Journal of Mosquito Research 2015, Vol.5, No.19, 1-7
5
Table 4 Log probit and regression analyses of larvicidal activity of etanol leaf extract of
A. reticulata
against different larval instars of
Cx. quinquefasciatus
Larval instar
Exposure period (h)
LC
50
(ppm)
LC
90
(ppm)
Regression equation
R
2
value
1
st
24
0.5021
2.0977
Y = 89.3157 +.7428 X
0.6111
48
0.5300
1.9153
Y = 90.7165 +.6520 X
0.6111
72
-
-
-
-
2
nd
24
2.9374
7.43
Y = 32.8936 + 4.4983X
0.7628
48
1.2057
4.0729
Y = 71.6242 + 1.9392X
0.6286
72
0.6295
2.2741
Y = 87.6987 +.8602 X
0.5878
3
rd
24
4.2048
9.2481
Y = 13.379 +5.6732 X
0.8542
48
1.728
4.1812
Y = 61.6924 + 2.671X
0.5618
72
1.0528
2.887
Y = 79.8209 +1.4211 X
0.5383
4
th
24
6.2245
15.8776
Y = - 0.3996 +5.8925 X
0.9800
48
3.6999
10.488
Y = 22.9820 +4.8988 X
0.8850
72
2.3474
5.5919
Y = 46.0531 + 3.6969X
0.6488
Note: LC = Lethal Concentration, X= Concentration, Y= mortality, R2
= Coefficient of determination. First
instar larvae showed 100% mortality at 72 h of exposure with all tested concentrations, hence, no LC
50,
LC
90
, values, Regression
equation and R
2
value were obtained
Table 5 Completely randomized three ways ANOVA using instars (I) of
Ae. aegypti
, hours (H), and Concentrations (C) of ethanol
leaf extract of
A. reticulata
as three independent parameter
Source of variation
Sum of squares(SS)
Degree of freedom (df)
Mean of squares (MS) F value
p-level
Instars(I)
705.81
3
235.27
259.28
0
Time(H)
120.04
2
60.02
66.14
0
Conc.(C)
1399.98
5
279.99
308.57
0
I×H
34.85
6
5.81
6.40
0
I×C
141.69
15
9.45
10.41
0
H×C
18.69
10
1.87
2.06
0.03
I×H×C
39.98
30
1.33
1.47
0.07
Within groups
130.67
144
0.91
-
-
Total
2591.70
215
12.05
-
-
4.2 Preparation of solvent extract
Leaves of
A. reticulata
were dried in shade for 10-12
days and then chopped finely. Two hundred grams of
finely chopped leaves were packed in a Soxhlet
apparatus and the plant extract was prepared using
2000 ml of ethanol. The period of extraction was 72 h.
The pooled extract was evaporated by rotary evaporator
to obtain semisolid extract. Semi solid extract was
stored in refrigerator at 4 ͦ
C for further use.The semi
solid extract (0.05 g) were dissolved in 100 ml of 5 %
ethanol to prepare stock test solution. After preliminary
trial, required graded concentration i.e. 1.5, 3, 6, 12,
18 and 24 ppm were prepared adding required volume
of stock test solution with required volume of distilled
water, making 100 ml of final test solution of different
concentrations which were used in bioassay experiments.
Stock test solution was prepared freshly on the same
day of bioassay experiments.
4.3 Test mosquitoes
The present study was conducted at Mosquito,
Microbiology and Nanotechnology Research Units,
Parasitology Laboratory, Department of Zoology, The
University of Burdwan, Burdwan (23
◦
16
ꞌ
N, 87
◦
54
ꞌ
E)
West Bengal, India. Larvae of
Ae
.
aegypti
and
Cx.
quinquefasciatus
mosquitoes were taken for bioassay
