Insecticides
Insecticides
• An insecticide is a pesticide used to
kill insects.
• They include ovicides and larvicides
used against the eggs and larvae of
insects respectively.
• Insecticides are used in agriculture,
medicine, industry and the
household.
classification of insecticides
• Systemic insecticides - Insects ingest the
insecticide while feeding on the plants.
• Contact insecticides are toxic to insects
brought into direct contact.
• Natural insecticides-They are extracts
made by plants as defenses against
insects.
• Eg.-Nicotine pyrethrum and neem based
insecticides
• Plant-incorporated protectants
(PIPs)-They are insecticidal
substances produced by plants after
genetic modification.
• a gene that codes for a specific
Baccilus thuringiensis biocidal
protein is introduced into a crop
plant's genetic material.
• Then, the plant manufactures the
protein.
• Inorganic insecticides-They are
manufactured with metals like
arsenates, copper and fluorine
,sulfur compounds.
• Organic insecticides-They are
synthetic chemicals
Organochlorides
• They are the best known insecticides
• Eg.-DDT, was made by the Swiss Scientist Paul
Müller. for which he was awarded the Nobel
Prize for Physiology or Medicine in 1948.
• Later chlorinated hydrocarbons were made
• DDT works by opening the sodium channels in
the nerve cells of the insect.
• Examples- Aldrin, Endosulfan
• Endrin, Hexachlorobenzene
• Lindane (gamma-hexachlorocyclohexane)
Organophosphates
• These act by binding to acetylcholinesterase
and other cholinesterases.
• This results in disruption of nerve impulses,
killing the insect or interfering with its ability
to carry on normal functions.
• Organophosphate insecticides and chemical
warfare nerve agents (such as sarin, tabun,
soman and VX) work in the same way.
• Eg.-Dichlorvos (DDVP),Dicrotophos,
• Malathion,Monocrotophos
Carbamates
• Carbamate insecticides have similar toxic
mechanisms to organophosphates,
• but have a much shorter duration of action
and are thus somewhat less toxic.
• Eg.-Aldicarb
• Bendiocarb
• Carbofuran
• Carbaryl
Pyrethroids
• pyrethroid pesticides mimic the insecticidal
activity of the natural compound pyrethrum .
• These are nonpersistent sodium channel
modulators, and are much less acutely toxic
than organophosphates and carbamates.
• Compounds in this group are often applied
against household pests.
• Examples-Allethrin,Cypermethrin
• Deltamethrin,Permethrin
Neonicotinoids
• Neonicotinoids are synthetic analogues of the
natural insecticide nicotine .
• These are nicotinic acetylcholine receptor
agonists.
• They are applied as sprays, drenches, seed
and soil treatments—instead of
organophosphates and carbamates.
• Treated insects exhibit leg tremors, rapid wing
motion, stylet withdrawal (aphids),
disoriented movement, paralysis and death.
• Example-Imidacloprid .
Ryanoids
• Ryanoids are synthetic chemicals.
• They bind to calcium channels in
cardiac and skeletal muscle,
blocking nervous transmission.
• Example-Rynaxypyr,
Insect Growth Regulators
• Insect growth regulator is a chemical which
inhibit chitin (exoskeleton) biosynthesis in
insects.Eg.- benzoylphenyl ureas
• Diflubenzuron is used primarily to control
caterpillars which are pests.
• The most successful insecticides in this class are
the juvenoids (juvenile hormone analogues). Eg.
Methoprene
• Controls mosquitoes, several fly species, and
fleas cockroaches and white flies.
Biological insecticides
• Insecticides are produced by bacterium.
• Toxins produced by different strains of this
bacterium are used as larvicide against
caterpillars, beetles, and mosquitoes.
• Eg.- Spinosad.
• As these toxins have little effect on other
organisms they are considered more
environmentally friendly than synthetic
pesticides.
• The toxin from B. thuringiensis (Bt toxin) has
been incorporated directly into plants through
the use of genetic engineering.
Antifeedants
• Many plants have substances, like
polygodial, which prevent insects
from eating, but do not kill them
directly.
• The insect often remains nearby,
where it dies of starvation.
• Since antifeedants are nontoxic, they
would be ideal as insecticides in
agriculture.
Environmental effects
Effects on nontarget species
• Some insecticides kill other creatures in
addition to those they are intended to kill.
• For example, birds may be poisoned when
they eat food that was recently sprayed with
insecticides or
• when they mistake insecticide granules on the
ground for food and eat it.[6]
• Sprayed insecticides may drift from the area
to which it is applied and into wildlife areas,
especially when it is sprayed aerially.[6]
Thank you
Dr.Muneer kanha,M.D.
