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PESTS AND PESTICIDES  PESTS?  PESTICIDES

• First-Generation • Second Generation  BIOAMPLIFICATION  INTEGRATED

PEST MANAGEMENT

• Chemical Control • Biological Control • Pesticide Resistance

An organism is considered a pest if:  Humans believe it to be UNDESIRABLE (‘gross’)  It has a NEGATIVE impact on the human environment.  It is in COMPETITION with a HUMAN USE for a resource.

TWO types of pesticides 1. FIRST GENERATION PESTICIDES ORIGIN: NATURAL eg. arsenic, lead, mercury, nicotine 2. SECOND GENERATION PESTICIDES ORIGIN: HUMAN-MADE/SYNTHETIC eg: DDT, penicillin

Pesticides are chemicals used to kill various pests. 4 TYPES INSECTICIDE: HERBICIDE: FUNGICIDE: BACTERICIDE:

kills INSECTS kills plants kills mould/fungi kills bacteria

Pesticide types have changed over time. Older pesticides were FAT-SOLUBLE. • when eaten, these pesticides attach to fat cells. • they PERMANENTLY remain in the organism. Newer pesticides are WATER-SOLUBLE • when eaten, they do not accumulate in fat cells. • these can be flushed out of an organism’s system.

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 DDT

 AKA:

BIOAMPLIFICATION BIOMAGNIFICATION  Occurs

in food chains when FAT-SOLUBLE PESTICIDES build up in the fat cells of higher level consumers.

 NEGATIVE

EFFECTS OF DDT:

• Egg shell thinning in top

carnivores, such as the Bald Eagle • Thin shells meant HIGH RATES of chick mortality  It

takes about 15 y for DDT to break down in the environment.

(Dichlorodiphenyltrichloromethane) second generation  - a FAT-SOLUBLE insecticide to control insects that: • Feed on agricultural crops • Damage forests (ex: spruce budworm) • Carry diseases (ex: malaria) –

- VERY EFFECTIVE SIDE EFFECTS??

-

 Alternatives?

• Ban DDT and other fat-soluble

pesticides. Now banned in CANADA and but SOME COUNTRIES are still using it.

• Use water-soluble pesticides. • Use sustainable alternatives to

pesticides.  DDT LINK

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 AKA:

 Uses

A

 Highly

IPM sustainable approach to managing pests that involves:

effective

 DISADVANTAGES:

• PREVENTION

• BIOACCUMULATION • Not TARGET-SPECIFIC • Not 100 % EFFECTIVE (some

• AVOIDANCE • MONITORING • SUPPRESSION  MAIN TYPES

chemicals to control insects.

pests not killed) • Could lead to PESTICIDE

OF IPM

RESISTANCE

• CHEMICAL CONTROL • BIOLOGICAL CONTROL

 Uses

natural ecological relationships to control pests.

 They

are more TARGET-SPECIFIC

 DISADVANTAGES:

• Expensive • Short-Term Effectiveness • Organisms simply move to another area

 Methods

• • • •

include using: NATURAL PREDATORS DISEASE ORGANISMS COMPETITORS PHEROMONES



NATURAL PREDATORS Use a natural predator to wipe out a species eg.  Shrews and spruce sawfly  Ladybug larvae and woody aphids  Parasitic wasp and spruce budworm  Tiny fly and hemlock looper  aphid and wasp

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 DISEASE

ORGANISMS Introduce a disease into a population  eg. Hemlock looper and BT bacteria

 COMPETITORS

Bring in another organism to outcompete eg.  Zebra mussel outcompetes pearly mussel

 PHEROMONES

- these are chemical “perfumes” produced by males and females to attract mates - used to attract pests and then sterilize them or trap them!

 Some

pests are naturally immune to pesticides.

 After

the non-immune pests are killed off, the immune PESTS reproduce a new generation that are all PESTICIDE RESISTANT.

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3.

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#6, p. 58 What are 3 POSITIVE EFFECTS of using PESTICIDES to manage pests? What are 3 NEGATIVE EFFECTS of using PESTICIDES to manage pests? Let’s say you have your share of pests at homecaterpillars, earwigs, mice, dandelions, & wild baloneys What are 3 ALTERNATIVES that you could employ rather than using pesticides?

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