Chapter 20 Pesticides

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Chapter 20 -Pesticides
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What is a pest?

• Pests are living organisms that occur where they
  are not wanted or that cause damage to crops or
  humans or other animals. Examples include
• insects,
• mice and other animals,
• unwanted plants (weeds),
• fungi, and
• microorganisms such as bacteria and viruses.

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What is a pesticide?

• A pesticide is any substance or mixture of
  substances intended for
• preventing, destroying, repelling, or mitigating
  any pest.
• Though often misunderstood to refer only to
  insecticides, the term pesticide also applies to
  herbicides, fungicides, and various other
  substances used to control pests.
• Under United States law, a pesticide is also any
  substance or mixture of substances intended for
  use as a plant regulator, defoliant, or desiccant.

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Common Types of Pesticides

• Insecticides kills insects
• Herbicides kills weeds
• Fungicides kills fungus
• Nematocides kills round-worms
• Rodenticides kills rodents (rats)

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The groups of pesticides

• Chemical Pesticides
• Biopesticides

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Chemical Pesticides

• Pesticides that are created from non organic or
  biological means
• Examples are Organophosphate Pesticides,
  Carbamate Pesticides, Organochlorine Insecticide,
  and Pyrethroid Pesticides.

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Biopesticides

• Biopesticides are certain types of pesticides
  derived from such natural materials as animals,
  plants, bacteria, and certain minerals. For
  example, canola oil and baking soda have
  pesticidal applications and are considered
  biopesticides. At the end of 2001, there were
  approximately 195 registered biopesticide active
  ingredients and 780 products. Biopesticides fall
  into three major classes
• Microbial pesticides
• Plant-Incorporated-Protectants (PIPs)
• Biochemical pesticides

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Microbial pesticides

• Microbial pesticides consist of a microorganism
  (e.g., a bacterium, fungus, virus or protozoan)
  as the active ingredient. Microbial pesticides
  can control many different kinds of pests,
  although each separate active ingredient is
  relatively specific for its target pests. For
  example, there are fungi that control certain
  weeds, and other fungi that kill specific
  insects.

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Plant-Incorporated-Protectants (PIPs)

• Plant-Incorporated-Protectants (PIPs) are
  pesticidal substances that plants produce from
  genetic material that has been added to the
  plant. For example, scientists can take the gene
  for the Bt pesticidal protein, and introduce the
  gene into the plant's own genetic material. Then
  the plant, instead of the Bt bacterium,
  manufactures the substance that destroys the
  pest. The protein and its genetic material, but
  not the plant itself, are regulated by EPA.

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Biochemical pesticides

• Biochemical pesticides are naturally occurring
  substances that control pests by non-toxic
  mechanisms. Conventional pesticides, by contrast,
  are generally synthetic materials that directly
  kill or inactivate the pest. Biochemical
  pesticides include substances, such as insect sex
  pheromones, that interfere with mating, as well
  as various scented plant extracts that attract
  insect pests to traps. Because it is sometimes
  difficult to determine whether a substance meets
  the criteria for classification as a biochemical
  pesticide, EPA has established a special
  committee to make such decisions.

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Pest Types

• Algicides
• Control algae in lakes, canals, swimming pools,
  water tanks, and other sites.
• Antifouling agents
• Kill or repel organisms that attach to underwater
  surfaces, such as boat bottoms.
• Antimicrobials Antimicrobials
• Kill microorganisms (such as bacteria and
  viruses).
• Attractants
• Attract pests (for example, to lure an insect or
  rodent to a trap). (However, food is not
  considered a pesticide when used as an
  attractant.)
• Biopesticides
• Biopesticides are certain types of pesticides
  derived from such natural materials as animals,
  plants, bacteria, and certain minerals.
• Biocides
• Kill microorganisms.
• Disinfectants and sanitizers
• Kill or inactivate disease-producing
  microorganisms on inanimate objects.
• Fungicides
• Kill fungi (including blights, mildews, molds,
  and rusts).
• Fumigants
• Produce gas or vapor intended to destroy pests in
  buildings or soil.

