by- Dr. Avinash Banjare Dr. Dharmaraj Nag

1. Definition
Study of arthropods of medical importance

4. TRANSMISSION OF
ARTHROPOD BORNE
DISEASES
DIRECT
CONTACT
MECHANICAL
TRANSMISSION
BIOLOGICAL
TRANSMISSION

5.  Direct contact – directly transferred from man to
man through close contact
eg. Scabies & pediculosis
 Machenical transmission- transmitted mechanically
by vectors
eg – diarrhoea, dysentry etc
 Biological transmission- disease agent undergoes
developemental changes with or without
multiplication in vectors

6. 3 types of biological transmission
I. Propagative
only multiplication NO cyclical change
eg –plague bacilli in rat flea
ii. Cyclo-developmental
only cyclical changes NO multiplication
eg- Filarial parasite in culex mosquito,
iii. Cyclo-propagative
BOTH multiplication n cyclical changes
eg- malarial parasite in anopheles mosquito

7. MOSQUITO
 4 imp groups of mosquito in India
1. Anopheles
2. Culex
3. Aedes
4. Mansonia

9.  Body consists of 3 parts
A. HEAD- i. A pair of large compound eyes
ii. A long proboscis with which mosquito
bites
iii. A pair of palpi on either sides of proboscis
iv. A pair of antennae [male-bushy . Female – less
bushy]
B. THORAX- i. A pair of wings dorsaly
ii. Three pairs of legs ventrally
C. ABDOMEN- ten segments [last 2 modified to form
external genitalia]

11. LIFE HISTORY

13.  ANOPHELES
Species
An. culicifacies (cause RURAL MALARIA)
An. fluviatilis (found in FOREST & FRINGES)
An. stephensi (cause URBAN MALARIA )
An.dirus (found in North east states)
An. minimus etc
Diseases- malaria
filaria[outside India]
 Sits at 45 degree
 FRESH WATER breeding

17.  CULEX ( nuisance mosquito)
species -
Culex fatigans (C.quinquefaciatus)
Diseases-
. Bancroftian filariasis
. JE
. Westnile fever
- Rapid urbanization and industrialization without adequate
drainage are responsible for its spread
- Breeds in dirty water collection
- Flight range – 11kms
- HUNCHBACK appearance

20.  AEDES
White stripes on black body – so also known as Tiger
mosquito.
Species
. Aedes aegypti
. Aedes vittatus
. Aedes albopictus
Diseases
Dengue
DHF
Yellow fever
Filariasis outside India

22. Abundant during rainy season
 breeds in artificial accumulation of water eg . Tin
,broken bottles etc
Lays eggs singly CIGAR shaped
Bites during day time
Flight range 100meter
 Aedes aegypti INDEX- % House showing showing
breeding of Aedes larva
- upto 400m area around port
- should be less than 1%

23.  FEEDING HABIT
female – Heamatophagous( require blood meal)
male – plant juice (never bite)
 TIME OF BITING
mostly evening or early part of night
 RESTING HABIT
rest during day in dark and cool corners
 BREEDING HABIT
Anopheles –clean water
Culex- dirty polluted water
Aedes- artificial water collection
Mansonia- water containing aquatic vegetaion

24.  HIBERNATION
Adult mosquito hibernate in unfavourable conditions like
extreme winter
 DISPERSAL
Generally do not fly far from breeding place EXCEPT Culex ( up
to 11kms)
 LIFE SPAN
varies from 8 to 34 days
influence by temperature and humidity
males are short lived

25. MOSQUITO CONTROL MEASURES
 ANTI LARVAL MEASURES
a. Environmental control
b. Chemical control
c. Biological control
 ANTI-ADULT MEASURES
a. Residual sprays
b. Space sprays
c. Genetic control
 PROTECTION AGAINST MOSQUITO BITES
a. Mosquito nets
b. screening
c. Repellents

26. ANTI LARVAL MEASURES
 A- ENVIROMENTAL CONTROL
 most important step – to eliminate breeding places
(source reduction)
 Source reduction comprises minor engineering methods
such as filling, levelling and drainage of breeding places
and water management.
 B- CHEMICAL CONTROL
 commonly used larvicides
a. Mineral oil
b. Paris green
c. Synthetic insecticides

27.  Mineral oils
When applied on water oil spreads and forms a thin film which cuts
off the air supply to the mosquito larvae and pupae. eg mosquito
larvicidal oil, fuel oil,diesel oil etc.
 Paris green
- Chemical composition-copper acetoarsenite.
- Acts as stomach poison.
- Mainly kills anopheles larvae because they are surface feeders.
 Synthetic insecticides
-examples of most effective organophosphorous larvicides
Fenthion
Chlorpyrifos
Abate

