Pest

1. Pest Pest Management Notes Any species that competes with us for food, invades lawns & gardens, destroys building materials, spreads disease, invades ecosystems, or is simply a nuisance.

2. [12-4] How Can We Protect Crops from Pests More Sustainably? • We can sharply cut pesticide use without decreasing crop yields by using a mix of cultivation techniques, biological pest controls, & small amounts of selected chemical pesticides as a last resort (integrated pest management-IPM).

3. A. Nature Controls Most Pest Populations • Natural enemies (predators, parasites, & disease organisms) control populations of most pest species as part of the earth’s free ecological services. • Our 30,000 species of spiders (such as this wolf spider) kill far more insects every year than humans do by using chemicals. Spiders are important insect predators; most do not harm humans. Figure 12-19

4. A. Nature Controls Most Pest Populations • When we clear forests & grasslands, plant monoculture crops, & douse fields w/chemicals that kill pests, we upset many of these natural population checks and balances. • Then we must devise ways to protect our monoculture crops, tree plantations, lawns, & golf courses from pests that nature once controlled at no charge.

5. B. USING PESTICIDES TO TRY TO CONTROL PEST POPULATIONS • We use chemicals (pesticides) to repel or kill pest organisms as plants have done for 225 million years (plants have been producing chemicals to ward off, deceive, or poison herbivores). • This battle produces a never-ending, ever-changing coevolutionary process: herbivores overcome various plant defenses through natural selection; then new plant defenses are favored by natural selection in this ongoing evolutionary cycle.

6. C. DEVELOPING PESTICIDES • First-generationpesticides—natural chemicals borrowed from plants. • In the 1600s, farmers used nicotine sulfate extracted from tobacco leaves as an insecticide. • Second-generation pesticides—chemicals produced in the laboratory. • DDT (dichlorodiphenyltrichloroethane) was the first 2nd-generation potent insecticide. • Turned out to be hazardous as well as helpful.

7. Classification of Pesticides Common Types

8. Herbicides • A toxic chemical that kills unwanted plants. • Kills weeds by disrupting metabolism and growth.

9. Insecticides • A toxic chemical that kills insects. • Kills insects by clogging airways, disrupting nerves and muscles, or by preventing reproduction.

10. Rodenticides • A toxic chemical that kills rodents (mice, rats, moles, squirrels, gophers, bats, etc.). • Most are stomach poisons & are often applied as baits.

11. Fungicides • A toxic chemical that controls the fungi or fungal spores which cause molds, rots, & plant diseases. • Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit.

12. Nematicides • Toxic chemicals used to control parasitic nematodes (roundworms). • Nematodes are tiny hair-like worms, many of which live in the soil & feed on plant roots.

13. Algaecides • A toxic chemical that kills algae.

14. Bactericides • A toxic chemical that kills bacteria.

15. Piscicides • A toxic chemical that kills fish (unwanted species).

16. D. PESTICIDES HAVE IMPACTS • Since 1950, pesticide use has increased 50-fold & toxicity has increased 10—100 times. Many pesticides are persistent in the environment and have significant impacts on human and animal health. • Broad-spectrum agents are toxic to many pest & nonpest species. • DDT, malathion, parathion • Pyrethrins (from chrysanthemums—natural pesticide)

17. D. PESTICIDES HAVE IMPACTS • Selective or narrow-spectrum agents are effective against a narrowly defined group of organisms. • Copper sulfate, hydrated lime, sticky materials • Pesticides vary in their persistence – the length of time they remain deadly in the environment.

18. Hard 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 accumulate in their fatty tissues (bioaccumulation); can be biologically magnified in food webs (biomagnification); & remain in the environment for years. Examples: DDT and other chlorinated hydrocarbons.

19. Soft Pesticides Characteristics: • Reduced-risk chemicals. They are short-term and don’t harm the environment or man. Examples: soaps, oils, plant extracts, baking soda, and dish liquid.

20. D. PESTICIDES HAVE IMPACTS • In 1962, biologist Rachel Carson sounded a warning that led to strict controls on the use of DDT.

21. Rachel Carson • Rachel Carson lived from 1907 to 1964. • She published her famous work Silent Spring in 1962.

22. Contributions (Rachel Carson) • “Pesticide sprays, dusts, and aerosols are now applied almost universally to farms, gardens, forests, and homes - non selective chemicals that have the power to kill every insect, the good and the bad, to still the song of birds and the leaping of fish in the streams, to coat the leaves with a deadly film and to linger on soil - all this though the intended target may be only a few weeds or insects. Can anyone believe . . .

23. Contributions . . . 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.

24. D. PESTICIDES HAVE IMPACTS • EPA states that the average lawn is doused w/10 times more synthetic pesticides per unit of land area than are put on U.S. cropland. • Each year > 250,000 people in the U.S. become ill from household pesticides.

25. E. Benefits of Pesticide Usage • Saves human lives. • Prevents insect-transmitted diseases such as malaria (carried by Anopheles mosquito), bubonic plague (carried by rat fleas), typhus (carried by body lice & fleas), & sleeping sickness (tsetse fly).

26. E. Benefits of Pesticide Usage • Increases food supplies and lowers food costs. • About 55% of the world’s food supply is lost to pests before and after harvest. • Without pesticides, these losses would be worse, and food prices would rise.

27. E. Benefits of Pesticide Usage • Increases profits for farmers. • Boosts crop yields such as cotton. • Kills pests like the cotton boll weevil.

