Pesticide Pollution (p1)

Question 1

What is a pest?

Answer 1

Any organism that competes with or adversely affects a population of plants or animals that are of economic importance to humans

Question 2

List some ways that pests may harm a crop.

Answer 2

• Reducing the crop harvest by causing ill health
• competing for resources (light, space, nutrients, water)
• Killing the crop
• Feeding on crops, reducing the harvest and it’s quality (e.g appearance )
• Causing human disease

Question 3

What percentage of the world’s food harvest is lost to pests and diseases?

Answer 3

1/3

Question 4

Define monoculture.

Answer 4

A single crop grown in large quantity in an area, which makes it easier for pests to spread

Question 5

What are pesticides?

Answer 5

Toxic chemicals used to kill pests but may harm other species

Question 6

What is specificity in the context of pesticides?

Answer 6

Which pest it’s targeting however no pesticide is so specific that it only kills the target species; non-target species can be harmed if exposed to high doses

Question 7

What is persistence in relation to pesticides?

Answer 7

Some pesticides are chemically stable and do not break down quickly, allowing them to spread widely and have longer-term effects

Question 8

Explain bioaccumulation.

Answer 8

Liposoluble pesticides build up in fat and oil droplets in cells faster than they are broken down or excreted

Question 9

What is biomagnification?

Answer 9

Biomagnification is the increased concentration of substances as you move up the food chain

Question 10

What is DDT?

Answer 10

Dichlorophenyltrichloroethane, a synthetic pesticide used extensively in the past, particularly for malaria control

Question 11

List some examples of organochlorine pesticides.

Answer 11

• DDT
• Aldrin
• Dieldrin
• Endrin

Question 12

What are organophosphates?

Answer 12

*Neurotoxins that affect enzymes used in nerve functioning
* low persistence
*low liposolubility

Question 13

What are pyrethroids?

Answer 13

Synthetic derivatives of a natural pesticide from chrysanthemum flowers, not persistent and low toxicity to mammals

Question 14

What are neonicotinoids?

Answer 14

Insecticides chemically similar to nicotine, neurotoxic with high insect toxicity but low vertebrate toxicity

Question 15

True or False: Neonicotinoids have been implicated in the decline of bees worldwide.

Answer 15

True

Question 16

How can damage from pesticides be controlled?

Answer 16

• Restriction on use of harmful pesticides
• Use of non-persistent pesticides
• Use of specific pesticides
• Application timings to reduce impact on non-target species
• Non-pesticide techniques

Question 17

What is crop rotation?

Answer 17

Growing different crops each year in a cycle to prevent pest populations and disease build-up

Question 18

Fill in the blank: Pesticides can cause _______ effects on non-target species.

Answer 18

direct and indirect

Question 19

What is an indirect effect of pesticides?

Answer 19

Other species affected due to lack of food, pollinating insects, or the death of predators or competitors

Question 20

How do surface acting insecticides work?

Answer 20

They are sprayed on the crop to provide a toxic coat that kills pests if they land or eat the crop

Question 21

What is a potential disadvantage of systemic pesticides?

Answer 21

They may be eaten by humans as they are absorbed in plant tissue

Question 22

What is the impact of persistent pesticides on the environment?

Answer 22

They can lead to bioaccumulation and biomagnification, affecting non-target species

Question 23

What is crop rotation?

Answer 23

Growing different crops in a 4-5 year cycle to prevent pests and improve soil health

Crop rotation helps reduce pest populations and disease by not allowing pests to thrive on the same crop year after year.

Question 24

How does crop rotation help prevent pests?

Answer 24

It reduces pest presence by alternating crops, which prevents the build-up of pests and disease

Pest species populations decline in winter, and planting different crops disrupts their life cycles.

Question 25

What are companion crops?

Answer 25

Crops grown together with other plants to increase harvest yields ## Footnote An example is growing onions with carrots to mask the smell of carrots from root fly.

Question 26

What is a barrier crop?

Answer 26

A crop that protects another crop from pests ## Footnote Onions can act as a barrier crop for carrots by masking their scent.

Question 27

What is the role of pest attraction in crop protection?

Answer 27

Certain plants attract pests away from main crops ## Footnote For example, nasturtiums attract blackfly pests, protecting bean crops.

Question 28

What are predator habitats?

Answer 28

Habitats that increase populations of natural pest predators ## Footnote Examples include beetle banks for black ground beetles and ladybirds.

Question 29

What is a pheromone trap?

Answer 29

A method using scent to trap one sex of an insect to prevent breeding ## Footnote For instance, pheromone traps can be used for cocoa pod borers.

Question 30

How does biological control work?

Answer 30

Using a predator, parasite, or disease to control pest populations ## Footnote Cactoblastis moth is used to control prickly pear cactus in Australia.

Question 31

What is genetic resistance to disease in pest control?

Answer 31

Using engineered diseases to control pests ## Footnote An example is using Bacillus thuringiensis against Gypsy moths.

Question 32

What is the sterile male technique?

Answer 32

Breeding sterile males to mate with females, preventing offspring ## Footnote Used to control screw worm flies in livestock.

Question 33

True or False: The screw worm has been eradicated from the USA.

Answer 33

True ## Footnote Screw worm has also been eradicated from several Central American countries.