28. C- BIOLOGICAL CONTROL
-some fish feed readily on mosquito larvae.
Eg.Gambusia affinis
Lebister reticulatus

29. ANTI ADULT MEASURES
A- RESIDUAL SPRAYS
-Eg.DDT[most commonly used]
Malathion
Propoxur
Lindane
B- SPACE SPRAYS
-Sprayed as mist or fog
-Pyrethrum Extract:
Pyrethrin(active principle)
-it acts as nerve poison
C- GENETIC CONTROL
-Sterile male technique
-Cytoplasmic incompatibility
-chromosomal translocations
-sex distortion etc

30. PROTECTION AGAINST MOSQUITO
BITES
 A- MOSQUITO NETS
>size- 0.0475 inch diameter
>no of holes in one square inch-150
 B- SCREENING
>Screening of the building is done with copper and bronze
gauge.
>costly but excellent results.
 C-REPELLENTS
>Eg.Diethyltoluamide(DEET)-most common
Dimethyl carbate
Indalone
>short duration of protection

31. HOUSE FLIES
 Important species:
Musca domestica-most common
M. vicinia
M.nebulo etc
General characters
 Mouse grey in colour
 Body divided into
 Head
 Thorax
 Abdomen
 HEAD:A pair of antennae
 A pair of large compound eyes(male-close together;female-set
apart widely)
 A retractile proboscis(sucking liquid foods)

32.  THORAX:Marked with 2-4 dark longitudinal stripes
which is characteristic of genus musca
 A pair of wings
 3 pairs of legs
 covered with numerous short and stiff hairs
known as Tenent Hairs
 ABDOMEN:segmented and shows light and dark
markings

35.  LIFE HISTORY
EGG :The female lays from about 120-150 eggs at one
sitting in moist decaying organic matter
LARVA:Also known as Maggot.They are white
segmented and footless with a narrow anterior end
and broad posterior end.
PUPA:dark brown and barrel shaped
ADULT:Life span upto 15-25 days

37.  BREEDING HABITS:
-Fresh horse manure
-Human excreta
-Manure of other animals etc
 FEEDING HABITS:
-can NOT eat solid foods.it vomits on solid food
to make a solution of it and sucks in a liquid state.
 RESTLESSNESS:
-help in spread of infection mechanically.

38.  RESTING HABIT:
-Rest on vertical surfaces and hanging objects.
 DISPERSAL:
-Normally remain close to breeding places but they
disperse frequently upto 4 miles.

39.  TRANSMISSION OF DISEASE:
Disease transmitted
Typhoid and Paratyphoid fevers
Diarrhoeas and dysentry
Cholera
Gastroenteritis etc..
MODE OF TRANSMISSION:
1. Mechanical transmission
2. Vomit drop
3. Defecation

40. CONTROL MEASURES
1. ENVIRONMENTAL CONTROL
 Storing garbage & kitchen waste in bins with tight lids
 Provision of sanitary latrines
 Stopping open air defecation etc
2. INSECTICIDAL CONTROL
a) Residual sprays- DDT,lindane,malathion,fenthion etc
b) Space sprays- pyrethrin , DDT,HCH
c) Larvicide- diazinon,dimethoate

41.  3.FLY PAPERS
- contains resin and castor oil
- applied to the stripes of wire and hung up in places
where flies abound
 4.PROTECTION AGAINST FLIES
- screening of house, hospitals, food markets etc
 5.HEALTH EDUCATION
-Health education regarding disease transmission
and fly awareness

42. SAND FLY
BODY
A. HEAD
 Bears a pair of long, slender and hairy antennae; palpi
and a proboscis.
B. THORAX
 Bears a pair of wings and 3 pairs of legs.
 Wings are densely hairy and legs are very long out of
proportion of body.
C ABDOMEN
 Has 10 segments.
 Covered by hairs.

44.  DISTINGUISHING FEATURES FROM MOSQUITO
a) Size: Smaller than mosquito.
b) Wings: Wings upright and lanceolate in shape.
Bifurcated vessels on wings.
c) Legs: Longer as compared to size of body.
d) Hairs: Hairy insect.
e) Hopping: Hops about an dont fly by choice.

