1
Q
What is a Pest?
A
A purely human concept, a pest is any organism that adversely affects human interests.
2
Q
Pest, Broad Interest Types:
A
- Animal
- Plant
- Microorganism
- Viruses/Bacteria
3
Q
Problems Caused by Pests
A
- Resource Competition (They reduce our global harvest.)
- Discomfort
- Vectors of Disease
4
Q
(Pests Problems) Resource Competition - Reduction of Global Harvest:
A
- Fungi, Nematodes, Bacteria, Viruses: Destroy Plants
- Insects: Attack cotton, tobacco, potatoes
- Weeds: Reduce corn, soybean yields
- Wild mammals, rodents, birds: Consume harvest
- Termites: Structural Damage
- Cockroaches, rats, mice: Food Contamination
5
Q
(Pests Problems) Discomfort
A
- Lice: Severe itching, infections, hardened skin
- Fleas: Disease transmission, painful bites
- Mites: Scabies, dermatitis
- Chiggers (Mite): Skin irritation (Waist/Armpits)
- Bedbugs: Hide, Feast on a Blood meal (Can last 6 months w/o blood meal)
- Spiders: Very few poisonous, black widow/brown recluse/aggressive house spider
6
Q
(Pests Problems) Discomfort - Brown Recluse
A
The brown recluse spider is found throughout south-central and southeastern United States. It can be identified by the violin-shaped marking on its back.
7
Q
(Pests Problems) Vector
A
An organism that transmits a disease causing organism (pathogen) from one host to another.
8
Q
Vectors of Disease - Mosquitoes
A
- Malaria - Plasmodium (parasite)
- Yellow fever, West Nile Virus, dengue fever all viral
- Controlling population, repellents (DEET)
- Dengue is worst viral disease transmitted by Mosquito
- Malaria is worst parasitic disease transmitted by Mosquito
9
Q
(CH11) Definition of Atmosphere
A
The whole mass of air surrounding the earth.
- Buffer that keeps us from being peppered by meteorites
- A screen against deadly radiation
- The reason radio waves can bounce for long distances around the planet
10
Q
(CH11) Atmospheric Evolution
A
- Infant planet Earth: Atmosphere primarily hydrogen and helium
- Gradually replaced by outgassing of volatile materials from Earth’s interior
- Evolution of green plants -> Modern oxygen-rich atmosphere
11
Q
(CH11) Chemical Composition of the Atmosphere
A
Gas composition of dry air by volume:
- 78% Nitrogen (N2)
- 21% Oxygen (O2)*
- 0.9% Argon (Ar)
- 0.03% Carbon Dioxide (CO2)*
- Trace amounts: neon, helium, krypton, xenon, dydrogen, methane, and nitrous oxide
- Directly enter into biological processes
12
Q
(CH11) Atmosphere Layers
A
- Extends approximately 50 miles above the earth
- Uniform composition of gasses
- Subdivided into 3 major regions based on temperature zones:
- Troposphere
- Stratosphere
- Mesosphere
13
Q
(CH11) Troposphere
A
- Sea level to approximately 8 miles above earth
- Where most life activities and weather phenomena occur
- Decrease in temperature with increase in altitude (5.4 Degrees F drop every 1,000 feet increase)
- Contains water vapor and dust
- Tropopause, upper limit
14
Q
(CH11) Stratosphere
A
- Directly above troposphere
- Temperature gradient reversal
- Gradual increase in temperature with increase in altitude (up to 32 degrees F)
- Almost no water vapor or dust
- Ozone layer (8-15 miles above earth)
- Stratopause, upper boundary (30 miles above earth)
15
Q
Vectors of Disease - Flies
A
- Feed on feces and transmit bacteria to food
- GI diseases: typhoid fever, cholera, dysentery and parasitic worm infections
16
Q
(CH11) Mesosphere
A
- Above stratosphere
- Decrease in temperature with increasing altitude
- Meteors or rock fragments burn
- Some references indicate that there are two or more layers:
- Thermosphere
- Exosphere
17
Q
(CH11) Where is the International Space Station?