GMC,GUNTUR

Insecticides.ppt

  • 1.
  • 2.
    Insecticides • An insecticideis a pesticide used to kill insects. • They include ovicides and larvicides used against the eggs and larvae of insects respectively. • Insecticides are used in agriculture, medicine, industry and the household.
  • 3.
    classification of insecticides •Systemic insecticides - Insects ingest the insecticide while feeding on the plants. • Contact insecticides are toxic to insects brought into direct contact. • Natural insecticides-They are extracts made by plants as defenses against insects. • Eg.-Nicotine pyrethrum and neem based insecticides
  • 4.
    • Plant-incorporated protectants (PIPs)-Theyare insecticidal substances produced by plants after genetic modification. • a gene that codes for a specific Baccilus thuringiensis biocidal protein is introduced into a crop plant's genetic material. • Then, the plant manufactures the protein.
  • 5.
    • Inorganic insecticides-Theyare manufactured with metals like arsenates, copper and fluorine ,sulfur compounds. • Organic insecticides-They are synthetic chemicals
  • 6.
    Organochlorides • They arethe best known insecticides • Eg.-DDT, was made by the Swiss Scientist Paul Müller. for which he was awarded the Nobel Prize for Physiology or Medicine in 1948. • Later chlorinated hydrocarbons were made • DDT works by opening the sodium channels in the nerve cells of the insect. • Examples- Aldrin, Endosulfan • Endrin, Hexachlorobenzene • Lindane (gamma-hexachlorocyclohexane)
  • 7.
    Organophosphates • These actby binding to acetylcholinesterase and other cholinesterases. • This results in disruption of nerve impulses, killing the insect or interfering with its ability to carry on normal functions. • Organophosphate insecticides and chemical warfare nerve agents (such as sarin, tabun, soman and VX) work in the same way. • Eg.-Dichlorvos (DDVP),Dicrotophos, • Malathion,Monocrotophos
  • 8.
    Carbamates • Carbamate insecticideshave similar toxic mechanisms to organophosphates, • but have a much shorter duration of action and are thus somewhat less toxic. • Eg.-Aldicarb • Bendiocarb • Carbofuran • Carbaryl
  • 9.
    Pyrethroids • pyrethroid pesticidesmimic the insecticidal activity of the natural compound pyrethrum . • These are nonpersistent sodium channel modulators, and are much less acutely toxic than organophosphates and carbamates. • Compounds in this group are often applied against household pests. • Examples-Allethrin,Cypermethrin • Deltamethrin,Permethrin
  • 10.
    Neonicotinoids • Neonicotinoids aresynthetic analogues of the natural insecticide nicotine . • These are nicotinic acetylcholine receptor agonists. • They are applied as sprays, drenches, seed and soil treatments—instead of organophosphates and carbamates. • Treated insects exhibit leg tremors, rapid wing motion, stylet withdrawal (aphids), disoriented movement, paralysis and death. • Example-Imidacloprid .
  • 11.
    Ryanoids • Ryanoids aresynthetic chemicals. • They bind to calcium channels in cardiac and skeletal muscle, blocking nervous transmission. • Example-Rynaxypyr,
  • 12.
    Insect Growth Regulators •Insect growth regulator is a chemical which inhibit chitin (exoskeleton) biosynthesis in insects.Eg.- benzoylphenyl ureas • Diflubenzuron is used primarily to control caterpillars which are pests. • The most successful insecticides in this class are the juvenoids (juvenile hormone analogues). Eg. Methoprene • Controls mosquitoes, several fly species, and fleas cockroaches and white flies.
  • 13.
    Biological insecticides • Insecticidesare produced by bacterium. • Toxins produced by different strains of this bacterium are used as larvicide against caterpillars, beetles, and mosquitoes. • Eg.- Spinosad. • As these toxins have little effect on other organisms they are considered more environmentally friendly than synthetic pesticides. • The toxin from B. thuringiensis (Bt toxin) has been incorporated directly into plants through the use of genetic engineering.
  • 14.
    Antifeedants • Many plantshave substances, like polygodial, which prevent insects from eating, but do not kill them directly. • The insect often remains nearby, where it dies of starvation. • Since antifeedants are nontoxic, they would be ideal as insecticides in agriculture.
  • 15.
    Environmental effects Effects onnontarget species • Some insecticides kill other creatures in addition to those they are intended to kill. • For example, birds may be poisoned when they eat food that was recently sprayed with insecticides or • when they mistake insecticide granules on the ground for food and eat it.[6] • Sprayed insecticides may drift from the area to which it is applied and into wildlife areas, especially when it is sprayed aerially.[6]
  • 16.