Journal of Mosquito Research 2015, Vol.5, No.19, 1-7
3
Table 1 Percent mortality of different larval instars of
Ae. aegypti
exposed to different concentrations of ethanol leaf extract of
A.
reticulata
(Mean mortality percent±standard error)
Instar
Conc. ( ppm )
% Mortality (+SE) at different exposure period
24h
48h
72h
1
st
1.5
13.33±3.33
26.66±6.66
33.33±3.33
3.0
20.00±00.0
53.33±8.88
63.33±8.88
6.0
33.33±3.33
66.66±12.0
76.66±8.88
12.0
43.33±3.33
83.33±8.88
93.33±3.33
18.0
100.0±00.0
100.0±00.0
100.0±00.0
24.0
100.0±00.0
100.0±00.0
100.0±00.0
2
nd
1.5
10.00±00.0
20.00±5.88
30.00±5.88
3.0
30.00±5.88
40.00±5.88
53.33±8.88
6.0
53.33±8.88
63.33±8.88
73.33±.88
12.0
60.00±11.5
70.00±10.0
76.66±6.66
18.0
80.00±00.0
86.66±3.33
96.66±3.33
24.0
100.0±00.0
100.0±0.00
100.0±00.0
3
rd
1.5
10.00±00.0
13.33±3.33
23.33±3.33
3.0
13.33±3.33
40.00±5.88
50.00±5.88
6.0
26.66±3.33
50.00±5.88
60.00±5.88
12.0
40.00±5.88
60.00±5.88
66.66±3.33
18.0
56.66±3.33
66.66±3.33
76.66±3.33
24.0
66.66±3.33
83.33±3.33
93.33±3.33
4
th
1.5
00.0±00.0
00.0±00.0
00.0±00.0
3.0
00.0±00.0
00.0±00.0
00.0±00.0
6.0
00.0±00.0
00.0±00.0
00.0±00.0
12.0
00.0±00.0
00.0±00.0
00.0±00.0
18.0
50.00±5.78
53.33±8.88
60.0±5.88
24.0
66.66±12.00
70.0±11.50
80.0±11.5
Note: Control No mortality (For all instars)
149.97, 193.43 and 230.71 ppm and against
Ae.
aegypti
the LC
50
values were 177.40,144.00,199.72
and 257.17 ppm after 24 h of exposure respectively. In
comparison much lower LC
50
values of ethanol
extract of leaves of
A. reticulata
against 1
st
–4
th
instar
larvae of
Cx. quinquefasciatus
viz.
, 0.5021, 2.9374,
4.2048 and 6.2245 ppm and 6.8839, 5.9929, 14.5745
and 19.8836 ppm against
Ae. aegypti
after 24 h of
exposure were recorded. Bhattacharya
et al., (2014)
reported the larvicidal activity of the chloroform and
methanol extract (1:1
v/v
) of the leaves of
Ravenala
madagaskariens is
against
Cx. quinquefasciatus
having LC
50
and LC
90
values 25.41 and 90.98 ppm
respectively after 72 h of exposure for 1
st
instar larvae.
However, in this study, ethanol leaf extract of
A.
reticulata
recorded LC
50
and LC
90
values of 0.5021
and 2.0977 ppm against1
st
instar larvae of
Cx.
quinquefasciatus.
The results indicate that ethanol leaf
extract of
A. reticulata
can be used effectively against
Ae. aegypti
and
Cx. quinquefasciatus
mosquito species.
Because of non-toxic effect on tested non-target
organisms, its use will also be safer. Further study is
needed to identify the chemical structure of actual
compound (s) involved in larvicidal activity.
4 Materials and methods
4.1 Collection of plant materials
After proper identification of the plant, fresh mature
leaves of
A. reticulata
(aged about one to four years)
were
collected from Burdwan town, West Bengal,
India (23
◦
16
ꞌ
N, 87
◦
54
ꞌ
E) during the month of September
and October, 2013,
and the voucher specimen (voucher
No.
GCZSM-4) was deposited as herbarium to
Mosquito, Microbiology and Nanotechnology Research
Units, Parasitology Laboratory, Department of Zoology,
The University of Burdwan, West Bengal, India. After
collection, the leaves were washed gently with water
and dried on paper towels.