A
Mesosphere
18
Q
(CH11) Role of Atmosphere
A
-Regulates quality and quantity of solar radiation that enters/leaves the biosphere
*Biosphere- life zone of planet Earth, includes all living organisms
*Our biosphere distinguishes Earth from all other planets in the solar
system
-Reflection and absorption
19
Q
(CH11) Radiation
A
- Energy emitted in the form of waves (light) or particles (photons)
- The electromagnetic (EM) spectrum is the range of all types of radiation
- Can be expressed in terms of energy, wavelength, or frequency
- Solar energy - subdivided into categroeis, depending o the wavelength of the radiation
20
Q
(CH11) Ultraviolet Radiation
A
- 230-320 nm range can have serious adverse health effects on living organisms
- Strongly absorbed by living tissues
- DNA, major target of UV damage
- Excess UV exposure = lethal or mutational effects
- Major concern is skin cancers
21
Q
(CH11) UV Rays
A
- Defense mechanisms developed by living organisms
- Shielding devices:
- Fur
- Feathers
- Shells
- Darkly-pigmented skin
- Light-avoidance behaviors
- Shielding devices:
- Evolution off DNA repair mechanisms
22
Q
(CH11) UV Radiation and Ozone Layer
A
- Ozone layer absorbs the most UV radiation
- Layer created by UV radiant energy breaking (O2) molecules into single oxygen atoms that recombine with O2 molecules to form ozone O3
23
Q
(CH11) Ozone Formation
A
- UV energy splits O2 which joins other O2 molecules to form ozone
- State of dynamic equilibrium
24
Q
(CH11) Human Impact on the Earth-Atmosphere System
A
-Depletion of ozone layer by chemicals that react/destroy ozone molecules
*CFC’s - chlorofluorocarbons; synthetic chemicals used as
refrigerants and aerosol propellants;
*Halons - bromofluorocarbons; fire suppressant;
*1978 - nationwide ban on ozone-depleting gases
25
(CH 8) Vectors of Disease - Cockroaches
Asthma trigger, prevalent among inner-city neighborhoods
26
(CH 8) Vectors of Disease - Body Lice
* Typhus fever, bacteria passed via feces
| * Trench and relapsing fevers
27
(CH 8) Vectors of Disease - Lyme Disease
```
Lyme Disease (Borrelia Burgdorferi)
*Most common tick-borne disease in U.S.
```
28
(CH 8) Vectors of Disease - Rocky Mountain Spotted Fever
Rocky Mountain Spotted Fever (Rickettsia rickettsii)
| *Frequently fatal
29
(CH 8) Vectors of Disease - Q Fever
```
Q Fever (Coxiella Burnetii)
*Rare, more often from feces, fluids (herd animals)
```
30
(CH 8) Vectors of Disease - Tularemia
Tularemia (Francisella tularensis)
| *Bites, dermal, ingestion, inhalation
31
(CH 8) Vectors of Disease - Ticks (Blood Meal)
* Lyme Disease
* Rocky Mountain Spotted Fever
* Q Fever
* Tularemia
32
(CH 8) Modern Pesticides
* Began with the invention of DDT in 1939
* Paul Muller won Nobel Prize for DDT
* Banned in 1972
33
(CH 8) Types of Pesticides
* Insecticides
* Herbicides
* Rodenticides
* Fungicides
34
(CH 8) Insecticides
* Inorganic compounds, toxic to humans, and damaging to crops.
* Mode of action:
- Stomach poisons: Insects ingest through mouth.
- Contact poisons: Penetrate body wall.
- Fumigants: Enter respiratory system.
35
(CH 8) Synthetic Organic Insecticides
Broad-spectrum contact poisons: one insecticide kills all pest insects it touches.
36
(CH 8) Chlorinated Hydrocarbons
* Persistent in the environments - residue breaks down very slowly; long period of protection
* Repeated applications unnecessary
* Residue to accumulate in fatty tissues of living organisms
* Persistent Organic Pollutants (POPs) banned in U.S.
37
(CH 8) Persistent Organic Pollutants (POPs)
Dirty Dozen
*International treaty ratified in 2004 to stop their use except for specific applications - hazardous environmental & health effects.
38
(CH 8) Organophosphates and Carbamates
* Not persistent (two weeks to break down)
| * Variably toxic to humans, use with great care
39
(CH 8) Pyrethroids
* Synthetic chemical analog of pyrethrum, a derivative of chrysanthemum flowers
* Low toxicity, safe to use indoors
* More expensive, but lower rates of application
40
(CH 8) Botanical Insecticides
* Pyrocide - natural pyrethrum
* Chemfish - rotenon, derived from a tropical legume
* Neem - extracted from South Asian neem tree
41
(CH 8) Herbicides
* Weeds compete with crop plants for nutrients and water, reducing crop yields
* Weeds make harvesting more difficult
* Some weed species poison livestock
42
(CH 8) Herbicide Types
* Preplanting Herbicides: Applied to soil before weeds expected to germinate.
* Post-emergents: Applied to soil or onto foliage after sprouting.
* Selective: Kill only certain types of plants.