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More types of pesticides

• Biocides
• Kill microorganisms.
• Disinfectants and sanitizers
• Kill or inactivate disease-producing
  microorganisms on inanimate objects.
• Fungicides
• Kill fungi (including blights, mildews, molds,
  and rusts).
• Fumigants
• Produce gas or vapor intended to destroy pests in
  buildings or soil.
• Herbicides
• Kill weeds and other plants that grow where they
  are not wanted.
• Insecticides
• Kill insects and other arthropods.
• Miticides (also called acaricides)
• Kill mites that feed on plants and animals.

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The last bunch of Pesticide Types

• Microbial pesticides
• Microorganisms that kill, inhibit, or out compete
  pests, including insects or other microorganisms.
  
• Molluscicides
• Kill snails and slugs.
• Nematicides
• Kill nematodes (microscopic, worm-like organisms
  that feed on plant roots).
• Ovicides
• Kill eggs of insects and mites.
• Pheromones
• Biochemicals used to disrupt the mating behavior
  of insects.
• Repellents
• Repel pests, including insects (such as
  mosquitoes) and birds.
• Rodenticides
• Control mice and other rodents.

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Pesticide Generations

• The first generation of pesticides were basically
  natural pesticides that were extracted from
  plants that were fighting against pests from the
  beginning
• The second generation of pesticides that were
  created chemically. A prime example is DDT,
  which is a potent insecticides that was known
  about since 1874

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The risks of Pesticides

• By their nature, most pesticides create some risk
  of harm - Pesticides can cause harm to humans,
  animals, or the environment because they are
  designed to kill or otherwise adversely affect
  living organisms.

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The benefits of Pesticides

• However, pesticides are useful to society -
  Pesticides can kill potential disease-causing
  organisms and control insects, weeds, and other
  pests. It also helps to prevent from a
  deterioration of vegetation

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How are we exposed to pesticides?

• Pesticides can be found, often in small amounts,
  almost anywhere worldwide. Where you live and
  your lifestyle largely determines the potential
  for exposure to pesticides.
• People are not intentionally exposed to
  pesticides, except for public health reasons.
  Instructions on the pesticide label are designed
  to minimize exposure, both to workers and the
  general public.
• Most non-occupational exposure comes from food or
  home pesticide use. In addition to use in
  agriculture and forestry, pesticides are used in
  many public places, including office buildings,
  restaurants, schools, parks, golf courses, and
  along roads, railroads and power lines.

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Pesticides are found everywhere

• You may think that pesticides are only used in
  the field however it is also commonly used within
  the household. For instance, when you go camping
  and you bring bug repellent, that is a type of
  pesticide. Another example is Raid, which can
  kill unwanted household pests.

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Food Most of the foods we eat have been grown
with the use of pesticides. Therefore, pesticide
residues may be present inside or on the surfaces
of these foods. Home and Personal Use
Pesticides You might use pesticides in and
around your home to control insects, weeds, mold,
mildew, bacteria, lawn and garden pests and to
protect your pets from pests such as fleas.
Pesticides may also be used as insect repellants
which are directly applied to the skin or
clothing.
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• Pesticides in Drinking Water Some pesticides
  that are applied to farmland or other land
  structures can make their way in small amounts to
  the ground water or surface water systems that
  feed drinking water supplies.
• Worker Exposure to Pesticides Pesticide
  applicators, vegetable and fruit pickers and
  others who work around pesticides can be exposed
  due to the nature of their jobs. To address the
  unique risks workers face from occupational
  exposure, EPA evaluates occupational exposure
  through a separate program. All pesticides
  registered by EPA have been shown to be safe when
  used properly.

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The fight for pesticideson human health

• Many people argue that pesticides have more
  benefits that risks.
• They believe that pesticides can help save lives
  by preventing almost 7 million people from
  pre-mature deaths
• They help to prevent illness from
  insect-transmitted diseases such as malaria,
  bubonic plague, typhus, and more.