46.  HABITS
 Only female bites during nights.
 Bite is irritating & painful.
 Dark place holes, crevices in wall, trees etc..
 DISEASE TRANSMITTED
SPECIES DISEASE TRANSMITTED
Phlebotomus argentipes Kala-azar
Phlebotomus papatasii Sandfly fevers
Oriental sore
Phlebotomus sergenti Oriental sore
S. punjabensis Sandfly fever

48. CONTROL OF SANDFLY
A. INSECTICIDES – Spraying with DDT & Lindane.
B. SANITATION- Removal of shrubs and vegetation.
Filling u of cracks and crevices in
walls and floors.

49. TSETSE FLY
 Only found in African continent.
 Attack generally during travelling.
 Causes- Sleeping sickness/trypanosomiasis
 LIFE CYCLES:
1.Larva
2.pupa
3.Adult

51. CONTROL MEASURES
A. INSECTICIDES: DDT,Dieldrin
B. CLEARING OF VEGETATION
C. DESTRUTION OF WILD ANIMALS
D. GENETIC CONTROL: Sterile male tech.

52. BLACK FLY
 Vectors of Onchocerciasis in Africa,Mexico,Central
and South America.
 Size too small but wings are comparatively large.
 Life cycle:
1.Egg
2.Larva
3.pupa
4.Adult

54. CONTROL MEASURES
 Abate:Acts as Larvicidal
 Adult: Uncontrollable due to high flying speed.

55. LICE
TYPES
1. Head louse (Pediculus capitis)
2. Body louse (Pediculus corporis)
3. Pubic or crab louse ( Phthirus pubis)
HEAD AND BODY LOUSE
 IDENTIFICATION FEATURES
 Body is dorsoventraly flattened
 Body - Head
Thorax
Abdomen
 Thorax- Square shaped
 Elongated abdomen- 9 segments
 Last segment – (Female-Bilobed Male- Pointed)

57.  LIFE CYCLE
 Egg (Nit)
 Nymph
 Adult
DISEASE CAUSATIVE AGENT
1.Epidemic typhus Rickettssia prowazeki
2.Relapsing fever Borrelia recurrentis
3.Trench fever R quintana
4.Dermatitis due to scraching and seconadry
infection

60. CRAB LOUSE
 IDENTIFICATION FEATURES
 Dorsoventrally flattened body
 Square shaped body
 Large legs
 Large claws to hold onto hair strand
 Appears as a crab
 Cause no disease

62. CONTROL MEASURES
INSECTICIDAL CONTROL
 0.5% MALATHION lotion
PERSONAL HYGIENE
 Daily bathing
 Freq hair wash
 No sharing of combs etc

63. FLEAS

64. RAT FLEA
IDENTIFICATION FEATURES
 Bilaterally compressed body
 Body covered with bristles
 Body
head
Thorax
Abdomen
 Head bears piercing mouth parts
 Thorax – 3 pairs of strong legs

67. Life cycle
1. Egg
2. Larva
3. Pupa
4. Adult
 Habits
 Both male female suck blood
 Cant fly hops only

69.  Disease transmitted
 Bubonic plague
 Endemic typhus
 Chiggerosis
CONTROL MEASURES
 INSECTICIDES-
DDT dust
Diazinon spray
Malathion spray
 REPELLENT
Diethyl toluamide
 Rodent control

70. TICK
 TYPES
Hard tick (ixodidae)
Soft tick ( argasidae)
Identification features of HARD TICK
 Oval body
 No clear distinction of body
 4 pairs of leg
 NO antennae
 Covered with scutum
 Head visible from above

74. MITE
TROMBICULID MITE
 Spider like arthropod
 Vectors of scrub typhus in asia and south pacific
LIFE CYCLE
 Egg
 Larva
 Nymph
 Adult

76. CONTROL MEASURE TICKS & T. MITE
 INSECTICIDAL CONTROL
DDT, malathion ,lindane etc
 ENV CONTROL
Cracks and cervices are filled up
 PROTECTION OF WORKERS
Protective clothing with repellents

77. ITCH MITE
 Globular body.
 No demarcation into cephalothorax or abdomen.
 Four pairs of legs-
Two front pairs bear suckers
Two back pairs are long slender
LIFE CYCLE
 Egg
 Larva
 Nymph
 Adult

80.  Causes SCABIES; first disease of mankind with known
cause.
 Scabies leads to dermatitis due to secondary
infections.
PARTS AFFECTED
1. Hands and wrist
2. Extensor aspects of elbows
3. Axillae
4. Buttocks
5. Lower abdomen etc

82. CONTROL MEASURES
 All the family members must be treated
simultaneously.
 Before application of Sarcopticides thorough scrub
with soap and hot water.
 Sarcopticides used-
1.Benzyl benzoate
2.Gamma HCH
3.Tetmosol solution
4.Sulphur ointment

