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Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

Pests & Bioamplification Foodwebs in Grassland vs. Potato Field. Pests & Bioamplification Foodwebs in Grassland vs. Potato Field. Pests & Bioamplification Foodwebs in Grassland vs. Potato Field. Pests & Bioamplification Pesticide: a substance used to kill a pest

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Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

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  1. Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

  2. Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

  3. Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

  4. Pests & Bioamplification Pesticide: a substance used to kill a pest herbicides kill plants insecticides kill insects fungicides kill mouldsetc

  5. Pests & Bioamplification Pesticide: a substance used to kill a pest herbicides kill plants insecticides kill insects fungicides kill mouldsetc Broad-spectrum pesticide: effective against many types of pests e.g. DDT is toxic to most insect species Narrow-spectrum pesticide: effective against only a few types of pests e.g. Bt, a modern pesticide from bacteria is toxic only to caterpillars

  6. Pests & Bioamplification How pesticides work: 1. Physical harm: diatomaceous earth scratches the waxy outer coating of insects so they dehydrate

  7. Pests & Bioamplification How pesticides work: 1. Physical harm: diatomaceous earth scratches the waxy outer coating of insects so they dehydrate 2. Biological harm: some herbicides interfere with photosynthesis

  8. Pests & Bioamplification Issues with pesticides: 1. Non-target species: pesticides often kill species they were not intended to kill e.g. a broad-spectrum insecticide may kill predatory insects that normally feed on pests

  9. Pests & Bioamplification Issues with pesticides: 1. Non-target species: pesticides often kill species they were not intended to kill e.g. a broad-spectrum insecticide may kill predatory insects that normally feed on pests 2. Bioaccumulation: the increasing concentration of a pesticide as it moves up the food chain e.g. DDT is a long-lasting insecticide that wiped out song bird populations in the 1960s

  10. Pests & Bioamplification Bioaccumulation: e.g. DDT leached into a lake from fields herring gull egg (6.3 ppm) smelt (0.43 ppm) (fish) freshwater shrimp (0.03 ppm) ppm = parts per million

  11. Pests & Bioamplification Persistent chemicals: the bioaccumulation occurred because these pesticides lasted a long time in the environment and could be passed up the food chain -today pesticides are developed to break down quickly to avoid this buildup

  12. Pests & Bioamplification Pesticide Resistance: when a species targeted by a pesticide are no longer affected by it. -happens by chance mutations of DNA -once it occurs, these individuals with resistance produce the most offspring and the resistance quickly spreads to the entire species -the more frequently the pest reproduces, the faster resistance will develop

  13. Pests & Bioamplification Organic Farming:the system of agriculture that relies on non-synthetic pesticides and fertilizers Integrated Pest Management: a system that uses a combination of physical, chemical, and biological controls

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