Vol.3, No.4A, 11-16 (2013) Open Journal of Animal Sciences
http://dx.doi.org/10.4236/ojas.2013.34A1003
Distribution patterns and relationship between
elevation and the abundance of Aedes aegypti in
Mojokerto city 2012
Zulfaidah Penata Gama1,2*, Nobukazu Nakagoshi1, Madaniatul Islamiyah2
1Graduate School for International Development and Cooperation (IDEC), Hiroshima University, Kagamiyama, Japan;
*Corresponding Author: [e-mail]
2Department of Biology, Faculty of Science, Brawijaya University, Malang, Indonesia
Received 30 July 2013; revised 2 September 2013; accepted 22 September 2013
Copyright © 2013 Zulfaidah Penata Gama et al. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Mosquitoes are one of the insects that have an
important role as vectors of disease agents. The
diseases transmitted by mosquitoes are still
public health problems in Indonesia especially
in East Java Province, for example, Dengue
Hemorrhagic Fever (DHF). DHF is a very alarm-
ing disease because the occurrence of this epi-
demic is no longer just confined to certain geo-
graphic locations. At present, Mojokerto is a
district in East Java region known as endemic
for DHF in Indonesia. The number of cases in
this district tends to rise and expand distributed.
The spread pattern of dengue cases in this dis-
trict is not certainly known. The aim of this re-
search is to determine the distribution pattern of
mosquitoes and its relationship between eleva-
tion and density of Aedes aegypti in the Mo-
jokerto district that caused dengue virus trans-
mission. Sampling was conducted at two loca-
tions in the Mojokerto district, in the urban and
rural, namely Prajurit Kulon for urban and Dlan-
ggu for rural. We used survey for mosquito lar-
vae by WHO standard and for mosquito eggs by
ovitrap. The coordinates of sampling locations
are recorded using GPS and then identification
of mosquitoes is performed at the Laboratory of
Ecology and Animal Diversity, University of Bra-
wijaya. Quantitative data were analyzed to de-
termine the abundance, relative abundance, fre-
quency, relative frequency and IVI (Importance
Value Index). Mosquito distribution patterns
were analyzed with Morisita index. The research
findings indicated that there are five mosquitoes
species consisted of Aedes aegypti, Aedes al-
bopictus, Aedes laniger, Culex bitaeniorchyn-
chus and Culex quinquefasciatus. Aedes aegypti
is the dominant species in urban area while
Culex quinquefasciatus is th e dom inant species
in rural area. Morisita index showed that mos-
quito dispersal on patterns in Mojokerto district
is uniform. The elevation of the area and density
of Aedes aegypti has a positive correlation.
Keywords: Aedes aegypti; Distribution Pattern;
Elevation; Mojokerto
1. INTRODUCTION
Dengue hemorrhagic fever is one of the most impor-
tant viral diseases in the world. Dengue viruses are
among the most widely distributed and significant ar-
thropod-borne viruses (Arboviruses) affecting humans.
DHF potentially affects 2.5 billion people and more than
100 tropical and sub-tropical regions of the world [1,2].
Dengue is one of the most serious health problems in
Indonesia, with Aedes aegypti acting as the vector [3].
DHF outbreaks have been recorded in Surabaya area
since 1986. DHF virus is transmitted to human through
the bites of infective female Aedes sp. (Diptera: Culici-
dae) mosquitoes [4].
Aedes aegypti often breeds in water storage containers
used by households without tap water supply and occurs
in high numbers even in dense urban areas [5]. These
mosquitoes are well adapted to the urban environment
and successfully breed in containers where water is al-
lowed to accumulate, such as discarded can, bottles,
plastic containers, and tires. Aedes aegypti is particularly
susceptible to climate variability and climatic change.
Changes in mean climate conditions and climate vari-
ability also can affect human health via indirect pathways,

Z. P. Gama et al. / Open Journal of Animal Sciences 3 (2013) 11-16
12
especially in the changing of biological and ecological
processes that influence infectious disease transmission
and food yields [6].
