbiological control

Equilibriumposition

Equilibrium position

Reduced pest population

Economic threshold

Fig. 20.7, p. 507