* Contact: Kill any growing plant part
- 2, 4-D was the first synethic herbicide
* Translocated: Absorbed from soil through roots or foliage into vascular system of plant
43
(CH 8) Herbicide Health Problems
Evidence suggests exposure can cause genetic mutations, cancer, and birth defects, in addition to:
* Non-Hodgkin's lymphoma
* Persistent asthma in children
44
(CH 8) Agent Orange
2,4,5-T
* Chemical defoliant discovered to contain Dioxin (as a contaminant) - terminated in 1980's (fat soluble, stores in human tissue)
* Linked with cancer and genetic defects (Vietnam war exposure)
45
(CH 8) Herbicide Use Pro
Use of herbicides in crops grown U.S. has resulted in:
* Yield increases
* Savings for growers
* Reduced soil erosion
46
(CH 8) Rodenticides
* Cause internal hemorrhaging in rats when consumed
* Some rodenticides extremely toxic to humans
* Studies have shown a 4X risk of congenital heart defects among children born to women using rodenticides during first trimester.
47
(CH 8) Environmental Impact
DDT and DDE minimize the deposition of calcium carbonate into egg shells-thinning:
* Rapid decline in predatory bird populations
* Residues of DDT today in most living organisms
* Malaria almost eliminated by DDT
- Resurgence in tropics
- Affects 500 million people per year
- DDT being re-employed for malaria control
48
(CH 8) Environmental Impact of Pesticides
1. Development of Resistance
2. Killing of Beneficial Species
3. Environmental Contamination
49
(CH 8) Rachel Carson
Wrote the book, Silent Spring, which discussed insecticide misuse (DDT).
* Had an expertise in biology and in writing.
- Writer for U.S. Fish and Wildlife Service
50
(CH 8) Development of Resistance
Cycle of Pesticide Resistance:
* Inherited resistance
* Small % of pesticide population survives
* Survivors multiply; resistant offspring
51
(CH 8) Killing of Beneficial Species
Non-specific:
* Often kill non-target species (honeybees)
* 90% of pesticides never reach intended target
52
(CH 8) Target Pest Resurgence
Application is quickly followed by a sudden increase in pest numbers to a level higher than before because natural enemies killed.
53
(CH 8) Secondary Pest Outbreak
Rise to prominence of plant eating species that previously had not been of concern because natural enemies kept their populations down.
54
(CH 8) Environmental Contamination
* Pesticide residues are found virtually everywhere.
* Direct killing of organisms exposed to chemicals.
* Indirect killing (depletion of food or habitat)
* Groundwater contamination (rural and urban)
* Indirect contamination via food chains
- Not excreted, stored in fatty tissues, organs
- Concentration occurs along the food chain
55
(CH 8) Biomagnification
Process by which the concentration of toxic substances increases in each successive level in the food chain.
56
(CH 8) Bioaccumulation
The accumulation of a substance (such as a toxic chemical) in an organism over time.
57
(CH 8) Hazards to Human Health
Exposure Routes:
* Oral
* Dermal
* Inhalation
58
(CH 8) Acute pesticide poisoning
* Estimated 25 million/year among farm works in developing countries (WHO)
* Immune system dysfunction
* Symptoms: Headache, Weakness, Fatigue
* Organophosphate Poisoning: SLUDGE, Coma, Death
59
(CH 8) Chronic pesticide poisoning
Cancer:
*60% of herbicides, 90% of fungicides, 30% of insecticides are potential carcinogens
Disruption of endocrine and immune systems:
*May be more serious long-term threat leading to sterility
*Immune system suppression in children and elderly
-Infectious disease incidence increase contact
dermatitis seen
-Allergic reactions and chemical intolerance
60
(CH 8) Dietary Exposure
* Food Quality Protection Act of 1996
- Tolerance levels set by EPA
- Must take into account consumption habits of infants and children, and neurological differences
- Also address cumulative effects of pesticide residues
- Ten-fold safety margin for children
61
(CH 8) Integrated Pest Management
Strategy that combines natural controls with prudent use of pesticides.
* Low impact sustainable agriculture
- Changing the crop
* Low impact pest control
End result = Less pesticides
62
(CH 8) IPM Steps
1. Natural Enemies
2. Microbial Pesticides
3. Sex Attractants
4. Insect Growth Regulators
5. Sterile Insect Technique
6. Host Plant Resistance
7. Sanitation
63
(CH 8) IPM Step 1 - Natural Enemies
Some effectiveness, large scale
| *Beetles, wasps, praying mantis, ladybugs
64
(CH 8) IPM Step 2 - Microbial Pesticides
* Introduce diseases, toxins into pest population
* Bacteria, fungi, viruses, protozoa
* Bacius thuringiensis (Bt) toxin
Bacillus thuringiensis (Bt) is a spore forming bacterium that produces crystals protein (cry proteins), which are toxic to many species of insects.