Global emergence and resurgence of dengue can be at-
tributed to multiple facto rs including urbanizatio n, trans-
portation and changes in human migration and behavior,
resulting in dengue increase as the second most impor-
tant vector-borne disease, after malaria, in term of human
morbidity and mortality [2]. It also occurred in East Java,
since it has been discovered in Surabaya, and the number
of cases tends to rise and expand in distribution. This
condition is closely related to the increased mobility of
the population in line with the fluent transport links and
the spread of dengue virus and mosquitoes in various
regions in Indonesia [7]. Environmental circumstance
strongly controls the geographic distribution and abun-
dance of Aedes aegypti.
Mojokerto is one of the cities in East Java that has en-
demic DHF. Based on the DHF case incidence data from
2008 to 2010, it was ob tained from P2PL of DHF. Health
Department of East Java Province showed that Mo-
jokerto district still had House Indices (HI), Containers
Indices (CI), and Breteau Indices (BI) quite high at 35%,
27.3% and 42.86% respectively [8]. Therefore, the ob-
servation was undertaken to determine the distribution
pattern of Aedes aegypti and risk factors of DHF between
regency and cities in Mojokerto 2012 and correlation
between elevation of sampling location and distribution
of mosquito.
2. MATERIALS AND METHODS
2.1. Study Area
Mojokerto District is located between 112˚26'01" East
longitude and 7˚27'59" South latitude in East Java Prov-
ince (see in Figure 1). Mojokerto’s territory is 872 km2,
located between 15 m and 3156 m above sea level. The
Brantas River divided it into north and south regions.
The district shares the boundary with Gresik and La-
mongan district in the north, with Malang district in the
south, with Sidoarjo and Pasuruan in the east, and with
Jombang distrist in the west. South Region has several
mountains, which includes Welirang Mountain (3156 m),
Anjasmoro Mountain (2277 m) and Penanggungan
Mountain (1693 m). Based on BPS [9] showed that the
population of the district is about 1,014,785. Many of
them earn their living as small farmers and craftsmen
(consisting shoemakers, furniture makers, and souvenir
Figure 1. Study site.

Z. P. Gama et al. / Open Journal of Animal Sciences 3 (2013) 11-16 13
makers). This area was selected as the study site based
on the results of the previous research that it was the one
of major DHF epidemic foci in Indonesia. The DHF in-
cidence was recorded at the district level (lattice data).
2.2. Data Collection
Sampling was carried out in urban and rural area of
Mojokerto District. Selected area of the urban is Prajurit
Kulon while the selected rural is Dlanggu. Each area was
taken three villages, namely are Surodinawan, Blooto,
Kranggan villages for u rban and Mojokarang, Segun ung,
Kalen for rural. Each village location in the five-p oint set
was sampled.
2.3. Capturing Larvae of Mosquito
Random coordinates were selected for five sampling
points in each village site using a topographical map
broken into 1-m2 grid squares. Coordinates were rese-
lected if they fell inside inaccessible areas (e.g., in the
middle of ponds), or inside unsecured areas (e.g., on
public roads), or there were located within 30 m of other
coordinate [10]. Larval sampling method with a dipper
from various places such as mosquito breeding places in
the house that shelters consisting of a water bath tubs,
tubs toilets, drinking water containers, jars, bowl of water,
and a bucket. Mosquito breeding places outside the home
such as drums, cans, bottles, pot scrap decorative plant
pots filled with rainwater. Observation of the presence or
absence of mosquito larvae was carried out for 4 days.
2.4. Capturing Egg of Mosquito
The capture of the eggs laid by the mosquito is col-
lected in a plastic cup that was given water. The ovitrap
was placed on each house is only one piece. Ovitrap dis-
carded and replaced by new water when sampling egg of
mosquito are conducted in each location. The number of
eggs were calculated after they hatched become mos-
quito larvae.
2.5. Statistical Analysis
Data analysis was performed to test the correlation
between elevations of each sampling location and the
number of mosquitoes in Mojokerto District.
