Journal of Mosquito Research 2015, Vol.5, No.19, 1-7
6
Table 6 Completely randomized three ways ANOVA using instars (I) of
Cx. quinquefasciatus
, hours (H), and Concentrations (C) of
ethanol leaf extract of
A. reticulata
as three independent parameters
Source of variation
Sum of squares(SS)
Degree of freedom(df)
Mean of squares(MS)
F value
p-level
Instars(I)
285.69
3
95.23
300.73
0
Time(H)
158.14
2
79.07
249.70
0
Conc.(C)
625.36
4
156.34
493.70
0
I×H
39.68
6
6.61
20.88
0
I×C
193.31
12
16.11
50.87
0
H×C
96.08
8
12.01
37.93
0
I×H×C
57.66
24
2.40
7.59
0
Within groups
38
120
0.32
-
-
Total
1493.91
179
8.35
-
-
experiments from laboratory mosquito colonies which
were maintained in the laboratory. Mosquito colonies
were kept free from insecticides, repellents and
exposure to pathogens. The mosquito larvae were fed
with artificial food i.e. mixture of dog biscuits and
dried yeast powder in the ratio of 3:1.
4.4 Larvicidal bioassay
The bioassay experiments were done according to
standard WHO procedure (1981) with slight modification.
All instars larvae of
Ae
.
aegypti
and
Cx. qui-
nquefasciatus
were used during bio assay experiments.
Thirty larvae were put in different plastic bowls of
225 ml capacity and 9 cm in diameter containing each
with 100 ml of test solution of different concentrations.
After preliminary trial, 1.5, 3, 6, 12, 18 and 24 ppm
and 1.5, 3, 6, 12 and 18 ppm dosages were used
against
Ae. aegypti
and
Cx.
quinquefasciatus
respectively for larvicidal bioassay experiments.
Ethanol treated controls were run concurrently by
mixing 100 ml of tap water with 0.5 ml of ethanol.
Larval mortalities were recorded after 24, 48, and 72 h
of exposure cumulatively. Dead larvae were detected
when they fail to move after touching with fine brush
on cervical or siphon region. All bioassays and control
experiments were replicated three times on three
separate days under laboratory conditions at 25-30
º
C
and 80-90% relative humidity.
4.5 Effect on non target organisms
Ethanol leaf extract of
A. reticulata
were tested against
non target organisms
viz
.,
Chironomus circumdatus
larvae,
Diplonychus annulatum
and tadpoles of frog with LC
50
value of the extract against 3
rd
instar larva of
Cx.
quinquefasciatus
at 24 h of post exposure. Each tested
non target organism was kept in an environment
similar to their natural habitat for acclimation in the
laboratory as per procedure used by Suwannee et al.,
(2006). Ten early 4
th
instar
Chironomus circumdatus
larvae, 10 3
rd
instar nymph of
Diplonychus annulatum
and 10 tadpoles of frog were kept separately in 500 ml
glass beaker containing 200 ml of pond water and
treated at the dosages mentioned. Number of dead
non-target organisms was noted after 24, 48 and 72 h
of exposures. A set of control (200 ml of pond water
with 0.5 ml of ethanol) of each organism was run
parallel. Each experiment (including control) was
replicated thrice on separate three days.
4.6 Statistical analyses
The computer software STAT PLUS 2009 - trial
version was used to calculate the LC
50,
LC
90
values
through Log Probit analyses (95% confidence level)
,
regression equations, coefficient of determination (R
2
)
and completely randomized three way ANOVA.
5 Acknowledgements
We are thankful to Professor Dr. A Mukhopadhyay,
Department of Botany, The University of Burdwan,
for his kind help to identify the plant species. We are
also grateful to UGC-DRS for providing financial
assistances.
Conflict of interest
We have no conflict of interest.
References
Adhikari U., Singha S., and Chandra G., 2012, In vitro repellent and larvicidal
efficacy of
Swietenia mahagoni
against the larval forms of
Culex
quinquefasciatus
Say, Asian Pac. J. Trop. Biomed., S260-S264
Bhatacharya K., Burman S., Nandi S., Roy P., Chatterjee D., and Chandra G.,
2014, Phytochemical extractions from the leaves of
Ravenala
madagaskariensis
from Sundarban area and its effect on southern
house mosquito (
Culex quinquefasciatus
Say 1823) larvae, J. Mosq.
Res., 4 (12): 1-6
Activity of Turkish medicinal plants against mosquitoes
Aedes aegypti
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Anopheles gambiae
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