Synergistic
efficacy of Solanum xanthocarpum and Withania somnifera on
larvae of mosquito vector speciesÂ
Â
S.K. Bansal,
Karam V. Singh* and Himani Sharma
Desert Medicine
Research Centre (ICMR), New Pali Road, Jodhpur-342 005, India
*Corresponding
Author’s E-mail: karamvir@dmrcjodhpur.org
Â
|
Â
Â
Â
Publication
Data
Paper received:
13 September 2013
Â
Revised received:
06 February 2014
Â
Accepted:
08 October 2014
|
Â
Abstract
Synergistic
larvicidal efficacy of methanol extracts from yellow ripe fruits of Solanum
xanthocarpum (Schrad and Wendl.) and red fruits of Withania somnifera
(Dunal) (Fam. Solanaceae) was evaluated against late 3rd or early
4th stage larvae of Anopheles stephensi (Liston), Aedes
aegypti (Linnaeus) and Culex quinquefasciatus (Say), using
standard WHO technique. Experiments were carried out with methanol extracts
of fruits of S. xanthocarpum (SX) (24hr LC50: 77.7, 121.6,
142.8) and W. somnifera (WS) (108.4, 135.1, 1092.1 mg l-1)
which revealed that extracts from S. xanthocarpum were more effective as
compared to W. somnifera with all the three mosquito species,
respectively. For synergistic studies on An. stephensi six different binary
pairs viz. WS:SX (1:1), WS:SX (1:2) and WS:SX (1:3); SX:WS (1:1),
SX:WS (1:2) and SX:WS (1:3) were prepared and a dose response curve was
established to determine the 24 and 48 hr LC50 and LC90
values, along with their 95% confidence limits, regression equation,
chi-square (χ2)/ heterogeneity of response by log probit
regression analysis. The 24 and 48hr LC50 values as determined for
three binary pairs viz. WS:SX (1:1), WS:SX (1:2) and WS:SX (1:3) were 32.7,
30.6 and 22.2 and 22.9, 16.3 and 12.9 mg l-1 while the values for
other three pairs viz. SX:WS (1:1), SX:WS (1:2) and SX:WS (1:3) were 32.7,
47.5 and 63.8 and 22.9, 29.1 and 50.2 mg l-1 respectively. From
the results it is clear that An. stephensi was very much susceptible to the
binary pair WS:SX (1:3) as compared to the binary pair SX:WS (1:3) or in
other words, the efficacy went up with increase in proportion of S.
xanthocarpum and went down with increase in proportion of W. somnifera
extract. Experiments were done by mixing different fractions viz.
1/2, 1/3, 1/4th of LC50 each of SX and WS and it was
observed that synergistic effect was observed even up to 1/4th of
LC50 of these two plant extracts. Synergistic Factor (SF) and
Co-toxicity Coefficient (CTC) were also determined to show the antagonistic
and synergistic effects. The study would be of great importance while
formulating vector control strategy based on utilization of the most effective
synergist pair. Â Â Â
Â
Â
 Key
words
Arid
region, Desert plants, Larvicidal, Mosquitoes, Syngistic
Â
Â
Â
|
Copyright
© 2015 Triveni Enterprises. All rights reserved. No part of the Journal can
be reproduced in any form without prior permission. Responsibility
regarding the authenticity of the data, and the acceptability of the
conclusions enforced or derived, rest completely with the author(s).
|