Determining the Importance Value Index (IVI)
Important Value Index (IVI) is used to establish the
dominance of a species to other species or in other words
the importance of describing the position of a species in
the ecological community. Calculate Frequency, Abun-
dance, Relative Frequency and Relative Abundance,
analysis using Microsoft Excel 2007. IVI (Importance
Value Index) can be determined by:
IVIRelative AbundanceRelative Frequency=+
2.6. Determination of Population
Distribution by Morisita Index
The distribution pattern of population can be deter-
mined by using the Morisita index by the following for-
mula:
()
2
11
i
iXN
I
dn
NN
=−=
−

N = total number of individual in the plot
n = number of plots
2
i
X
= the square of the number of individuals in the
plot to I [11]
Morisita index is a statistical measure of dispersion of
individuals in a population. It is used to compare overlap
among samples [8]. This formula is based on the as-
sumption that increasing the size of the samples will in-
crease the diversity because it will include different
habitats (i.e. different faunas). The standardized Morisita
index was used to assess the spatial p attern (i.e. clumped,
random or uniform) of the most abundant species. The
index was calculated as:
Va l u es o f Id = 1 indicate a random dispersion Values
of Id < 1 indicate a uniform dispersion Values of Id > 1
indicate a clumped dispersion
3. RESULTS
Mosquitoes were found in Mojokerto district consist
of five species: were Aedes aegypti, Aedes albopictus,
Aedes laniger, Culex bitaeniorchynchus and Culex quin-
que fasci atus .
Table 1 showed that mosquitos larvae in the urban
area (Prajurit Kulon) were encountered are Aedes aegypti,
Aedes albopictus and Culex quinquefasciatus. Aedes
aegypti is the dominant species as the highest IVI value.
The capturing egg of mosquitos using ovitrap in Ku lon
Prajurit (the urban area) show ed that it found three types
of mosquitoes. These species are Aedes aegypti, Aedes
albopictus and Culex quinquefasciatus (see in Table 2).
Pearson correlation was conducted in Mojokerto Dis-
trict, 2012 related to elevation of each area to the density
Table 1. Mosquito larval abundance and composition in Mo-
jokerto district.
Abundance (individu)
Species Urban Rural
Aedes aegypti 52 50
Aedes albopictus 49 62
Aedes laniger - 7
Culex bitaeniorchynchus - 48
Culex quinquefasciatus 39 104

Z. P. Gama et al. / Open Journal of Animal Sciences 3 (2013) 11-16
14
Table 2. Abundance and composition of mosquitoes were cap-
tured with ovitrap.
Abundance (individu)
Species Urban Rural
Aedes aegypti 54 55
Aedes albopictus 20 22
Culex quinquefasciatus 50 99
of Aedes aegypti measures. The results showed that ele-
vation of the area and density of Aedes aegypti has a
positive association (see Table 3).
Figure 2 illustrates that Aedes aegypti with Impor-
tance Value Index (IVI) of 70.48% followed by Aedes
albopictus (68.33%) and Culex quinquefasciatus (61.19%).
Aedes aegypti is more often found in urban areas (Pra-
jurit Kulon) than rural area (Dlanggu Subdistrict). There
is also a similar result on the previous studies stated that
Aedes aegypti is more dominant than Aedes albopictus
[12].
Species of mosquitoes were found in the Dlanggu su b-
district illustrated in Figure 3, they are Aedes aegypti,
Aedes albopictus, Aedes laniger, Culex bitaeniorynchus,
Culex quequinfasciatus. Culex quinquefasciatus has the
highest IVI value (59.8%) than other species, and there is
followed by Aedes albopictus (44.31%), Aedes aegypti
(39.88%), Culex bitaeniorynchus (39.14%), Aedes lani-
ger (16.87%).
The dominant species of mosquito’s larvae in Prajurit
Kulon is Aedes aegypti as illustrated in Figure 4, it has
Importance Value Index (IVI) of 76.88% followed by
73.66% for Culex quinquefasciatus and Aedes albopictus
amounted to 49.46%.
Based on the capturing mosquitoes using ovitrap in
Mojokerto (the rural area) were found that three mosqui-
toes species namely, Aedes aegypti, Aedes albopictus,
and Culex quinquefasciatus. Figure 5 illustrates the
dominant species is the Culex quinquefasciatus with
Importance Value Index (IVI) of 89.58%, followed by
Aedes aegypti (64.58%) and Aedes albo pic t us (4 5.83%).
