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International Journal of Mosquito Research 2019; 6(2): 27-31
ISSN: 2348-5906
CODEN: IJMRK2
IJMR 2019; 6(2): 27-31
© 2019 IJMR
Received: 13-01-2019
Accepted: 16-02-2019
Bisu Singh
Department of Zoology, School
of Life Sciences, Sikkim
University, Sikkim, India
Jiwan Gurung
Department of Zoology, School
of Life Sciences, Sikkim
University, Sikkim, India
Aparajita Chakraborty
Department of Zoology, School
of Life Sciences, Sikkim
University, Sikkim, India
Correspondence
Bisu Singh
Department of Zoology, School
of Life Sciences, Sikkim
University, Sikkim, India
Study of the mosquito larval diversity in the
artificial breeding habitat of Gangtok, Sikkim
Bisu Singh, Jiwan Gurung and Aparajita Chakraborty
Abstract
With the growing urbanization, the number of discarded containers and construction of drains has
increased considerably in Gangtok which may provide a conducive breeding habitat for mosquito larva.
Therefore, the present study was undertaken to investigate the mosquito larval diversity in the artificial
breeding habitat of Gangtok. A random sampling was done from the discarded buckets, tanks, tyres,
drains at seven different sites during the months of July to October 2017. A total of 247 mosquito larvae
was collected from seven sampling sites. The species observed in the different sampling sites were Aedes
albopictus, Aedes atropalpus, Ochlerotatus japonicus, Culex pipiens, Culex territans, Ochlerotatus
taeniorhynchus, and Ochlerotatus trivittatus. Among the observed species Ochlerotatus japonicus was
found to have the maximum abundance (32%). Correlation analysis tests showed the significant positive
correlation between the larval abundance and the volume of water (r=0.94, P=0.002). As per the
Shannon-Wiener index, highest diversity was observed at Fifth mile (1.37) and least in Gangtok town
(0.44). Pielou’s Evenness index indicated that species were evenly distributed in all the sites except
Gangtok town (0.63). Bray-Curtis index revealed the highest species similarity between Ranipool and
Tadong (0.82). The present study gives elementary information about the species diversity of mosquitoes
in the artificial breeding sites of Gangtok. The presence of potent disease vectors like Culex and Aedes
shows the vulnerability of this region for the outbreak of mosquito-borne diseases in the near future as
Gangtok is a famous tourist destination.
Keywords: Artificial habitat, Gangtok, Mosquitoes
1. Introduction
Gangtok is the capital city of Sikkim and is a popular hill station of North East India. It has a
temperate climate throughout the year with an annual rainfall of about 2739 mm (Census of
India. Sikkim. 2011)
[7]
. As such, water gets accumulated in the containers scattered in
different localities which are being discarded by the locals and the tourists (Kumar et al. 2009)
[14]
. With the growing urbanization, the number of discarded containers is increasing day by
day in Gangtok which provides suitable breeding habitat for mosquitoes. Studies revealed that
with the extended urbanization around the world, preference of mosquitoes for artificial
containers for breeding has increased to a large extent, which implies that the distribution of
larval mosquitoes is greatly influenced by human ecology (Chen et al. 2009)
[8]
. Thus, many of
the studies have been conducted to investigate the mosquito larval diversity in artificial
breeding sites. Studies have reported that the species of mosquitoes such as Aedes aegypti,
Aedes albopictus, Aedes niveus, Culex quinquefasciatus, Anopheles and Culex generally breed
in artificial containers (Chen et al. 2009; Adeleke et al. 2008; Dass et al. 1998; Suganthi et al.
2014)
[8, 1, 10, 21]
. Further, it has been observed that in the urban areas the environment has a
major effect on the incidence of Aedes albopictus larvae (Li et al. 2014)
[15]
. In addition,
studies have also observed the existing and disappearing species of mosquitoes along with
their pattern of distribution (Asha et al. 2014)4
[4]
. It has been reported that artificial containers
provide a good habitat for the vector of Dengue (Rajesh et al. 2013)
[18]
. So far, the study of
mosquito diversity in the Himalayan region of Sikkim has been meagre. A survey conducted
on the haematophagous arthropods in the Himalayan regions of West Bengal and Sikkim
revealed the existence of 29 species of mosquitoes (Bhat 1975)
[6]
. Similarly, Aditya et al.
(2006) studied the mosquito larval habitats (temporary pools and cemented water storage
tanks) and their temporal variation in the town of Darjeeling, which revealed the existence of
four mosquito genera belonging to Aedes, Armigeres, Culex and Toxorhynchites with