Presentation on theme: "Classes, Functions, Methods"— Presentation transcript:
1Classes, Functions, Methods Pest ManagementClasses, Functions, Methods
2Pests – 100 species cause 90% of damage Any organism that interferes in some way with human welfare or activities
3PROTECTING FOOD RESOURCES: PEST MANAGEMENT Organisms found in nature (such as spiders) control populations of most pest species as part of the earth’s free ecological services.Spiders kill far more insects than insecticides doFigure 13-27
4PROTECTING FOOD RESOURCES: PEST MANAGEMENT We use chemicals to repel or kill pest organisms as plants have done for millions of years.1600’s – nicotine from tobacco1800’s – pyrethrum from chrysanthemum flowerChemists have developed hundreds of chemicals (pesticides) that can kill or repel pests.Pesticides vary in their persistence.Each year > 250,000 people in the U.S. become ill from household pesticides.
5PEST MANAGEMENT: Conventional chemical pesticides 25% - non agriculture use (lawns, golf courses, etc)Average lawn gets 10x more per acre than croplandFigure 13-28
9Other Pesticides Rodenticides Fungicides Nematicides Algaecides A toxic chemical that kills rodentsFungicidesA toxic chemical that kills fungiNematicidesA toxic chemical that kills nematodes (roundworms)AlgaecidesA toxic chemical that kills algaeBactericidesA toxic chemical that kills bacteriaPiscicidesA toxic chemical that kills fish (unwanted species)
10Hard/Persistent Pesticides Characteristics:Composed of compounds that retain their toxicity for long periods of time. They work their way up the food chain through animals and may accumulate in their fatty tissues and stay indefinitely.ExamplesDDT and many other chlorinated hydrocarbons.
11Soft Pesticides Characteristics Examples Reduced-risk pesticides. They are short-term and don’t harm the environment or man.Examplessoaps, oils, plant extracts, baking soda, and dish liquid.
18Disease Control Save human lives Prevent insect-transmitted diseases, such as malaria (anapheles mosquito), bubonic plague (rat fleas), typhus (body lice & fleas), & sleeping sickness (tsetse fly).
19Food Production Increase food supplies and lower food costs. About 55% of the world’s food supply is lost to pests before (35%) and after (20%) harvest.These losses would be worse and food prices would rise.
20Fiber Production Crops such as cotton Kills pests like the cotton boll weevil.
21Efficiency When Compared to Alternatives Pesticides control most pests quickly and at a reasonable cost.They have a long shelf lifeEasily shipped and appliedAre safe when handled properly.When genetic resistance occurs, farmers can use stronger doses or switch to other pesticides.Proponents feel they are safer than the alternative
22Development of Safer Pesticides such as botanicals and micro-botanicalssafer to users and less damaging to the environment.Genetic engineering holds promise in developing pest-resistant crop strains.It is very expensive to develop these, so they are only doing it for large-market crops like wheat, corn, and soybeans.
26Superbugs Genetic resistance to pesticides. Insects breed rapidly; within 5-10 years (sooner in tropics) they can develop immunity to pesticides and come back stronger than before.Weeds and plant-disease organisms also become resistant.520 insect and mite species, 273 weed species, 150 plant diseases, and 10 rodent species (mostly rats) have developed genetic resistance to pesticides.At least 17 insect pest species are resistant to all major classes of insecticides
27Superpests Superpests are resistant to pesticides. Superpests like the silver whitefly (left) challenge farmers as they cause > $200 million per year in U.S. crop losses.Figure 13-29
28Case Study: Growing Germ Resistance to Antibiotics Rapidly producing infectious bacteria are becoming genetically resistant to widely used antibiotics due to:Genetic resistance: Spread of bacteria around the globe by humans, overuse of pesticides which produce pesticide resistant insects that carry bacteria.Overuse of antibiotics: A 2000 study found that half of the antibiotics used to treat humans were prescribed unnecessarily.
29Formation of New Pests Turning of minor pest into major pests. The natural predators, parasites, & competitors of a pest may be killed by a pesticide it allows the pest population to rebound.EX. DDT to control insect pests on lemon trees caused an outbreak of a scale insect (a sucking insect that attacks plants) that had not been a problem.