4. DISCUSSION
Data of Health Department of Mojokerto District
(2012) showed that outbreak of DHF were still suffering
highly in this region. The occurrence of DHF outbreaks
is linked to a number of factors, including the density of
mosquito vectors particularly that of Aedes aegypti. The
precise population density of Aedes aegypti is needed to
sustain dengue virus transmission epidemically or en-
demically has yet to be determined, but experience in
Nganjuk during the past 3 years from 2008 to 2010 sug-
gest that house indices as low as 30% are sufficient for
Figure 2. Important value index (%) of mosquitoes larvae in
Prajurit Kulon.
Figure 3. Important value index (%) of mosquitoes larvae in
Dlanggu.
Figure 4. Important value index (%) of mosquitoes larvae in
Prajurit Kulon (captured with ovitrap).
Figure 5. Important value index (%) of mosquito’s larvae in
Dlanggu (captured with ovitrap).
the epidemic transmission of dengue in area where there
is a low level of immunity in the human population. In
many instances, a small number of actively bitin g female
mosquitoes has infected an entire household. Denser
human population increases virus transmission. Urbani-
zation in tropical countries has resulted in both a prolif-
eration of Aedes aegypti and an increase in the number of
susceptible human host [13]. In the urban area (for ex-

Z. P. Gama et al. / Open Journal of Animal Sciences 3 (2013) 11-16 15
Table 3. Pearson correlation between elevation of each loca-
tion and the density of Aedes aegypti in Mojokerto district.
Elevation Aedes aegypti
Elevation Pearson correlation1 0.418*
Sig. (2-tailed) 0.022
N 30 30
Aedes aegypti Pearson correlation0.418* 1
Sig. (2-tailed) 0.022
N 30 30
*Correlation is si gnificant at the 0.05 level (2-tailed).
ample: Prajurit Kulon), the movement of viraemic per-
sons is a more important means of transporting dengue
viruses than the movement of Aedes aegypti mosquitoes.
Place where people congregate during the day has im-
portant sites of dengue virus transmission. Dengue virus
may also spread in settings related to large numbers of
people such as in hospitals where visitors, patients, and
staffs maybe bitten by infected Ae des aegypti.
Some of other factors that also influence DHF out-
breaks are the beh avior of female mosquitoes to lay their
eggs. Various factors that caused a lot of Aedes and
Culex larvae are found in the surrounding Dlanggu (the
rural area in Mojokerto district) including residential
areas, shrubs (vegetation) lush, plantation, cattle sheds,
gutters, and along the river. Based on the survey in this
rural showed that Culex quinquefasciatus is being the
dominant species. This is in contrast with previous re-
search; it stated that Culex quinquefasciatus is a species
commonly found in urban residential areas.
Aedes aegypti is the predominant species in urban ar-
eas due to the location of housing coincide thus increas-
ing mosquito breeding. Density of eggs/larvae of mos-
quitoes in the container is influenced by the type, color
and ability to absorb water containers. Smooth-walled
containers light and does not absorb water, as it is owned
by ovitrap glass, relatively less favored by mosquitoes.
Smooth surface will make it difficult for laying ovum of
mosquito.
Culex quinquefasciatus is the dominant species due to
the condition of the house adjacent to the yard there are
trees and grass. Around the site there are also stagnant
and dirty water sewers, which are potential sites for
Culex mosquitoes breeding. In addition, there are also
some standing water mosquitoes, eith er rainwater or wa-
ter reservoirs households that are not covered. Mosquito
larvae are generally found in various places such as
aquatic ponds, artificial containers, and trees ho les in the
other pool. Development of mosquito larvae is influ-
enced by abiotic factors, especially temperature. Optimal
temperature in media ranges from breeding places is
25˚C - 27˚C. Based on temperature data obtained from
BMKG [14] showed that the average temperature in the
area of Mojokerto District reach 27˚C on January, so it
can be said that immature mosquitoes experiencing nor-
mal growth process [4].
