Insecticides

1. Insecticides and
rodenticides

2. Insecticide

3. Definition

4. CLASSIFICATION
CONTACT
POISON
Kills by
contact
e.g. pyrethrum,
DDT, HCH,
dieldrin
STOMACH
POISON
When ingested
causes death of
insects
e.g. Paris green,
sodium
fluoride
FUMIGANTS
Kills by act of
vaporization of
fumes
e.g. sulphur
dioxide

6. Pyrethrum
• Obtained from dried heads of the flower
Chrysanthemum cinerariafolium
• active ingredients pyrethrins I and II,
• Pyrethrum is characterized by rapid
knockdown action (nerve poison)
• Drawback: very unstable and has no residual effect.
• Ready to spray solution containing 0.1% pyrethrins, sprayed at
the rate of 1 oz /1000 cu. Ft. area

7. Mineral Oils
– Kerosene oil, diesel oil, petrol and crude engine oil
– used as mosquito larvicides.
– The oil film cuts off the air supply, enters and blocks the
trachea, may act as a stomach poison, and also lowers surface
tension which prevents larvae from floating.
– Malariol is the best and easiest larvicidal oil to use for
Anopheline and Culicine larvae.

8. DDT( dichloro- diphenyl- trichloroethane )
White amorphous powder with unpleasant smell
Soluble in organic solvents
Causes paralysis, convulsions, & finally death
of insect (takes several hours to kill)
Residual action may last 18 months
Dosage:
1. As residual spray ( 5 % ) @ 100-200 mg. per sq. ft area
2. As space spray ( 5-10 % ) @ 200 mg. per sq. ft over large area
Considered as “environmental Pollutant“ – persistence in living
organisms and plants

9. HCH/BHC( Benzene hexachloride,
hexachlorocyclo- hexane/ Lindane)
White or chocolate colored powder
with musty smell
slightly volatile
Irritant to eyes, nose and skin
Kills insects by direct contact &
vapor effects
Has short residual effects
( 3 months)
More insecticidal than DDT
Dosage: 20-25 mg of gamma HCH
per sq. ft for residual treatment

10. Malathion
Least toxic of all OP compounds
Yellow or clear brown liquid with
unpleasant smell
Also available in powder form
Dosage: 100-200 mg per sq. ft every 3 months
Used as an alternative to DDT
Very useful as a Ultra low volume spray for killing adult
mosquitoes
Used as both Residual and Space spray

11. Paris green
Also called copper aceto-arsenite
Emerald green microcrystalline powder,
insoluble in water but soluble in other
organic solvents
Acts as stomach poison
Used as an alternative to DDT for killing anopheles larva
Dosage:
Sprayed as 2% dust over breeding places once a week for
effective control

12. Abate & Diazinon
Abate (Temephos)
Brown viscous liquid
Used extensively for control of A. Stephensi in well
Safe with domestic water
Dosage: < 1 ppm
Diazinon:
Volatile liquid
Having fumigant action
Dosage: 60-100 mg per sq.ft
More toxic than Malathion

13. Fenthion
Brown liquid & with some garlic smell
Also available in powder form as 20-40% strength
Dose: 100 mg per sq.ft residual sprays
Very powerful as a larvicidal
Dichlorovos
Highly volatile liquid
Kills by fumigant action
It can be mixed with solid like wax to make tablets from which it
slowly evaporates

14. Propoxur
Used as an alternative to DDT in areas
where resistance is developed
Synthetic pyrethroids
Used to reduce the crisis of natural
pyrethrum
e.g.: tetramethrin, resethrin, prothrin

15. Space spray
• Outdoor spraying of
insecticides to kill adult
insects.
Indoor Residual spray
• Involves coating the walls
and other surfaces of a
house with a residual
insecticide. For several
months, the insecticide
will kill mosquitoes and
other insects that come in
contact with these
surfaces.
https://www.youtube.com/watch
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https://www.youtube.com/watch?v=
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16. Insecticide formulations and
dosages for IRS in NVBDCP
S.No. Name of Insecticide Preparation of
suspension in
water
Dosage per
sq.metre of
active
ingredient
Residual
effect in
weeks
Area to be
covered by
10 lit.of
suspension
to get
correct
dosage
1. DDT 50% wp 1 kg/10 Lit 1 gm 10-12 500 sq.m
2. Malathion 25% wp 2 kg/10 Lit 2 gm 6-8 250 sq.m
3. Deltamethrin 2.5%
wp
400 gm/10 Lit 20 mg 10-12 500 sq.m
4. Cyfluthrin 10%wp 125 gm/10 Lit 25 mg 10-12 500 sq.m
5. Lambdacyhalothrin
10% wp
125 gm/10 Lit 25 mg 10-12 500 sq.m
6 Alphacypermethrin
5%wp
250gm/10 Lit. 25 mg 10-12 500 sq.m
7. Bifenthrin 10% WP 125g/10 litre 25 mg. 10-12 500 sq.m.