30Impact on Non-target Organisms Pesticides don’t stay put.The USDA says that only 2% of the insecticides from aerial or ground spraying actually reaches the target pestsOnly 5% of herbicides applied to crops reaches the target weeds.They end up in the environment
31Food/Water Contamination Pesticides run off into our water as we spray for bugs & stay on our food.Can harm wildlife and threaten human healthEx. Dirty dozen/clean 15 listsApples, grapes, strawberries, peaches, spinach
32PersistenceMany pesticides stay in the environment for a very long time. Ex. Biomagnification of DDTIncrease severity higher up in the food chain.
33Bioaccumulation/Biomagnification Increase in the concentration of a chemical in specific organs or tissues at a level higher than normal.Stored in body fat and can be passed along to offspring.Usually a concern to organisms higher on the food chain.
34The same 3 fish as they grow over lifetime Bioaccumulationan increased concentration of a chemical within an organism over timeThe same 3 fish as they grow over lifetime
35BiomagnificationBiomagnification- the increase in a chemical concentration in animal tissues as the chemical moves up the food chain.
36Minamata, JapanMental impairments, birth defects, and deaths were caused by mercury.The mercury dumped in Minamata Bay by a factory entered humans through their diet of fish.
37Pesticide Poisoning (Toxicity) Short-term exposure to high levels of pesticides can result in harm to organs and even death (Acute)Long-term exposure to lower levels of pesticides can cause cancer. (Chronic)Children are at a greater risk than adults.
38Pesticide Poisoning Symptoms Examples Nausea, vomiting, and headaches. More serious can result in damage to the nervous system & other body organs.ExamplesThe W.H.O. estimates that more than million people are poisoned by pesticides each year, & about 220,000 die.
39Carcinogen National Cancer Institute Pesticides have been shown to cause lymphomas, leukemia, brain, lung, and testicular cancers.The issue of whether certain pesticides cause breast cancer remains unresolvedResearchers have noted a correlation between a high level of pesticides in the breast's fatty tissue and cancer.
41LD-50 (Median Lethal Dose) The LD-50 is the amount of pesticide it will take, in one dose, to kill ½ of all the target organisms (usually rats & mice).Use of dose-response analysis exposes organisms to different concentrations of toxins.Threshold dose occurs once there is a negative effect
42Nervous SystemSome interfere with the nervous system, cause uncontrollable muscle twitching or paralysis.Some are nervous system poisons. Ex. Spectracide, Nicotine, DDT, Dursban, & Diazinon.
43PhotosynthesisSome pesticides inhibit photosynthesis and prevent chlorophyll formation.Ex. Stampede, Pyrazon.
44SmotheringThe vapors kill the pest by suffocating the animal. Soap can smother soft bodies of insects.Ex. flea collars, pest strip, and soap.
45DehydrationDehydration uses the fossilized remains of tiny, one-celled organisms called diatoms. It kills insects by scratching their wax outer covering and causing them to dehydrate. This is a soft pesticide.
46Inhibition of Blood Clotting Other types of pesticides cause animals (especially rats) to bleed to death by preventing their blood from clotting.
47The Ideal PesticideThe ideal pest-killing chemical has these qualities:Kill only target pest.Not cause genetic resistance in the target organism.Disappear or break down into harmless chemicals after doing its job.Inexpensive.There is no such product - always trade-offs
48Pesticides and the Law EPA The EPA & USDA & FDA are responsible for the overseeing the laws.
49ResearchPesticide companies must use 3 methods to determine pesticides health threats:Case Reports – (made to physicians) about people suffering from adverse health effectsLaboratory Investigations – (usually on animals) to determine toxicity, residence time, what parts of the body are affected and how the harm takes place.Epidemiology – (in populations of humans exposed) used to find why some people get sick while others do not
50Days to HarvestThe last day you can spray crops before you harvest them for human consumption.
51RestrictionsThe EPA sets a tolerance level specifying the amount of toxic pesticide residue that can legally remain on the crop when the consumer eats it.
52FFDCA Federal Food, Drug, and Cosmetic Act Strengthened in 1996 Sets pesticide tolerance levels
53FIFRA The Federal Insecticide, Fungicide & Rodenticide Act It was first established in 1947 & revised as recently as 1996.States what must be on a pesticide label & requires registration of all pesticides.
54Label Requirements the brand name the ingredient statement the percentage or amount of active ingredient(s) by weightthe net contents of the containerthe name and address of the manufacturerRegistration and establishment numbersSignal words and symbolsPrecautionary statementStatement of practical treatmentEnvironmental hazard statementClassification statementDirections for useRe-entry statementHarvesting and/or grazing restrictionsStorage and disposal statement.
