Pesticides
Chemicals used to control or manage pest populations
1/67
| Term | Definition |
|---|---|
| Pesticides | Chemicals used to control or manage pest populations |
| What is the purpose of pesticides? | To reduce pest populations to a non-economic level |
| Pests | Plants and animals that compete with man for food and fiber, or attack man directly |
| Examples of pesticides: | Insecticide, Acaricide, Herbicide, Fungicide, Nematicide, Rodenticide, Piscicide, Avicide, and Repellents |
| Insecticide | kills insects |
| Acaricide | kills mites-ticks |
| Herbicide | kills weeds |
| Fungicide | kills fungus |
| Nematicide | kills nematodes |
| Rodenticide | kills rats/mice |
| Piscicide | kills trash fish |
| Avicide | affects birds |
| Repellents | repels birds |
| Pesticide Categories: | Non-persistent, Persistent, Accumulative |
| Non-persistent | breaks down quickly to harmless or less harmful products |
| Persistent | breaks down slowly and may remain in the environment for long periods of time. generally, more harmful to non-target species |
| Accumulative | may build up in the bodies of animals in food chains, including man |
| Examples of non-persistent pesticides: | organosphate and carbmate pesticides |
| Examples of persistent pesticides: | Organochlorine pesticides, 2-4 D |
| Examples of accumulative pesticides: | DDT, dieldrin, heptachlor, aldrin, toxaphene |
| How do pesticides harm the environment? | Injure plants, illegal residues, direct mortality, chronic exposure hazards, chronic effects of pesticides |
| How do pesticides harm the environment? Injure plants | Phytotoxicity |
| How do pesticides harm the environment? Illegal residues | Loss of Sale |
| How do pesticides harm the environment? Direct Mortality | Acute Toxicity of Non-target species insects- beneficials, predators, parasites, fish food Fish- nearby water Birds- in & around target area Man accidentally (improper use) |
| How do pesticides harm the environment? Chronic Exposure Hazards | Carcinogenicity, Teratogenicity, Mutagenicity, Reproductive Problems- Birds (eggshell thinning in sensitive species), Fish- Trout reproduction, Limit soil use, Limit water use |
| Carcinogenicity | the potential to cause cancer |
| Teratogenicity | may cause birth defects |
| How do pesticides harm the environment? Chronic effects of Pesticides | long term exposure to sublethal levels may be more important than acute mortality due to a single exposure |
| Pesticide Movement: | Drift, Erosion, Leaching, Volatilization, Codistillation, Streams, Air, Animals |
| Pesticide Movement: Drift | Problem when off target - droplet size: smaller droplets are more effective for pest control, use when less than 5 mph wind |
| Pesticide Movement: Erosion | Wind and Water - most pesticides are absorbed on soil particles or organic matter in the soil |
| Pesticide Movement: leaching | little movement |
| Pesticide Movement: Codistillation | soil and water |
| Pesticide Movement: streams | sediment |
| Pesticide Movement: Air | global movement |
| Pesticide Movement: Animals | residues |
| Basic ingredients of life: | Soil, Air, Water, Sunlight |
| Effects of soil pollution: | Sterilization, Limit Use |
| Sources of Contamination: | Direct applications, indirect - plants and animals |
| Persistence in soil: | insecticide itself, soil type, moisture, microorganisms, soil temperature, cover crops, cultivation, mode of action, formulation, translocation |
| Persistence in soil: Insecticide itself | half-life of a persistent pesticide (DDT) may be in the soil for several years |
| Persistence in soil: Soil type | Heavy soils tend to increase persistence as compared to sandy or light soils. Higher rate for heavy clay soils. |
| Persistence in soil: Moisture | generally increases the breakdown of pesticides and lessens their persistence. Increases volatization and codistillation |
| Persistence in soil: Microorganisms | also degrade pesticides |
| Persistence in soil: Soil temperature | increasing soil temperature increases volitization, codistillation, and degradation of persistence. |
| Persistence in soil: cover crops | increase persistence |
| Persistence in soil: cultivation | decreases persistence |
| Persistence in soil: formulation | granules more persistent than sprays |
| Persistence in soil: Translocation | a device used purposely to control certain pests with systemic pesticides - removes some residues from the soil into the plants |
| ____ commonly will contain residues amounting to ___ of the soil level of organochlorine insecticides | Soybeans; 10% |
| Water sources of contamination | Direct Application, Accidental Application and Drift, Runoff from Treated Areas, Waste from Manufacturing, Leaching, Pesticide Containers, Sewage, Concern |
| Water sources of contamination: Direct Application | made to water to control or manage pests like trash fish, noxious weeds, mosquito larvae, etc. |
| Water sources of contamination: Accidental Application and Drift | aerial applications to crops near streams and lakes sometimes results in accidental direct applications and drift |
| Water sources of contamination: Runoff from Treated Areas | carries both water soluble and insoluble pesticides into drainage systems |
| Water sources of contamination: Waste from Manufacturing | happens occasionally |
| Water sources of contamination: leaching | into subsurface water an area of concern |
| Water sources of contamination: Pesticide Containers | sometimes wash into lakes and streams, many placed deliberately |
| Water sources of contamination: Sewage | from towns and cities |
| Water sources of contamination: Concern | acute toxicity of some pesticides to fish |
| Air sources of contamination: | Drift, Volatilization, Codistillation, Dust deposited through rain or dust, More than one pesticide, Synergistic reaction, Antagonistic reaction |
| Drift | Air sources of contamination: during application process |
| Volatilization | Air sources of contamination: from soil, plant, animal, and water surfaces. |
| Codistillation | Air sources of contamination: with water |
| Dust deposited through rain or dust | Air sources of contamination: globally |
| More than one pesticide | Air sources of contamination: frequently used to control a complex of pests - check label for compatibility |
| Synergistic reaction | Air sources of contamination: two or more chemicals give activity exceeding that which would have been normally expected |
| Antagonistic reaction | Air sources of contamination: two or more chemicals exert activity below or less than that which would have been expected |