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The fight for pesticides on an agricultural basis

• Pesticides lower food costs and increase food
  supplies
• This is because pests destroy about 55 of the
  worlds potential food supply.
• Without the usage of pesticides, the damage from
  pests would rise significantly and food costs
  would rise significantly because of the damage
  that we would receive from pests.

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The fight for pesticideson a business basis

• Pesticides increase profits for farmers.
• Pesticide companies estimate that for every one
  dollar that is spent on pesticides, there is a
  four dollar profit from the crops that farmers
  grow. This not only would increase crop yield
  but would also help pesticide companies profit
  and farmers to grow their crops in peace.

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Health risks

• Over 19 of commercial lettuce from major grocery
  store chains contained the pesticide DDT or DDE -
  Approximately 75 of all produce tested positive
  for various pesticide residues.  Although
  research suggests these levels can affect humans,
  the EPA does not currently require chemical
  companies to test their chemicals for immune
  system damage or subtle neurological harm.

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The benefits of pesticides out-weigh the health
risks

• Right now companies, although are not obligated
  to be tested for their chemical damages to the
  human immune system, believe that the reality is
  that pesticides, when used in the approved
  regulatory manner, pose no risk to either farm
  workers or consumers.
• Another reason they believe that pesticides are
  more beneficial then detrimental is because
  companies are developing safer and more
  effective pesticides.

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The fight against pesticides due to genetic
resistance

• The opponents of pesticides believe that the
  biggest problem of pesticides, is that they cause
  genetic resistance among the pests that they
  control. They believe that since insects breed
  rapidly, they come back even stronger each time
  because of genetics and evolution. A prime
  example is the cockroach and their incredible
  ability to create resistance against most of the
  bug sprays that it is faced against, and how they
  have survived for so many eons.

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Fight against pesticides in that they do not
target singular insects

• Opponents believe that another problem with
  pesticides is that there are broad-spectrum
  insecticides that kill natural predators and
  parasite that may have been maintaining the
  population of a pest species at a reasonable
  level.
• They also believe that wiping out natural
  predators cal also unleash new pest whose
  populations the predators had previously held in
  check, causing other unexpected effects.

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Pesticide TreadmillsThe threat to farmers
business

• One of the risks of using pesticides is the
  constant and rising costs of pesticides.
• Since pests can grow resistance to pesticides,
  farmers may undergo a program where they must
  purchase more pesticides to apply a larger dose,
  however they dosage, no matter how large, becomes
  more and more ineffective.

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Pesticides hurt the environment

• One of the major problems is that pesticides
  dont stay put
• According to the U.S. Department of Agriculture,
  no more than 2 of the insecticides applied to
  crops by aerial spraying or by ground actually
  reaches the target pests.
• Pesticides that miss their target pests end up in
  the air, surface water, groundwater, bottom
  sediments, food, and nontarget organisms,
  including humans and wildlife

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Health Problems Pesticides may Pose

• Laboratory studies show that pesticides can cause
  health problems, such as birth defects, nerve
  damage, cancer, and other effects that might
  occur over a long period of time.  However, these
  effects depend on how toxic the pesticide is and
  how much of it is consumed

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• For these reasons, the Federal Government, in
  cooperation with the States, carefully regulates
  pesticides to ensure that their use does not pose
  unreasonable risks to human health or the
  environment. In particular, the Federal pesticide
  program is designed to ensure that these products
  can be used with a reasonable certainty that they
  will pose no harm to infants, children, and
  adults.

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How does the environment break down pesticides?

• In the atmosphere, most pesticides breakdown
  rapidly by reaction with oxygen or free radicals,
  catalyzed by sunlight (indirect photolysis). Some
  pesticides break down by directly absorbing
  sunlight (photolysis). Those that persist can
  travel long distances in the atmosphere. In
  water, breakdown is usually by hydrolysis, often
  mediated by pH. In aquatic systems, pesticide
  break down by microorganisms in sediments may
  also be important. The predominant pathway in
  soil is microbial degradation, although for some
  pesticides chemical degradation is important.

