Treehole mosquitoes
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Transcript of Treehole mosquitoes
ROLE OF TREE-HOLES AS IMPORTANT BREEDING SITES OF MOSQUITOES (DIPTERA: CULICIDAE) INCLUDING DISEASE VECTORS IN NORTH KERALA, INDIA
Sumodan, P.K and Jaseela, P.
P.G. Department of Zoology, Government College, Madappally, Vadakara- 673102
INTRODUCTION
Mosquitoes are the most important insect disease vectors responsible for about 2 million deaths annually
Of the 3000 known species about 100 are vectors
Mosquitoes breed in variety of breeding sites Aedes mosquitoes are container breeders Tree-holes are natural container breeding sites The present study was carried out to reveal the
significance of tree-holes as mosquito breeding sites
The study was conducted from June-December 2009
STUDY AREA
Vadakara Taluk (Kozhikode district)
METHODOLOGY
Trees were surveyed randomly for holes in three localities in Vadakara Taluk (Madappally, Mukkali and Chekkiad)
Tree-holes up to a height of 6 feet were surveyed for mosquito breeding
Water from the hole siphoned out using a plastic tube into containers
Samples transferred to the laboratory for mosquito emergence and identification
Identified under stereomicroscope using standard keys (Barraud, 1934)
COLLECTON
TREE HOLES
REARING
OBSERVATIONS & RESULTS
Total tree-holes surveyed: 100 Tree-hole with mosquito breeding : 100
(100%)
SPECIES DIVERSITY
Aedes albopictus -100% Heizmannia chandi- 90% Culex brevipalpis- 10% Armigeres subalbatus-10% Toxorhynchites splendens-15%
AEDES ALBOPICTUS
Vector of Chikungunya and Dengue Described as Culex albopictus by Skuse
(1894) from Calcutta
HEIZMANNIA CHANDI
Vectorial status- not known Described from Puthuppadi, Kozhikode
district in 1922 by Edwards
CULEX BREVIPALPIS
Vectorial status- not known Described as Stegomyia brevipalpis by Giles
in 1902 from Shajahanpur
ARMIGERES SUBALBATUS
Suspected vector of Wuchhereria bancrofti, Japanese Encephalitis and dog heart worm Dirofilaria immitis
Described as Culex obturbans by Walker (1860)
TOXORHYNCHITES SPLENDENS
Non-blood feeding species Larvae are predators of other mosquito
larvae Described as Culex splendens by Wiedemann
from Java in 1819
BREEDING PERCENTAGE
Aede
s al
bopi
ctus
Heizm
anni
a ch
andi
i
Arm
iger
es sub
alab
atus
Culex
bre
vipa
lpis
Toxo
rhyn
chite
s sp
lend
ens
0
30
60
90
BREEDING ABUNDANCE BASED ON EMERGENCE
Aedes albopictus – 56.5% Heizmannia chandi-35.8% Culex brevipalpis- 2.8% Armigeres subalbatus-3.2% Toxorhynchites splendens-1.8%
SPECIES ABUNDANCE
Aedes albopicusHeizmannia chandiCulex brevipalpisArmigeres sub-albatusToxorhynchites splendens
DISCUSSION 100% of tree-holes were positive for mosquito-
breeding. Hence it is an important category of breeding sites
Aedes albopictus, the vector for Dengue and Chikungunya was found breeding in all tree-holes surveyed. They were also the most abundant species.
Toxorhynchites splendens, the predator mosquito was also found breeding in 15% of the tree-holes, which may be used as a control agent
The study emphasizes the need of including tree-holes in the anti-mosquito strategy of public health authorities
More research is needed to formulate effective control strategies in these neglected breeding sites.
Any questions?
Thank you