Pesticide Groups

So what is a pesticide?

Pesticide Groups

Insecticides – kills insectsHerbicides – kills weedsFungicides – kills fungiRodenticides – kills rodentsBactericide – kills bacteriaMolluscicide – kills snails and slugsNematicide – kills nematodes

Pesticide Groups

Avicide – kills birdsOvicide – kills eggsAcaricide/miticide – kills mitesTermiticide – kills termitesPiscicide – kills fishRepellants – repels or discourages pestsAttractants – attracts pestsHormones – plant growth regulators &

juvenile growth regulators

Insecticides

Used to kill insect pestsEnters insect as contact, stomach or

systemic poisonsPhysical toxicants Protoplasmic poisonsNeural poisonsCytolytic poisonsMuscle poisons

Herbicides

Used to kill weed pestsPhysical toxicantsAuxin-like effectsMetabolic inhibitorsPhotosynthesis inhibitors

Rodenticides

Used to kill rodent pestsAnticoagulantsBenzenamines – affects liver and kidneysBotanicals – derivatives of plants

Rodenticides

Fungicides

Used to control fungal pathogensElectron transport chain inhibitorsEnzyme inhibitorsNucleic acid metabolism inhibitorsProtein synthesis inhibitorsSterol synthesis inhibitors

The Killer Fungus

Repellants

RepellantsIntended to repel pestsChemical repellantsEfficacy variesPest specificCan also include various devices

Attractants

AttractantsIntended to attract pests Usually used for trappingPheromones, baits, other chemicals

Variations on a Theme

Pesticides can be:synthetically produced organic chemicalsnaturally occurring organic chemicalsnaturally occurring inorganic chemicalsmicrobial agents

Variations on a Theme

Some chemicals not commonly thought of as pesticides:chlorine – added to swimming pools kills

algaehousehold disinfectantsinsect repellantsplant growth regulators

A Few Words About

Toxicity

Toxicity

The capacity of a chemical to cause injury

Can be referred to as “potency”By their nature – pesticides are toxicThey are intended to destroy pestsNot all pesticides present the same

hazardThe more toxic – smaller doses are

required

Toxicity

Toxicity to humansOral exposure (ingesting)Dermal exposure (skin contact)

Toxicity

Chronic toxicity long term exposure

Acute toxicity immediate exposure

Lethal Dose – LD50

Necessary amount of pesticide to kill 50% of a test population

Oral and dermal LD50

measured in mg/kgthat’s milligrams of pesticide per kilogram of

target body weight

Remember – 1 kilogram (kg) = 2.2 pounds

Lethal Dose – LD50

Ex. LD50 = 2

2 mg of pesticide per kg of body weight can be lethal

Determine:

Body weight in kilograms

LD50

Lethal Dose – LD50

Next:

Multiply body weight by LD50

Ex.

For a person weighing 220 lbs and an LD50 = 2

or

2 mg/kg of pesticide

(2mg/kg) (100kg) = 200mg

or 0.2 grams

Lethal Concentration – LC50

Lethal Concentration – LC50

Concentrations measured in air or watermicrograms/liter

Adjuvants

Materials added to pesticides for various reasons, inc.:mixing & applicationenhancementreduce surface tensionextend the lifebuffers & acidifiers

Adjuvants

Continued:reduce driftcompatibilityreduce foamingattractantscolorantsdeodorizers

Pest Groups

Pest Identification

Proper identificationTo which category does the pest belong?

Kingdom Animalia Kingdom PlantaeKingdom MoneraKingdom FungiViruses, viroides, and MLOs

Pest Identification

Common names reflect the host organism

Lists of “acceptable common names”Weed Science Society of AmericaEntomological Society of America

Most pesticide labels refer to the “common name”

Invertebrate Pests

Animals without backbonesIncludes

insectsspiders, mites and ticksmollusksnematodes and wormsetc.

Invertebrate Pests

What do these have in common?Insects, mites & ticks, centipedes,

millipedes, sowbugs, scorpions, etc.Arthropods – large group of invertebratesArthropododa – “jointed foot”Small, w/jointed legs and body parts,

external skeletonMicroscopic to several inches

Class Insecta

Life Cycles

Insect life cycles fall into two categoriesSimple metamorphosisComplete metamorphosis

Simple Metamorphosis

Young – nymphs or instarsNymphs resemble adultsMolting increases sizeWings are bud-like and fully form at last

moltNymphs and adults live in same habitat

Simple Metamorphosis

Simple Metamorphosis

Complete Metamorphosis

Adults and juveniles differ in formLarvae often worm-likeLarvae similar in appearance but

increased in size after each moltWings develop in final moltLarvae typically have chewing

mouthpartsAdults tend to have sucking mouthparts

Complete Metamorphosis

Pupa forms at final moltPupa often covered by a cocoonAdult emerges form pupa at final moltPale in color, wings short and soft upon

emergence Color develops Wings extend and harden

Complete Metamorphosis

Complete Metamorphosis

Spiders

Class ArachnidaTwo distinct body parts

- Cephalothorax- Abdomen

BeneficialNuisance indoorsFew are dangerous

Mites and Ticks

Class ArachnidaTwo distinct body parts

- Gnathosoma- Idiosoma

Some mites are beneficialTicks are pests and can vector disease

Two-Spotted Mite

Mite Pests & Locations

Some common mite pests

- Fuchsia Gall Mites

- Two-Spotted Mites

- Citrus Mites- Persea Mites

Locations of mite pests- Undersides of

leaves- Vegetative and

flower buds- On fruit

Mite Damage & Controls

DamageSucks juices from plant cellsStippled appearance to foliageRusseting on fruit skinCan cover plants with fine webbing

ControlsMiticides or AcaricidesPredaceous mitesMaintenance of plantsUse low N fertilizersReduce dustControl ants

Insects

Class InsectaThree distinct body parts

- Head- Thorax- Abdomen

Wings (if present)

Insect Anatomy

Insect Mouthparts

Vary by speciesUsed to identify speciesChewing insects damage by chewing or

boring- Caterpillars, grasshoppers, various beetles

Piercing-sucking suck juices from plantsAphids, leafhoppers, scale, thrips, mites,

mealybugs, true bugs, etc.

Insect Mouthparts

Insect Mouthparts

Insect mouthparts:

a, antennae

c, compound eye

lb, labrium

lr, labrum

md, mandibles

mx, maxillae

Order Orthoptera

Grasshoppers and Allies

Order OrthopteraCharacteristic – spiny hind legsIncludes grasshoppers, crickets, katydidsLife cycle – simple metamorphosisFound just about everywhereChewing mouthpartsDamage to foliage and new growth, rootsDifficult to control in the landscape

Two-Stripped Grasshopper

Long-Horned Grasshopper

Crickets

Field Cricket

Jerusalem or Sand Cricket

Cockroaches

Order BlattariaClosely related to OrthopteraDivided into two groupsSpiny hind legsSimple metamorphosisChewing mouthpartsMostly an indoor pestContaminate food storesSpreads disease

Controls Various insecticidesTrapsBait stationsBoric acidDiatomaceous earthAnd….

Cockroaches