55FQPA Food Quality Protection Act Established in 1996 Amends both FIFRA and FFDCA.
56Problems with enforcement Lack of time and money to test all compoundsInadequate enforcementPre-1972 pesticides don’t have as strict standardsBanned or unregistered pesticides can be shipped to other countriesImported food may have unsafe levels of pesticide residue
57Rachel Carson Rachel Carson lived from 1907 to 1964. She published her famous work Silent Spring in 1962.(no birds left to sing)Increased public awareness of dangers of pesticide useResulted in DDT ban in USGrassroot environmental movementFormation of EPA
58Contributions. . . it is possible to lay down such a barrage of poisons on the surface of the earth without making it unfit for life? They should not be called insecticides, but biocides.”Silent Spring heightened public awareness and concern about the dangers of uncontrolled use of DDT and other pesticides, including poisoning wildlife and contaminating human food supplies.
60Reducing Exposure to Pesticides What Can You Do?Reducing Exposure to Pesticides• Grow some of your food using organic methods.• Buy organic food.• Wash and scrub all fresh fruits, vegetables, and wild foods you pick.Figure 13.30Individuals matter: ways to reduce your exposure to pesticides. QUESTION: Which two of these actions do you think are the most important?• Eat less or no meat.• Trim the fat from meat.Fig , p. 299
61Integrated Pest Management (IPM) A limited use of pesticides along with other practices.Not a complete elimination of pesticideImportant as a form of pollution prevention – reduces risk to wildlife and humans
62Other Ways to Control Pests There are cultivation, biological, and ecological alternatives to conventional chemical pesticides.Fool the pest through cultivation practices.Provide homes for the pest enemies.Implant genetic resistance.Bring in natural enemies.Use pheromones to lure pests into traps.Use hormones to disrupt life cycles.
63Integrated Pest Management Integrated pest management (IPM) describes pest control practices where each crop and its pests are evaluated as part of an ecological system. A program is developed that includes crop management (e.g. intercropping or polyculture where multiple types of plants are planted together), and biological and chemical controls.The aim is not to eradicate pest populations, but to reduce crop damage to an economically tolerable level.An increasing number of pest control experts and farmers believe IPM is the best way to control crop pests because of the many different methods that are used.Intercropping: peas and corn
64Cereal Research Centre, AAFC Stages in IPMIPM involves several phases. Crop management and monitoring of pest levels are ongoing. When crop damage becomes unacceptable, farmers implement the following control measures in sequence and with the proper timing.Stage 1: Cultivation controls, such as hand weeding and vacuuming crops to remove insect pests.Stage 2: Biological controls, such as pheromone traps, and natural predators, parasites, and disease organisms.Stage 3: Targeted pesticide use (chemical controls), mostly based on natural insecticides. Different chemicals are used to slow the development of resistance.Hand weedingCereal Research Centre, AAFCPheromone trap
65PhysicalThis includes rotating between different crops, selecting pest-resistant varieties, planting pest-free rootstock, and vacuuming up harmful bugs.
66Other Ways to Control Pests Biological pest control: Wasp parasitizing a gypsy moth caterpillar.Figure 13-31
67Predators/ParasitesUsing natural predators & parasites to control population of pests.
68Biological Pest Control Biological control (biocontrol) is a management tool for controlling pests using parasites, predators, disease organisms.Control agents with a botanical or microbial origin (e.g. Bt toxin) are classified as biopesticides.Biological control is an important part of IPM but it is not risk free. Some biocontrol agents may even become pests themselves attacking beneficial species. The cane toad (right) was introduced to Australia to control gray cane beetle and is now a major threat to native wildlife by displacing native species.Ladybugs are voracious predators of aphidsCane toadPhoto: Ian Smith
69DiseasesUsing disease organisms (bacteria and viruses) to control pests.
70Natural RepellantsGarlic, sulfur, pyrethrins (from chrysanthemums) to help control pests.
71Microbials Used for insect wars, especially by organic farmers. EX. The Bacillus thruingensis (Bt) toxin is a registered pesticide sold commercially as a dry powder.Each of the thousands of strains of this common soil bacteria kills a specific pest.
72Timing of ApplicationAdjusting planting times so that major insect pests either starve or get eaten by their natural predators.
73Type of CropsSwitching from vulnerable monocultures to intercroping, agroforestry, and polyculture, which use plant diversity to reduce losses to pests.
