Systematic Position of Mosquito

• Phylum- Arthropoda ( organisms with jointed appendages and exoskeleton)

• Class- Insecta ( 3 pairs of legs, Head Thorax, abdomen)

• Order-Diptera ( Two-winged flies)

• Family- Culicidae (Mosquitoes-

• Well-developed forward projecting proboscis

• Characteristic wing venation

• Presence of fringes on the posterior margin of wing.

Mosquito Diversity

• More than 3500 species of mosquito in the

world.

• They are grouped under two Sub-familes

Anophelinae(Anopheles) and Culicinae(Culex,

Aedes, Mansonia, Armigeres, Toxorhynchitis)

• There are 113 genera

കകൊത ക ക എവ കെകെ ്ൊാം ?

• ഉഷ്ണമേഖ , േ മതൊഷ്ണ മേഖ ,ആ ട്ട ക് സ ക്ക എന്ന വ െങ്ങ കൊണ ന്ന

• അന് ൊ ട്ട ക്കെ ാം േറ്റു ച ദ്വ പ ക ാം ഇ ്.

• സേ ദ്ദ് ന പ്പ ന ന്ന ാം 5500 േ .ഉെ ത്ത ാം 1250 േ തൊഴ്ചെ ള്ള

• ഖന ക ാം കകൊത ക ക കൊണ ന്ന .

Mosquito Species Genus World India

No. of species

Major vector No. of species

Major vector

Anopheles 422 60 58 6

Aedes 888 25 111 2

Culex 715 12 57 4

Mansonia 23 7 4 2

Total > 3500 species under 113 genus

255 species under 17 genus

Vector borne diseases Disease Pathogen Vector Incubation

Malaria Plasmodium vivax,

Pl. falciparum

Anopheles 14(6-17)days

12(9-14) days

Dengue fever Group B Flavivirus Aedes aegyptii

Aedes albopictus

5- 7 days

Chikungunya Alphavirus do 1-12 days

Japanese

encephalitis

Flavivirus Culex vishnui gp

Mansonia

5-15 days

Filariasis Wuchereria

bancrofti

Brugia malayi

Culex

quinquefasciatus

Mansonia

Vector borne diseases Disease Pathogen Vector Incub.

Scrub typhus Orientia

tsutsugamushi

Leptotrombidium

(mite)(chigger

mite)

Larvae transmit

disease to man,

Rodents-reservoir

10-12

days

Cutaneous

Leishmaniasis

Leishmania tropica Sand fly-

Phlebotomus

papatasi

Adult suck blood

and transmit

10

days

or

more

Visceral

leishmaniasis

(Kala azar)

Leishmania

donovani

Phlebotomus

argentipes

do 2week

s-2yrs

Kyasanur

Forest Disease

Flavivirus Hard tick

Haemophysalis

spinigera,

H. kysanurensis

First reported from

from Kysanur

forest,Karnataka-

Shimoga district-

monkeys involved

3-8

days

Leptospirosis Leptospira(spiroch

ete bacteria)

Rats, domestic

animals

4-19

days

Eggs

Adult mosquito

Larva

MOSQUITO LIFE CYCLE

Pupa

7-10 Days

Anopheles -Culex- Aedes

Larvae of Anopheles, Aedes and Culex

mosquitoes

Antenna of male and female mosquito Antenna of male mosquito is feathery and that of female is hairy

Head of Culex: Male and Female

Head of Anopheles: Male and Female

Anopheles

larva Adult

Anopheles

Culex

• State the alternative strategies

• List advantages & disadvantages of each

• State cost of each option

Aedes

larva Adult

Egg cluster & larva of Mansonia

Adult Mansonia

Anopheles - adult

Culex - adult

Aedes aegyptii

Important vectors found in Kerala

Anopheles Culex Aedes

Haemophysalis P. argentipes

Ixodus scapularis-

Ticks

• Flight range is 2 to 9 miles (1 mile = 1.6 kms)

• Breeding places: dirty & polluted water

• Resting place: indoors on walls, underneath furniture

• Biting time is midnight

CULEX

• Very poor flight range:100-400 meters

• Breeding place: artificial collection of water like water in broken pots

• Most abundant during rainy season

• Biting time: daytime

AEDES

• Flight range:2-3 miles

• Breeding places: clean water

• Biting time: night ANOPHELES

Larval indices of Aedes

1. House Index (HI) - Percentage of houses

positive for larvae of Aedes.

2. Breteau Index (BI) - Number of positive

containers for Aedes per 100 houses.

3. Container Index (CI) - Percentage of

containers positive for Aedes breeding.

4. Pupal Index (PI) - Number of pupae per 100

houses.

Epidemiological interpretation of Indices

.

Vector Indices High risk of

transmission

Low risk of

transmissiom

House Index >10% <1%

Breteau Index >50 <5

Landing Rate >2 p m h <0.2 p m h

54

55 Dr. Reena K J

Culex quinquefasciatus

Mansonia annulifera

Pistia plant

Rice Field

Culex vishnui subgroup

Shallow Ditches at Field

Unused boat

Open Sintex tanks

Well with motor pump

Overhead tanks

Ground level tank

Open Overhead Tanks

Bio gas plant

Loom tray

Pineapple - axils

Rubber estate

Cocoa shells

Colocasia

Polythene pond

DRY DAY OBSERVATION

• Monitoring of vector indices- Aedes indices

• Regular & continuous SR - identification & elimination of breeding sources

• Biological control –guppy fishes, biolarvicides

• Environmental - filling up of ditches

• Minor engineering works- Covering of water tanks, repair of septic tanks, netting of vent pipes etc

• Chemical control -Temephos, Diflubenzuron, MLOs, Neem cakes etc.

II. IVM- Larval control

II. IVM- Adult mosquito control

Chemical - Epidemic/Emergency situations

• Thermal fogging - Outdoor -technical malathion.

• ISS- 2% pyrethrum extract for killing infected mosquitoes.

• Commercial- Finit , Hexit ,Hit Baygon

• Done within 24-48 hours of reporting of a case.

• Indoor residual spray (IRS) using synthetic pyrethroids done within 7-10 days of reporting of a malaria case.

• Mosquito samples to VCRC, KTM for virus isolation.

80

INDOOR RESIDUAL SPRAY-

MALARIA

II. IVM- Personal protective measures

• Screening of windows and doors with mosquito meshes

• Insecticide treated bed nets.

• Repellents as coils, aerosols, creams etc.

• Wearing of long sleeved dresses.

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