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How the Government Regulates Pesticides?

• Before a company can sell or distribute any
  pesticide in the United States of America, EPA
  must review studies on the pesticide to determine
  that it will not pose unreasonable risks to human
  health or the environment. Once EPA has made that
  determination, it will license or register that
  pesticide for use in strict accordance with label
  directions.

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Other Solutions to pest control

• Crop rotation
• Trap Crops
• Intercropping
• Cross breeding plants
• Introduce natural enemies
• Insect birth control
• Hot water can zap pests

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Crop Rotation and protection

• Crop rotation is when the type of crop planted in
  a field each year can be changed.
• Another method is to plant rows of hedges or
  trees can be planted around fields to hinder
  insect invasions and provide habitats for their
  natural enemies.

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Trap Crops

• Trap crops are basically planted to lure pests
  away from the main crop, that is usually human
  food supply. For example, in Nicaraguan cotton
  fields several rows of cotton are planted several
  months ahead of the regular crop to attract boll
  weevils, which can then be destroyed by hand or
  with small doses of pesticides.

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Intercropping

• Growers cal switch from vulnerable monocultures
  to intercropping, agroforestry, and polyculture,
  which use plant diversity to reduce losses to
  pests. The diseased or infected plants and
  stalks and other crop residues that harbor pests
  can then be removed from the crop field.

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Crossbreeding

• Benefits
• Plants and animals that are genetically resistant
  to certain pests, insects, fungi, and diseases
  can be developed. This would then lower the
  costs of pesticides and remove many fears of
  health risks
• Risks
• However, resistant varieties usually take a long
  time and lots of money to develop by conventional
  crossbreeding methods. More over, if the
  crossbreeding fails, then more research has to be
  done in order for success, which in the end would
  take more money to accomplish

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Natural Predators

• Biological control using predators, parasites,
  and pathogens can be encouraged or imported to
  regulate pest populations. More than 300
  biological pest control projects worldwide have
  been successful, especially in China and Cuba.
• Biological control has several advantages because
  each predator focuses on select target species
  and also this method is nontoxic to other species
  and also to humans.

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Insect Birth Control

• Males of some insects pest species can be raised
  in the laboratory, sterilized by radiation or
  chemicals. And then released into an infest area
  to mate unsuccessfully with fertile wild females.
  This technique works best if the females mate
  only once because once they fail, they fail and
  the females will not search for another mate that
  may be fertile.

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Hot water?

• Some farmers have begun using the aqua heat
  machine, which sprats boiling water on crops to
  kill weeds and insects. Water is boiled and
  drawn from a large stainless steel tank mounted
  on a tractor and sprayed on crops using a long
  boom.
• So far it has worked well on cotton, alfalfa, and
  potato fields and in citrus groves in Florida,
  where the machine was invented.

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Are Some Pesticides Safer Than Others?

• Biologically-based pesticides, such as pheromones
  and microbial pesticides, are becoming
  increasingly popular and often are safer than
  traditional chemical pesticides. In addition, EPA
  is registering reduced-risk conventional
  pesticides in increasing numbers.

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What is "Integrated Pest Management?

• Age-old, common-sense practices are what many
  people associate with IPM. Today many growers no
  longer apply pesticides to food on a regular
  basis regardless of whether or not there are
  insects, weeds, or other pest problems. In some
  parts of the country, food is being marketed as
  IPM food.
• Some practices for preventing pest damage may
  include
• inspecting crops and monitoring crops for damage,
  and
• In technical terms, Integrated Pest Management
  (IPM) is the coordinated use of pest and
  environmental information with available pest
  control methods to prevent unacceptable levels of
  pest damage by the most economical means and with
  the least possible hazard to people, property,
  and the environment.

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How can IPM help control pests

• First keep in mind that IPM is a plan that is
  evaluated as if the crop and its environment is
  an ecological system.
• Basically the overall purpose of IPM is not the
  eradication of pests but the reduction of crop
  damage to an economically tolerable level.

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• THE END
• NO MORE!!!!