83. INSECTICIDES
 Substances which are used to kill insects.
 PESTICIDE is general term includes insecticide, fungicide
herbicide, rodenticide etc.
 CLASSIFICATION : 3 groups
1. Contact poison: kill insect primarily by contact
Eg. Pyrethrum, DDT,HCH, dieldrin etc..
2. Stomach poison : when ingested cause death of insect
Eg . Paris green ,sodium fluoride
3. Fumigants: give off vapours which have lethal effect on
insects
Eg. Sulphur di oxide

85. DDT
 Dichloro diphenyl trichloro ethane
 Synthesised by ZIEDLER
 PROPERTIES:
 White amorphous powder with mild unpleasant smell.
 Insoluble in water but dissolve in organic solvent.
 Most active fraction of DDT : para para isomer.
 ACTION:
 Contact poison acts on nervous system of insects .
 Permeates into insect through cuticle causing paralysis of
wings and legs, convulsion n finally death.
 Take several hours to kill.

86.  APPLICATION :
 As a residual spray.
 Doses: 100-200mg/sq foot area
 As a dust: 5-10% for control of lice,tick,fleas.
 DISADVANTAGE:
 Adverse effect on certain wild animal but the benefits
far outweigh the hazards so it is most widely used
insecticide.

88. HCH/BHC
 Hexa chloro cyclohexane
 Benzene hexa chloride
 Gammexane
 Michael faraday
 PROPERTIES:
 White or chocolaty colour with musty odour.
 Irritating to eye nose skin.
 Most active constituent: Gamma isomer.
 Pure HCH containing 99% gamma isomer is called
LINDANE OR GAMMA-HCH.

89.  ACTION:
 Contact poison
 Residual action is shorter than DDT.
 APPLICATION:
 Same as DDT.
 Dose : 25-50mg/sq feet

90. MALATHION
 Least toxic among all OP compounds.
 Yellow or clear brown liquid with unpleasant smell.
 Used as water dispersible powder.
 100-200mg/sq foot
ABATE(TEMEPHOS)
 OP compound ;brown viscous liquid soluble in
petroleum solvent.
 Due to its less toxicity used for the control of
Anopheles in domestic wells.

92. DIAZINON
 Liquid volatile product kills as CONTACT poison and
as fumigants
 Effective against DDT resistant insects.
 60-100mg/sq foot

93. FENTHION
 Brown liquid with garlic smell.
 Insoluble in water
 As effective as DDT
 As residual sprays with dose 100mg/sq foot
 Highly effective against culex.

94. PROPOXUR
 New carbamate insecticide.
 Effective against anopheles which are resistant to DDT
and dieldrin.

95. PYRETHRUM
 Insecticide of vegetable origin extracted from flowers
of Chrysanthemum
 4 active principle; PYRETHRINS 1 and 2
 Cinerins 1 and 2
 These all are NERVE poisons
 The ready to spray solution contains 0.1% prethrin.
 Highly effective against adult mosquitoes.
 Disadvantage:
 Does NOT possess residual action.

97.  Synthetic pyrethroids
 Replaced the natural pyrethrins
 10 times more effective.
 Eg. Resethrin,proparthin
MINERAL OILS
 Oils like kerosene,crude oil extensively used to kill
mosquito larvae and pupae.
 Oil suffocate and poison the aquatic stages of
mosquito.

98. PARIS GREEN
 Copper aceto arsenite.
 Green micro crystalline powder soluble in ammonia
and concentrated acids.
 Contains more than 50% arsenious oxide
 Stomach poison used against anopheles larvae.

99. RODENTICIDE
 2 types
 Single dose/acute: lethal to thr rat after single dose.
 Multiple dose cumulative : require multiple feeding.
ACUTE/SINGLE:
 Barium carbonate: white tasteless powder mixed with wheat or rice
flour. Takes 2-24 hr to kill.
 Zinc phosphide: more efficient rodenticide.
 Mixed with rice and wheat flour. 3hr to kill.
 Because of its good safety record,low cost and high effectiveness used
widely.

101. MULTI DOSE:
 Warfarine
 Slow death 4-10 days
 Fumigation :
 Effective method of killing both rats and rat fleas
 Eg calcium cyanide( cyano gas ),
carbon di sulphide
sulphur di oxide etc..
 Cyano gas is extensively used in India for fumigation of rat
burrows.
 Cyano gas powder gives off hydrogen and cyanide which is
lethal to rat and rat fleas.