Bioactivities of selected plant extract against the yellow
fever mosquito Aedesaegypti larvae
ANJUKRISHNA.R
STUDENT
TEACHER (B.Ed. degree)
ST.JOSEPH
COLLEGE OF TEACHER EDUCATION FOR WOMEN KOVILAVATTOM ROAD ERNAKULAM KOCHI
-682035
PHONE
NUMBER: 9497366192
Abstract
The article is based on
the research work to explore the floral biodiversity and enter the field of
using safer insecticides of botanical origin as a simple and sustainable method
of mosquito control. Use of these botanical derivatives in mosquito control
instead of synthetic insecticides could reduce the cost and environmental pollution..The
scope of the study is to Identify bio-insecticides that are efficient, as well
as being suitable and adaptive to ecological conditions, is imperative for
continued effective vector control management. Plants have widespread
insecticidal properties and will obviously work as a new weapon and in future
may act as suitable alternative product to fight against mosquito borne
diseases. The present study assessed
the role of larvicidal activities of Myristica fragrans (Jathikka)
,Indigo feratinctoria (NilamariAmri) and
Adhatoda vasica Nees ( Adalotakam), on Aedes aegypti mosquito larvae.The results is concluded that
Indigo feratinctoria have highest mortality rate than that of Myristica fragrans
and Adhatoda vasica .
Key
words:
Aedes aegypti, plant
extracts of Jathikka, NilamariAmri, Adalotakam ,larvicide
INTRODUCTION
Mosquitoes transmit
serious human diseases, causing millions of deaths every year and the
development of resistance to chemical insecticides resulting in rebounding
vectorial capacity. Plants may be alternative sources of mosquito control
agents. The need and significance of present study is to eradicate the
continuous application of synthetic insecticides that causes development of
resistance in vector species, biological magnification of toxic substances
through the food chain and adverse effects on environmental quality and
non-target organisms including human health. Application of active toxic agents
from plant extracts as an alternative mosquito control strategy was available
from ancient times. These are non-toxic, easily available at affordable prices,
biodegradable and show broad-spectrum target-specific activities against
different species of vector mosquitoes.(Roark RC. 1947) described approximately
1,200 plant species having potential insecticidal value, while (Sukumar et
al 1991) listed and discussed 344 plant
species that only exhibited
mosquitocidal activity. Shallan et al., in 2005 reviewed the current
state of knowledge on larvicidal plant species, extraction processes, growth
and reproduction inhibiting phytochemicals, synergistic, additive and
antagonistic joint action effects of mixtures, residual capacity, effects on
non-target organisms, resistance and screening methodologies, and discussed
some promising advances made in phytochemical research.
METHODOLGY:
The method adopted for
the study is experimentation method it includes the statistical analysis of percentage of
mortality of mosquito larvae on varying concentration (1ml, 2ml, and 5ml) of
plant extract.
Procedure
The larvae of mosquito
were reared for the experiment and are transferred into a beaker containing
distilled water with the help of a fish net. The larvicidal assay larvae of
mosquito larvae were exposed to test concentrations of 1ml, 2ml and 5ml leafs
extract of of Myristica fragrans ,Indigo feratinctoria , Adhatoda vasica Nees in 10 ml of water. All the petridishes were
labeled which indicated the source plant and the concentration of leaf extract
used. Each was filled with 10 ml of distilled water using the measuring
cylinder. The different concentrations of plant extract used were 1ml, 2ml and
5ml. 10 larvae were transferred to each petridish. The observations were made
after 1hr, 2hrs, 20hrs, 24hrs and 48hrs.
ANALYSIS
AND INTERPREATATION:
In preliminary
comparative studies, Myristica fragrans (Jathikka) ,Indigo feratinctoria
(NilamariAmri) and Adhatoda vasicaNees (
Adalotakam), were tested against Ae. aegypti larvae. Among these
Indigo feratinctoria showed similar levels of susceptibility to 1ml 2ml and 5ml
extracts. The fresh extract of leaves showed much higher activity than the other
parts, against Ae.aegypti.