28. E. Benefits of Pesticide Usage • They work fast. • Control most pests quickly. • Have a long shelf-life. • Easily shipped and applied. • When genetic resistance occurs, farmers can use stronger doses or switch to other pesticides.

29. E. Benefits of Pesticide Usage • Are safe if used properly. • Greater use of chemicals derived originally from plants are safer to users and less damaging to the environment than many older pesticides. • Genetic engineering holds promise in developing pest-resistant crop strains.

30. F. Problems with Pesticide Usage • Accelerate the development of genetic resistance to pesticides. • Insects breed rapidly & within 5-10 years (sooner in tropics), they can develop immunity to pesticides through natural selection and come back stronger than before (superpests). • Weeds and plant-disease organisms also become resistant.

31. Superpests • Superpests are resistant to pesticides. • Silver whiteflies challenge farmers as they cause > $200 million per year in U.S. crop losses. • This superpest is only 2 mm long!

32. F. Problems with Pesticide Usage Pesticide Treadmill or Financial Treadmill: • In response to genetic resistance, farmers may resort to increased use of pesticides, exacerbating the problem—they pay more & more for a pest control program that often becomes less & less effective.

33. F. Problems with Pesticide Usage • Some insecticides kill natural predators & parasites: by killing off beneficial organisms (ex: spiders) that help keep pests (their prey) in check, pesticides often create conditions under which new pests can flourish. • Turning of minor pests into major pests. • EX. DDT to control insect pests on lemon trees caused an outbreak of a scale insect (sucking insect) that had not been a problem before.

34. F. Problems with Pesticide Usage • Pesticides don’t stay put & can pollute the environment. • They end up in the air, surface water, groundwater, bottom sediments, food, & nontarget organisms.

35. F. Problems with Pesticide Usage • Some harm wildlife. • Pesticides applied to cropland wipe out about 20% of our honeybee colonies and damage another 15% • Also kill more than 67 million birds & 6-14 million fish. • Are also a menace to threatened & endangered species.

36. F. Problems with Pesticide Usage • Some threaten human health. • Can poison & also cause death, especially to agricultural workers in developing countries. • Children are much more susceptible to low levels of toxic chemicals because on a unit of weight basis, they eat more food, drink more water, breathe more air, & are undergoing more rapid development than adults; they also put their fingers in their mouths and spend more time outdoors.

37. F. Problems with Pesticide Usage • Short-term exposure to high levels of pesticides can result in harm to organs and even death. • Long-term exposure to lower levels can cause cancer: lymphomas, leukemia, brain, lung, and testicular

39. G. Laws & Treaties Help Protect Us From Harmful Effects of Pesticides • 3 U.S. federal agencies • EPA (Environmental Protection Agency) • USDA (U.S. Dept. of Agriculture) • FDA (Food & Drug Administration) • Regulate the sale & use of pesticides under the Federal Insecticide, Fungicide, & Rodenticide Act (FIFRA)

40. G. Laws & Treaties Help Protect Us From Harmful Effects of Pesticides • Pesticide companies must use 3 research methods to determine pesticide health threats: • Case Reports – made to physicians about people suffering from adverse health effects. • Laboratory 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.

41. Pesticide Label Requirements: • The brand name • The ingredient statement • Percentage or amount of active ingredient(s) by weight • Net contents of the container • Name and address of the manufacturer • Registration and establishment numbers • Signal words and symbols

42. Pesticide Label Requirements: • Precautionary statement • Statement of practical treatment • Environmental hazard statement • Classification statement • Directions for use • Re-entry statement • Harvesting and/or grazing restrictions • Storage and disposal statement

43. FIFRA • The Federal Insecticide, Fungicide, & Rodenticide Act • It was first established in 1947 & amended in 1972. • States what must be on a pesticide label & requires registration of all pesticides.

44. FFDCA • Federal Food, Drug, and Cosmetic Act • Strengthened in 1996 • Sets pesticide tolerance levels

45. FQPA • Food Quality Protection Act • Established in 1996 • Amends both FIFRA and FFDCA.

46. H. There Are Cultivation, Biological, & Ecological Alternatives to Conventional Chemical Pesticides. • Fool the pest through cultivation practices. • Crop rotation: keeps specialists that eat one type of crop searching from year to year for their food.

47. H. There Are Cultivation, Biological, & Ecological Alternatives to Conventional Chemical Pesticides. • Adjusting planting times: so major pests starve or get eaten by their natural predators. • Using plastic that degrades slowly in sunlight (photodegradable) to keep weeds from sprouting between crops.

48. H. There Are Cultivation, Biological, & Ecological Alternatives to Conventional Chemical Pesticides. • Provide homes for pest enemies. • Switching from vulnerable monocultures to intercroping, agroforestry, and polyculture, which use plant diversity to reduce losses to pests. • Cutting grass no lower than 3 inches high to provide a dense enough cover to keep out crabgrass & other undesirable weeds.

49. H. There Are Cultivation, Biological, & Ecological Alternatives to Conventional Chemical Pesticides. • Implant genetic resistance. • Use genetic engineering to speed up the development of pest & disease resistant crop strains (transgenic crops).

50. H. There Are Cultivation, Biological, & Ecological Alternatives to Conventional Chemical Pesticides. • Bring in natural enemies. • Use biological control by importing natural predators, parasites, & disease-causing bacteria & viruses. • This approach is nontoxic to others, minimizes genetic resistance, & saves money. • However cannot be mass-produced, is slower acting, can sometimes become pests themselves, & must be protected from pesticides sprayed in nearby fields.