17. Insecticide Resistance
“Development of ability of insect to tolerate doses of toxicants
which would be lethal to majority of the individuals in normal
population of same species”
Biological or Genetic factors responsible
Prolong use in inadequate doses
Resistant to DDT & its analogue (OC) & HCH & its analogue
(OC)
Double resistance / Cross resistance
Use of OP compound in place of OC compound

18. TOXICITY OF
INSECTICIDE
ORGANOCHLORINE COMPOUND
ORGANOPHOSPHURUS COMPOUND

19. ORGANOCHLORINE COMPOUND
All are nerve poison & DDT is least toxic
Symptoms;
Nerve excitability, Tremors & Convulsion
Lethal doses:
1. DDT_ 250mg per kg of body weight
2. Gamma HCH_ twice toxic then DDT
3. Diedrine is 5-8 times more toxic then DDT
Treatment:
• Stomach washout
• Barbiturates

20. Organophosphorus compound
M/A:
Inhibition of cholinesterase enzyme which catalyses degradation of
acetyl choline in the synapse causing accumulation of same.
Symptoms:
Headache, giddiness, apprehension
Restlessness, cold sweating, salivation
Uncontrolled urination & defecation
Unconsciousness
Ataxia, Coma
Death

21. Treatment of OP poisoning
Immediate removal from the site of exposure
Identify the source of exposure (inhalation/contact )
Hospitalization of symptomatic patient
Drugs used:
Atropine
Pralidoxime
BZD

22. Rodents
Domestic rodents
Black rat(Rattus rattus)
Norway rat (R. Norvegicus)
House Mouse (Mus musculus)
Wild rodents
Tetra indica (natural reservoir of plague)
Bandicota benglensis
B. Indica
Millardia meltada

23. Characteristics of adult
No. R. Rattus
(House rate)
R. Norveygicus
(Sewer rat)
1 Body Slim and slender Heavy rather large
2 Nose Long and sharp Broad and blunt
3 Tail Longer than the
combined length of
head and body
Shorter than the
combined length of
head and body
4 Ears Large Small
5 Eyes Big and prominent Small

25. Diseases transmitted by rodents
No. Type Name of diseases
1 Bacterial Plague, Tularaemia, Salmonellosis
2 Viral Lassa Fever, Haemorrhagic fever,
Encephalitis
3 Rickettsial Scrub Typhus, Murine Typhus,
Rickettsial Pox
4 Parasitic Hymenolepis Diminuata,
Leishmaniasis, Amoebiasis,
Trichinosis, Chagas Disease
5 Others Rat bite fever, Leptospirosis,
Histoplasmosis, Ring Worm

26. Antirodent measures
1. Sanitation measures
2. Trapping
3. Rodenticides
4. Fumigation
5. Chemosterilant

27. 1. Sanitation measures
• Proper storage, collection and disposal of
garbage
• Proper storage of food stuffs
• Construction of rat proof buildings,
godowns and warehouses
• Elimination of rat burrows by blocking
them with concrete

28. 2. trapping
• Simple operation
• Temporary reduction
• No of traps should be at least 5% of the
human population
• Wonder trap develop by the Haffkine
Institute Mumbai can trap as many as 25
rats at a time
• It is the supplementary to the other
methods of rodent control

29. 3. Rodenticides
• Single dose rodenticides
1. Those require ordinary care
• Red squill
• Norbromide
• Zinc phospide
2. Those requiring maximal precautions
• Sodium fluorocetate
• Fluoroacetamide
• Strychnine
3. Too dangerous for use
• Arsenic trioxide
• Phosphorus

30. 3. Rodenticides
• Multiple dose rodenticide
• Warfarin
• diphacinone
• coumafuryl
• Pindone
• Commonly use poison is Barium
carbonate, Zinc phosphide
• Zinc phosphide is recommended for large
scale use

31. 4. Fumigation
• It is effective method of destroying both rats and
rat fleas
• Fumigants used in anti rat campaigns are calcium
cyanide (cyanogas/cymag), carbon disulphide,
methyl bromide, sulphur dioxide etc.
• Cyanogas is pumped into rat burrows by foot
pump called the “Cyanogas pump”
• After pumping 2 ounce of the poison burrows are
promptly sealed with wet mud
• On contact with moisture cyanogas powder gives
of Hydrogen cyanide gas

32. Cyanogas pump

33. 5. chemosteriliant
• Chemosteriliant is a chemical that can
cause temporary of permanent sterility in
either sex or both sexes
• Still in the experimental stage

34. Summary
1) Anti-Larval Measures: Use of Abate, Fenthion etc
2) Anti-Adult Measures
a) Residual spray ---------------- DDT, Malathion etc.
b) Space spray--------------------- Pyrethrum (2%)
3) Rodenticide: Zinc phosphide and Barium Carbonate

35. Thank You