Pest management

Question 1

Intro

pest and specific

Answer 1

organism that interferes with human welfare activites - vaguely define- context specific ie bulbs S Africa versus Australia - swap and think other is pretty
sometimes due to numbers- quantity of locusts
can be bio control gone wrong ie cane toad

Question 2

examples (5)

Answer 2

cotton bollworm
Black rat
black wattle
malagasy locust
cane toad

Question 3

cotton bollworm

Answer 3

predates on corn
causes $1.1 billion damage
fungi develops in damages - GMO species goo and untouched

Question 4

black rat

Answer 4

Ancapa island 3 inlets
80-90s decline of seabirds as rat introduced - eat bird eggs
4 years developng programme
helicopters for special rodenticides
10 yrs later eradication and birds thriving + new species - growth rate up to 25% in seabirds

Question 5

black wattle

Answer 5

firewood, can extract tannin for leather common in S africa
But outcompetes other spp
uses more water than indigenous spp- water levels drop thus dry rivers-dam not effectoive-less irrigation-farmer cost
when cleared also problem as leopards came down as used to use as cover. affected wildstock as ate sheep.

Question 6

malagasy locust

Answer 6

destroyed HALF of corn and rice crops in a matter of weeks. 100 swarms in madagascar, 5 billion locusts and 100,000 tonnes of vegatation affected.
climate change - wetter season allowed them to breed
usually arent pest.
Famine caused as well as famine t ocattle. $3 billion was spent on aid. was a v serious problem. Country was too poor to spend money on pesticides or fuel.

Question 7

cane toad

Answer 7

introduced to remove beetles, ended up being pesst as ate everything- also eliminated larger predators as is toxic – bio control gone wrong

Question 8

pesticides and natural example

Answer 8

not a new concept, chemical that repel or kill pests. Natural example is LANTANA- chemical relaease then kills pests around it. Chemicals have synthesised many.

Question 9

rachel carson

Answer 9

Silent Spring “they should not be called pesticides but biocides” 1962- raised public awareness about toxicity and food contamination. Regards build-up of DDT killing birds and she grew up without hearing them sing.

Question 10

hard and 2 examples

Answer 10

high toxicity, persistent (long term), build up in enviro, up food chain – removing predator can lead to prey pop explosion. Examples are DDT and Chlorinated hydrocarbons

Question 11

soft

Answer 11

low toxicity, not persistent (short-term), easily degraded by enviro-break down in water/air – don’t harm people or enviro – soaps, washing up liquid, oils baking soda, plant extracts.

Question 12

target specific examples

Answer 12

herbicides, nematicides, rodenticides, insecticides, algaecides, and bactericides

Question 13

how do the ywork 5

Answer 13

1) CNS
2) Photosynthesis inhibitors
3) Smothering- oils
4) Dehydration
5) Inhibition of blood clotting
Sparks ethical debates wrt animal use.

Question 14

how do they work heading

Answer 14

LD-50 – MENDELIAN LETHAL DOSE – figure out how much on average takes to kill the pest – action on 5 things

Question 15

benefits (3)

Answer 15

1) Food – 55% before and after harvest of food is lost – would be even higher withouth pesticides – food prices would rise
2) Clothing – without control of cotton bollworm would have lestt cotton produced
3) Disease – Tse Tse fly (sleeping sickeness), Plasmodium (malaria), traitome (Chagas disease) rat fleas (bubonic plague) typhus (body lice and fleas) – many disease would be worse. Can save human lives. Prevent insect transmitte disease – vectors often cryptic

Question 16

BENEFITS OF APPLICATION 6

Answer 16

1) Quick
2) Cheap
3) easy to apply
4) safe when handled correctly
5) long shelf life
6) if gen resistance can switch to other pesticides / stronger ones

Question 17

disadvanatages 4/8

Answer 17

1) Non-specific /non target organisms- USDA – 2% from aerial spray reach pests only. 5% applied to crops reach target weeds.mobile through air (soft), hard (water)
2) Bioaccumulation – increase in chemical concentration in specific tissues /organs and scored in bodyfat
3) Persistence in environment – DDT has large lag time between application and degradation- unsure costs.
4) Food /water contamination – run off into our water supplies after sprayed

Question 18

disadvantages last 4/8

Answer 18

5) Pesticide poisoning - short term to high levels= death, long term to small levels = CANCER and CNS WHO estimates . 3 million people poisoned each year – mostly developing countries – lack of regulations. Avoid poisoning – wash/scrub , organic or grow own veg, trim fat from meat and eat less or no meat.
6) Genetic resistance –wthin 5-10 yrs can be resistant- 17 insect pests are resistant to ALL major insecticide classes silver whitefly super pest causes farmers $200 million a year in crop losses (US)
7) Antibiotic resistance – many bacteria resistant. ½ antibiotics prescribed unnecessarily
8) New pests – can effect nat predator balance. Predators must be killed so natural pop rebound. DDt example- use of DDT caused outbreak of SCALE insects that weren’t there before.

Question 19

Safer pesticide development:

Answer 19

BOTANICALS AND MICROBOTANICALS – asafer as nat products

Question 20

regulation

Answer 20

Regulating use – tolerance levels- health authorities- max toxic residue legally allowed  LEGISLATION AND LABELLING PRODUCTS

Question 21

traditional alternative control 2

Answer 21

1) Physical: rotate between crops, selective breeding, grafting to bind strong roots and fruit bearing.
2) Ecofarmer: each crop planted exclusively as part of ecosystem- integrated approach

Question 22

bio control 4

Answer 22

1) Predator/parasites – wasp for gypsy moth caterpillar- can become pest itself
2) Microbials – Bt toxin – soil bacteria toxin kills specific pests ie weeds
3) Diseases – use bacteria and virus- synthetic biology – alga from scratch-grows on eroding soils to stop erosion
4) Natural repellents – garlic, sulphur, pyrethins

Question 23

other alternative control 5

Answer 23

1) Timing – so pest starves / certain season/day time mean less pest prone system T
2) Type of crop – diversity reduces losses T
3) Photdegradable plastics- plastics that degrade in sun – stop weeds
4) Traps using pheromones- to lure pests into trap
5) Vacuum pests – time consuming)

Question 24

genetic 4

Answer 24

resistant
gene drive
sit
integrated

Question 25

resistant

Answer 25

1) Resistant crops – transgenics to acieve pest resistant crop ie Tomato plant (used to take 1-20yr-natural breeding

Question 26

SIT

Answer 26

3) SIT - Sterilization – male raised in lab,sterilised by gamma radiation or chemicals,released into enviro, mate unsuccessfully wilth wild ferile females. Pops die out – success in Zanzibar and Florida screwworm – need large numbers

• Steroid hormone 20E passed to mozzie during sex induces egg laying and makes her unreceptive to males therefore stops mating AGAIN. Now basing sterilising compound on this.
• Plutella diamond moth – double sex DSX gene was alternatively spliced to create lethal genetic system- also promise to broaden SIT control

Question 27

steroid hormone

Answer 27

20E

Question 28

integrated technique

Answer 28

houseflies causing diarrhoea- 2 formulas being developed- chemical and microbrial. Overcome resistance to pytheroids- will hit market in 6 months – good results in poultry farm trials. NBAIR but patent will be sold to pivate players once market has been developed

Question 29

old fly resistant to

Answer 29

pytheroids-