65
(CH 8) IPM Step 3 - Sex Attractants
Lure pests intro traps or beneficial predator species to an infested area.
* Phermone traps
* Only effective on adults; limited utility
66
(CH 8) IPM Step 4 - Insect Growth Regulators
Chemicals that mimic natural growth substances; disrupt life cycle when introduced at proper stage.
* Chitin inhibitors - exoskeleton
* Juvenoids - Prevent development into adulthood
* Ineffective against larvae; limited utility; Incorrect - Methoprene is used against larvae
67
(CH 8) IPM Step 5 - Sterile Insect Technique
- Infertile males introduced into population
* Treated with chemicals or radiation
- Sterile males outnumber normal males
- Produce infertile eggs
- Most effective against pests in which females mate only once
68
(CH 8) IPM Step 6 - Host Plant Resistance
Genetic Resistance to Pests
* Selective breeding
* Genetic engineering - introduced desired characteristic from one species to another
* Development of Bt resistance in pests
69
(CH 8) IPM Step 7 - Sanitation
- Keep food and water inaccessible to pests
- Make undisturbed shelter areas unavailable for pests
- Build structures to be impenetrable to pests
70
(CH 9) Adulteration
```
Deliberate addition of inferior or cheaper material to a purse food product in order to stretch out supplies and increase profits.
*Harmless ingredients
*Toxic substances
-Poisonous food colorings
and flavorings
```
71
(CH 9) Commonly Adulterated Foods
* Pepper
* Tea
* Cocoa Powder
* Milk
* Coffee
72
(CH 9) 1906 Pure Food and Drugs Act
* The first federal law to protect consumers from adulteration, mislabeling, and harmful ingredients.
* This act + subsequent legislation = cases of adulteration in U.S. are rare
73
(CH 9) Food Contaminants
* Substances accidentally incorporated into foods.
* Introduced during harvesting, processing or packaging.
- Dirt
- Hairs
- Animal feces
- Fungal growth
- Insect fragments
- Pesticide residues
- Traces of growth hormones or antibiotics
74
(CH 9) Defect Action Levels
* Established by FDA
* Specifies limit of contamination allowable; if exceeded, legal action taken to remove product from market
* Maximum allowable contamination, set where there is no danger to human health
75
(CH 9) Growth Hormones
* Five FDA-approved hormones for use in U.S. livestock
| * Used with 90% of cattle in U.S.
76
(CH 9) Growth Hormones rBGH/rBST
Recombinant bovine growth hormone (rBGH) or recombinant bovine somatotropin (rBST) used in dairy cows every 14 days to boost milk production 10-20%
77
(CH 9) Bioterrorism Act (2003)
* Registration with FDA required of foreign facilities that manufacture, process, pack or hold food for consumption in the U.S.
* Foreign exporters required to notify FDA in advance of food shipments to the U.S.
78
(CH 9) Foodborne Disease
1. Natural Toxins in Food
2. Microbial Contamination
* Bacteria
* Virus
* Parasites
3. Other
79
(CH 9) Ergot
Claviceps purpurea fungus infects grains
80
(CH 9) Alfatoxin
Carcinogen; Aspergiullus flavus and A. parasiticus infect nuts and grains
81
(CH 9) Salmonellosis
* Salmonella spp.
* Common foods: Poultry, meat, sprouts, eggs
* Onset of symptoms: 6 hrs to 3 days
* Some remain carriers for months
82
(CH 9) Liseriosis
* Listeria monocytogenes
* Common foods: Soft cheeses, cold cuts, hot dogs, milk, foods not heated
* Onset of symptoms: 4 days to weeks
* Very dangerous to pregnant women
* Zero tolerance for Listeria in foods (FDA)
83
(CH 9) Campylobacteriosis
* Campylobacter jejuni
* MOST COMMON BACTERIAL FOOD POISONING AGENT
* Common foods: Undercooked chicken, turkey, unpasteurized milk, clams
* Onset of symptoms: 1-10 days
* Up to 10% may develop serious, long term complications
84
(CH 9) Escherichia coli O157:H7
* Normal flora of health cattle
* Common foods: Undercooked beef, unpasteurized fruit juice, sprouts, lettuce
* Low ineffective dose; potent toxin
* Onset of symptoms: 1-10 days
* 2-7% of cases result in serious ailment
* 60,000 cases with 50 deaths/yr.
85
(CH 9) Vibriosis
* Vibrio vulnificus, V. parahaemolyticus
* Marine bacterium in unpolluted ocean water
* Common foods: Raw oysters and other shellfish
* Onset of symptoms: 1-3 days
* Dangerous in immunocompromised