·
The effect of 1ml extract of Myristica fragrans
was shown after 2hrs where the mortality was only 20%. It was doubled after 20 hrs and remained as
such after 24hrs. But after 48 hrs all larvae died .In the case of 2ml extract
60% mortality after 20hrs. 80% of the
larvae died after one day and all the remaining died after two days. 100% of
the larval death was observed after 20 hrs when 5ml of the extract was used.
·
Effect of Indigo feratinctoria extract on
mosquito larvae was very rapid leading to death of mosquito larvae in the case
of 1ml, 2ml and 5ml extract. 100%
mortality was observed after 1hr in all the varying concentrations of the
extract used.
·
But in case of Adhatoda vasica extract on
mosquito larvae, 50% mortality was observed after 20hrs with 1ml extract. It was increased to 70% after 48hrs. 2ml
extract showed the effect after 1hr where 20% larvae died. Mortality was 70% and 100% after 24 and 48hrs
respectively. But when 5ml of the extract was used all the larvae death within
20hrs. All the selected plants showed larvicidal activity.
·
Major effect was observed in the case of
Indigo feratinctoria where 100% mortality was observed after 1hr in all the
varying concentrations of the extract used.
·
Above all the results it is concluded
that Indigo feratinctoria have highest mortality rate than that of
Myristica fragrans and Adhatodavasica .
CONCLUSION:
Plants are considered
as a rich source of bioactive chemicals and they may be an alternative source
of mosquito control agents. To prevent proliferation of mosquito borne diseases
and to improve quality of environment and public health, mosquito control is
essential. The major tool in mosquito control operation is the application of
synthetic insecticides such as organochlorine and organophosphate compounds.
But this has not been very successful due to human, technical, operational,
ecological, and economic factors. In recent years, use of many of the former
synthetic insecticides in mosquito control programme has been limited. The
activity of crude plant extract is often attributed to the complex mixture of active
compounds. Plants have widespread insecticidal properties and will obviously work
as a new weapon and in future may act as suitable alternative product to fight
against mosquito borne diseases. The results reported here open the possibility
of further investigation of efficacy on their larvicidal properties of natural
product extracts.
REFERENCES
Bowers WS, Sener B,
Evans PH, Bingol F, ErdoganI(1995). Activity of Turkish medicinal plants
against mosquitoes Aedesaegypti and Anopheles gambiae. Insect SciAppl; 16 :
339-42.
Brown AW(1986).
Insecticide resistance in mosquitoes: a pragmatic review. J Am Mosq Control
Assoc; 2 : 123-40.
Cheng SS, Chang HT,
Chang ST, Tsai KH, Chen WJ (2003).Bioactivity of selected plant essential oils
against the yellow fever mosquito Aedesaegypti larvae.BioresTechnol; 89(1):
99–102.
Roark RC(1947) . Some
promising insecticidal plants. Econ Bot; 1 : 437-45.
Rose RI(2001).
Pesticides and public health: integrated methods of mosquito management. Emerg
Infect Dis; 7 : 17-23.
Shaalan EAS, Canyonb D,
Younesc MWF, Abdel-Wahaba H, Mansoura AH(2005). A review of botanical
phytochemicals with mosquitocidal potential. Environ Int; 3 : 1149-66.
Sukumar K, Perich MJ,
BoobarLR(1991). Botanical derivatives in mosquito control: a review. J Am Mosq
Control Assoc; 7 : 210-37.
Senthilnathan S, Choi
MY, Seo HY, Paik CH, Kalaivani K, Kim JD(2008). Effect of azadirachtin on
acetylcholinesterase (AChE) activity and histology of the brown
planthopperNilaparvatalugens (Stål).Ecotox Environ Safety; 70 : 244-50.
