Mosquitoes
are major vectors that transmit disease like Malaria, Dengue fever, Leishmaniasis,
Filariasis and other diseases. Disease caused by mosquitoes have been of economic importance. This
research evaluate the efficacy of Hyptis
suaveolens leaf extract on adult
mosquito population, the plant were collected from it natural environment
within Dutse metropolis at warwade dam Dutse Jigawa state.The plant leaves were
air dried and extract was obtained using sohxelet extractor, four group of 20
mosquitoes each were sprayed with the dissolved extract at concentractions of
100mg/ml, 300mg/ml and 500mg/ml. The result shows that high concentration give
the highest mortality, this signify that the greater the concentration, the
greater the effect of the leaf extract on the mosquito population. The
phytochemicals found to be responsible for these activities are Saponins, Phlabotonins,
Tannins and Phenones, The study conclude that Hyptis suaveolens have effect on Mosquito population.
Table of Contents
CHAPTER ONE
INTRODUCTION
1.1 Background
Mosquitoes
play a unique function as vectors for many diseases; these diseases often have
a wide distribution and a high number of cases. Because of its role as a
vector, mosquito-borne diseases kill more people worldwide each year than any
other single factor (Brown,1986). 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. It is due to lack of novel insecticides, high cost of synthetic
insecticides, concern for environmental sustainability, harmful effect on human
health, and other non-target populations, their non-biodegradable nature,
higher rate of biological magnification through ecosystem, and increasing
insecticide resistance on a global scale (Brown,1986, and Russell et al.,2009).Thus, the Environmental
Protection Act in 1969 has framed a number of rules and regulations to check
the application of chemical control agents in nature. It has prompted
researchers to look for alternative approaches ranging from provision of or
promoting the adoption of effective and transparent mosquito management
strategies that focus on public education, monitoring and surveillance source
reduction and environment friendly least-toxic larval control. These factors have
resulted in an urge to look for environment friendly, cost-effective,
biodegradable and target specific insecticides against mosquito species.
Considering these, the application of eco-friendly alternatives such as
biological control of vectors has become the central focus of the control
programme in lieu of the chemical insecticides.
One
of the most effective alternative approaches under the biological control
programme is 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. Further, unlike conventional insecticides which are based on
a single active ingredient, plant derived insecticides comprise botanical
blends of chemical compounds which act concertedly on both behavioural and
physiological processes. Thus there is very little chance of pests developing
resistance to such substances. Identifying bio-insecticides that are efficient,
as well as being suitable and adaptive to ecological conditions, is imperative
for continued effective vector control management. Botanicals have widespread
insecticidal properties and will obviously work as a new weapon in the arsenal
of synthetic insecticides and in future may act as suitable alternative product
to fight against mosquito borne diseases.
Roark
(Roark, 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.,2005) reviewed the current state of knowledge on larvicidal
plant species, extraction processes, growth and reproduction inhibiting
phytochemicals, botanical ovicides, 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.
The
mosquitocidal activities of various herbal products from edible crops,
ornamental plants, trees, shrubs, herbs, grasses and marine plants according to
the exaction procedure developed in eleven different solvent systems and the
nature of mosquitocidal activities against different life stages of different
vector species as a ready reference for further studies.
The
use of plant extracts to control parasitic infections has been a strong
interest of researchers around the globe, carrying the potential for
development of alternative control strategies. In selecting plants to test as
agents against mosquitoes, it may be useful to include endogenous knowledge
about plant resources. Including plants which have been used as traditional
medicines allows researchers to incorporate the observations of a wider variety
of experiences. While plant selection should draw from a broader inventory,
standard testing regimens for potential insecticides should be utilized by
researchers in order to produce results that facilitate comparative analyses
(CTD/WHO PES/IC, 1996; WHO CDS/ WHO PES, 2005). It is important that these
efforts include careful analysis of the solvents used in the extraction or
re-suspension process to ensure that adequate controls exist for comparison
between the active compounds and the solvent (Zahir et al., 2009). Utilizing endogenous knowledge concerning plants
with traditional medicinal value has proven fruitful in identifying potential
sources of phyto-extracts with insecticidal activity (Rahuman, et al., 2009), There have been many
attempts to assay the activity of particular plant extracts against vectors of
human disease, in particular through the utilization of plants for which such
knowledge exists (Mathew, et al.,
2009). Recent studies using these approaches have yielded some promising plants
with larvicidal activity. Essential oils that have indicated adult repellence
have also been shown to function as larvicides, indicating a cross-functional
potential for utilizing these natural products (Zhu, et al., 2008). Therefore this project will provide more information
to scientific and local community on the effect of Hyptis suaveolens on mosquito .The plant is reported to possess
repellent activity against insect pests of stored grains and also use as
treatment of many disease.
1.2. Statement of Research Problem
Mosquitoes
serve as vector of tropical and subtropical parasites that cause diseases like
Dengue fever, Dengue haemorrhagic fever, Malaria, Japanese encepahalitis and
Filariasis that afflict millions of people worldwide (Service, 1983; Gubler,
1998; WHO 1992). There have been various researches on the use of plant exract
against mosquito but on the use of Hyptis
suaveolens
against adult mosquitoes there is no/little documented research work.
1.3 Justification
Mosquitoes are the oldest human
enemy and represent a significant threat to human health because of their
ability to vector pathogens that cause diseases like Dengue fever, Dengue
haemorrhagic fever, Malaria, Japanese encepahalitis and Filariasis that afflict
millions of people worldwide (Service, 1983; Gubler, 1998; WHO 1992). The
continuous use of synthetic insecticides, its toxicity problem together with
the growing incidence of insect resistance has called the need for novel
insecticide. Plant extracts may be alternative sources that constitute a rich
source of bioactive compounds that are biodegradable and environmentally
friendly.
Login To Comment