1 / 13

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

lam
Télécharger la présentation

Pests & Bioamplification Foodwebs in Grassland vs. Potato Field

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

More Related