Imparting Mosquito Repellent Agents & Assessing Mosquito Repellency on Textile
es (WHO 1996). This test does not in-
volve human participants as the bait
to lure the mosquitoes come to fabric
and this in one of advantages of this
method. Due to this factor, this meth-
od is less chosen by the researcher to
conduct the mosquito repellency test
on clothing. The use of artificial blood
or animal blood as bait in order to at-
tract host seeking mosquitoes, which
in this cone test could help future stud-
ies to better assess of the eficacy on
the treated clothing. In the cone test,
the mosquitoes might spend more time
resting on the cone than on the treat-
ed surface during the 3 min exposition.
The 3-min exposure test was carried
out under the temperature of 27°C. The
standard WHO plastic cone was placed
on top of the treated surface of the
sample and secured using a masking
tape. Five to ten female mosquitoes
were blown into the cone using aspira-
tor and mosquitoes were exposed to
the treated surface.
The low density mosquito number used
for this method made it easy observa-
tion for the mosquito behaviour. The
numbers of mosquitoes resting on the
treated samples were counted within
3-min exposure.
At the end of the exposition, the mos-
quitoes were transferred to the plastic
cones for further observation. The plas-
tic cup kept in an insecticide-free air
and supplied with 10 % sucrose solu-tion. The number of immobilized,
knocked down test mosquitoes was
determined 1 h after the exposition and
the mortality rate was determined af-
ter 24 h. The percent mosquito repel-
lency was calculated using the follow-
ing formula:
% Mosquito mortality =
(MR - MC)/(100 - C) × 100
where MR represents the mosquitoes
mortality in test replicate while the MC
corre- sponds to the mosquitoes mor-
tality in control samples. The natural
mortality rate is determined with an
untreated fabric as reported by (Lalit
Jajpura 2015). The results will be col-
lected and performed in ANOVA soft-
ware for further analysis. Only one
study by Farag et al. (2011) demonstrat-
ed cone test for their mosquito repel-
lency test.
Excito chamber test
The excito chamber method is a mod-
ified custom method to observe the
mosquito behaviour change in the form
(Fig. 3) of moving away from the treat-
ed to untreated fabric. This method and
Cone test method does not involve the
human subject to lure the mosquito.
However, both methods can determine
the behaviour of the mosquitoes to-
wards the treated materials. The box
is made with one front and exit panel
occupied with single escape portal. It
builds up with screened inner cham-
NCM-OCTOBER 2021
42ber, glass holding frame and door cov-
er. The mosquito was starved overnight
or least minimum 4 h before the test.
The behaviour of mosquito was ob-
served in term of number of escaped
mosquitoes to another space and re-
main mosquitoes inside the chamber
which filled with treated product. The
observation is recorded after 10 and
30 min exposure. The test was con-
ducted in daylight and repeated for four
times. The percentage of mosquito re-
pellency was calculated using the for-
mula:
% Mosquito repellency =
(NES + NDE)/(NEX) × 100
where NES corresponds to the num-
ber of mosquitoes escaped, while the
NDE refer to the number of mosqui-
toes dead and last is NEX represents
the number of mosquitoes exposed.
The results will be collected and per-
formed in ANOVA software for further
analysis. Three studies (Alipour et al.
2015; Anitha et al. 2011; Chareonvir-
iyaphap et al. 2002; Maheshwari and
Ramya 2014; Roberts et al. 1997;
Sumithra and Vasugi Raja 2012) con-
ducted this method of mosquito repel-
lency in their studies.
In general comparison, the suitability
of the three methods reviewed accord-
ing to dif- ferent intended test objec-
tives or situation. For example cone
test is more suitable for a study that is