4.1. The Distribution Pattern of Mosquitoes
in Mojokerto District 2012
Based on calculations using the Morisita index, it was
noted that the distribution pattern of mosquitoes in the
Mojokerto district is uniform. Mosquitoes have a uni-
form distribution due to environmental factors such as
temperature and humidity at that location is not much
different among each site. There are a variety of physical
environments that may affect the distribution of mosqui-
toes, such as home layout, type of container, altitude/
elevation and climate. Presence or absence of mosquitoes
in residential greatly influenced by the infrastructure of
the house itself. The home constru ction, home wall color
and arrangement of goods inside the home are also
deeply affected to determine the home being liked or not
by mosquitoes. Types of containers, including the loca-
tion of containers, container material, container shape,
containers color, the volume of water, cover the container,
and the origin of water in the container are also influ-
enced in the selection of female mosquitoes for laying
their eggs.
One of the models to determine the distribution pattern
of mosquitoes existing in a location is morisita index. It
is useful to know the potential areas that are estimated to
have high mosquito populations. Regions with high mos-
quito populations have the potential to contract the dis-
ease. Spread of mosquito species in Indonesia came from
cities to cities, including the villages, due to transporta-
tion venues carrying rainwater as drums, cans, old tires,
and other items containing larvae mosquitoes. The spread
of the mosquito population is also closely related to the
development of human settlements due to the establish-
ment of the new homes are equipped with a means of
procurin g wat er for daily use.
4.2. Relationship between Elevation and the
Abundance of Aedes aegypti in
Mojokerto District 2012
In general, there were few species per site with in-
creasing altitude. The areas at lowest elevation produced
the greatest number of species but they did not produce a
corresponding greater number of specimens. A decreas-
ing number of mosquito species at the higher elevation
has already been reported [15]. Another studies argued
that the larger number of mosquito species collected at
lower elevation might be due to increased human disrup-
tion in those areas. There is a similarity be tween the pre-

Z. P. Gama et al. / Open Journal of Animal Sciences 3 (2013) 11-16
16
[2] Herrera-Martinez, A.D. and Alfonso, J.R. (2010) Poten-
tial influence of climate variability on dengue incidence
registered in a western pediatric hospital of Venezuela.
Tropical Biomedicine, 27, 280-286.
sent findings and those already made in respect of spe-
cies number, which remained relatively constant for the
first 800 m from the lowest level, followed by a decrease.
There are a number of views about the increased diver-
sity at lower altitudes but the possible explanation could
be the availability of favorable breeding places and pre-
ferred host. Another cause may be related to dispersal of
mosquito, since they have to stop while flying to refuel
with blood/nectar. Further, the tropical zone ranging be-
tween 300 and 900 m has the maximum temperature
27.2˚C - 29.4˚C during June while the lowest (11.1˚C -
13.3˚C) in the month of January. As the optimal range of
temperature for the best survival of mosquito is from
22˚C to 31˚C, hence in the present study the diversity is
more between 500 and 900 m. A slight variation in the
distribution and abundance of most of the mosquito spe-
cies during the study period could be the result of several
interacting climatic factors, which depend on the severity
of the amount an d duration of rain in the rain seaso n. As
these conditions fluctuate season-to-season and place-to-
place, henceforth, restriction in elevation distribution is a
result of habitat specificity. Another possible explanation
is that the elevation may limit niche availability, which
results in differential distribution pattern [15].
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5. CONCLUSION
Mosquitoes found in Mojokerto region consist of five
species, namely Aedes aegypti, Aedes albopictus, Aedes
laniger, Culex bitaeniorchynchus and Culex quinquefas-
ciatus. Although Aedes aegypti is the predominant spe-
cies found in Mojokerto region, 2012, this species still
plays an important role for the outbreak of DHF. Aedes
aegypti has an Importance Value Index (IVI) of 70.48%.
The Morisita index shows that the pattern of spread of
mosquitoes in the Mojokerto district is uniform. The
elevation of area and density of mosquitoes has a posi-
tive association.
[9] BPS (2010) East Java Province in figure. Central Statis-
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6. ACKNOWLEDGEMENTS
The authors are grateful for the financial support of the Directorate
General of Higher Education (DGHE) scholarship batch 5th 2011 from
Indonesia government and grant from the Global Environment Leaders
(GELs) program, Graduate School for International Development and
Cooperation (IDEC), Hiroshima University, Japan.
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[14] BMKG Malang City (2013) Climate data of Mojokerto
region on January. BMKG Malang City, Malang. (in Ba-
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