74Photodegradable Plastics Using plastic that degrades slowly in sunlight to keep weeds from sprouting between crops.
75PheromonesSynthesized bug sex attractant used to lure pests into traps or attract their predators.
76GMO- Genetically Modified Organism Genetic MethodsGMO- Genetically Modified OrganismCan be controversialBanned in Europe
77The process of making a genetically modified organism. Genetically modified organisms (GMOs) or genetically modified foods (GMFs) have environmental advantages:Higher yields per acre and thus less land is needed.Permits low tillage which reduces soil erosion, energy consumption and water loss.Lower fertilizer requirement, drought, disease, frost, salinity and pest resistance.Disadvantages:Resistance may impact beneficial insectsNative plant diversity impactedHigher yields require higher inputs of herbicides and pesticidesLower genetic variabilityThe process of making a genetically modified organism.
78Other Ways to Control Pests Genetic engineering can be used to develop pest and disease resistant crop strains.Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage.Figure 13-32
79Resistant CropsPlants and animals that are resistant to certain pest insects, fungi, and diseases can be developed.This can take 10 to 20 years.Genetic engineering is now helping to speed up this process through the development of transgenic crops.
80SterilizationMales of some insect species can be raised in the laboratory, sterilized by radiation or chemicals, and released into an infested area to mate unsuccessfully with fertile wild females.Males are sterilized rather than females because the male insects mate several times, whereas the females only mate once.
81Sterilization: Screw worm Fly lays flesh eating maggots in wounds of animals…really gross!modern cattle industry provided many thousands of cows as potential hosts for the flyserious outbreak in the southern US in 1934 resulted in over 1.3 million cases of infestation and the death of over 200,000 animals.During 1959, about two billion male screwworm flies sterilized by gamma-irradiation were released in FLsimilar program was initiated in the southwestern states in 1962 and later along the Texas-Mexico borderThese efforts involved the release of as many as one billion sterile male flies every yearThe screwworm was declared eradicated in the United States by 1966
84Advantages of Organic Farming Traditional haymaking, IrelandAdvantages of organic farming include:Farmers can still make use of new high yielding crop varieties (right).Produce is pesticide free and produced sustainably.Crop type is more closely matched to the appropriate season and soil.Increases crop diversity and disrupts disease and pest cycles.Improves soil quality and structure, reducing nutrient and water loss.Decreased fossil fuels, climate impacts, extraction impacts, and air pollutants
85Disadvantages of Organic Farming Organic produceThe disadvantages of organic farming include:Yields are lower and more land is required for the same yield.Produce may be more expensive to buy, of reduced quality and with a shorter shelf life. Consumer choice may be restricted if out of season.There may be considerable bacterial contamination of produce due to high use of manures.Muck spreadingIndicates suitable crops and cultivation practices, addition of sand silt or clay, addition of lime or sulfur to neutralize soil pH, burning to release phosphorous, plant legumes to increase nitrogen, examination of irrigation practices, reduce use of inorganic fertilizers, addition of organic matter to improve soil quality.Discuss locally grown produce environmental and economic advantages.
86Svalbard International Seed Vault Living Fort Knox: designed to protect the specimens from catastrophic events, used to replenish national seed banks.Some crops, such as peas, may only survive for years. Others, such as sunflowers and grain crops, are understood to last for many decades or even hundreds of years.Photo:Global Crop Diversity Trust Mari TefreImage:Global Crop Diversity Trust
87Svalbard International Seed Vault The Svalbard International Seed Vault on the Norwegian island of Spitsbergen, 1000km from the North pole is one of the world’s newest seed vaults.It accepted its first seeds on the 26th of February 2008.It is built into the side of a sandstone mountain, surrounded by permafrost and cooled to -18oC.The vault has meter thick walls, two air locks and blast-proof doors.Photo:Global Crop Diversity Trust Mari TefreImage:Global Crop Diversity Trust
88Sustainable Agriculture An integrated system of plant and animal production practices having a site-specific application that will last over the long term.High yield polycultureOrganic fertilizersBiological pest controlIntegrated pest managementIrrigation efficiencyPerennial cropsCrop rotationUse of more water-efficient cropsSoil conservationSubsidies for more sustainable farming and fishingMoreSoil erosionSalinizationAquifer depletionOvergrazing and overfishingLoss of biodiversityLoss of prime croplandFood wastePopulation growthPovertySubsidies for unsustainable farming and fishingLess