1. INTRODUCTION
1.1 RATIONALE
As a tropical country, the Philippines has numerous environmental, economic, and
health-related issues. Mosquitoes have a negative impact on human health and wellbeing for two reasons: the transmission of mosquito-borne diseases and the nuisance
associated with mosquito bites. (Becker et al., 2010).
Mosquitoes serve as vectors for a variety of diseases, including malaria,
chikungunya, yellow fever, filariasis, and dengue. Every year, millions of people are
killed. Dengue fever is the most common mosquito-borne viral disease in the world. It is
endemic in the Philippines and is one of the country's eight most prevalent infectious
diseases. The World Health Organization (WHO) reported a total of 22,277 dengue
cases and 126 deaths from January 1 to April 30,2022, a 15% decrease from the 26,114
cases reported in the same time in 2021. (DOH Philippines, 2022). However, it has been
steadily spreading in the country due to mosquitoes from dirty locations. Higher
temperatures and longer wet seasons both add to the magnitude of this lethal outbreak.
Mosquito-borne diseases are still major public health concerns in most Southeast Asian countries because of their tropical or subtropical climate, the frequently poor
drainage system especially during rainy seasons, and the presence of many fish ponds,
irrigation ditches and rice fields which provide abundant mosquito breeding places
(Narumon et al.,2005). Although chemical vector control programs have been in place
for a long time, these mosquito-vector diseases persist due to homeowners' refusal to
spray with synthetic pesticides, changes in vector biting patterns, and the evolution of
mosquito resistance to conventional insecticides.
Mosquito vector control is facing a threat due to the emergence of resistance to
synthetic insecticides. Extensive use of chemical insecticides for control of vector borne
diseases has created problems related to physiological resistance to vectors, adverse
environmental effects, high operational cost and community acceptance. (Virendra K
Dua et al., 2009)
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In this context the search for new strategies or natural products to control vector
diseases is desirable due to prevalent occurrence of vector resistance to synthetic
insecticides and the problem of toxic nonbiodegradable residues contaminating the
environment and undesirable effects on nontarget organisms (Jantan et al., 2015).
Searching for new control agents from natural products such as plant secondary
metabolites has gained popularity among researchers in countries with a strong herbal
tradition and large numbers of plants have been reported to possess insecticidal activity
(Yang et at., 1991). Numerous plant products have been reported either as insecticides
for killing larvae or adult mosquitoes or as repellents for mosquito biting and are one of
the best alternatives for mosquito control (Virendra K Dua et al., 2009).
The chemicals obtained from plants have exploded as weapon in future mosquito
control program. Different chemical group of phytochemicals such as steroids, alkaloids,
terpenes and phenolic compound were found for insect control. Natural products are
generally preferred in vector control measure due to their less deleterious effect thus
identifying active compounds from natural products against mosquitoes is worthwhile
(Aarthi et al., 2021).
Biological pest management is extremely useful in situations where it is
unfeasible to spend money on highly expensive and environmentally damaging chemical
pesticides. Long-term benefits and economic advantages are provided through
biocontrol.
Antidesma bunius (Linn) Spreng is more popularly known in the Philippines as
“bignay”. The plant is a small, smooth, dioecious tree, 4 to m high. Leaves are shiny,
oblong, 8 to 20 cm long. The fruit is fleshy, ovoid in shape transforming its color from
green to pale yellow then red to blackish color as it ripens. The edible fruit is about 8mm
long with only one seed and grow in clusters like grapes (Banerjee S, 2013). A. bunius is
widespread in the Philippines but is also claimed to be common in the wild (from the
lower Himalayas in India, Ceylon and Southeast Asia and northern Australia), grow in
Indonesia, Thailand and cultivated in Malaysia (Morton J, 1987).
The entire plant is of medicinal value acting as anti-dysenteric, anti-oxidative,
anticancer and anti-diabetic and gives suforific effects. An analysis of 15 cultivars of
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A.bunius grown in northeast Thailand have shown that all cultivars contain three major
flavonoids namely catechin, procyanidin B1 and procyanidin B2. The very presence of
these phytochemicals as plants’ natural defense could be a strong pesticide property in
A.bunius fruit (Belmi et al, 2014).
These obvious issues prompted the researcher to conduct this investigation in
order to discover a plant-derived organic, healthier, and cost-effective insecticide that
may help to minimize, if not eliminate, mosquito vector diseases. The current study
hypothesized that A.bunius fruit extract had insecticidal properties that can be used to
control larval and pupa mosquitoes.
Thus, from a practical aspect, the fight against mosquito vector illnesses affects
everyone. It is no longer just the health office vs. the residents.
However, according to this study, very few, if any, studies on its fruits' pesticide
properties have been conducted thus far, making this initiative a first of its kind. The
study's findings should be noteworthy and contribute to a viable solution to the rising
number of mosquito vector cases.
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Conceptual Framework
Presented in Figure 1 is the research paradigm of the study showing how each
treatment directly affected the mortality rate of Mosquito larvae (Culex quinquefasciatus
and Aedes aegypti). As shown in the diagram, the study assessed the insecticidal effect
of Antidesma bunius fruit extract in different preparations. T1 – (50% concentration of
A.bunius fruit extract), T2 – (75% concentration of A.bunius fruit extract), T3 – (100%
concentration of A.bunius fruit extract). Ten (10) mL of each concentration was used for
each treatment. There was a positive control using commercial insecticide and negative
control using distilled water as bases for comparison of results.
Figure 1: The Conceptual Framework of the study
OBJECTIVES
To reduce the number of mosquito larvae by terminating their possible breeding
sites which are necessary in their system of reproduction.
The study assesses the larvicidal activity of Bignay (Antidesma bunius) against
Mosquito vector (Culex quinquefasciatus and Aedes aegypti).
This investigation plans to answer the accompanying inquiries:
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a.
To determine the larvicidal effect of A. bunius fruit extract on Mosquito Larvae in
the following concentrations
a. 50%
b. 75%
c. 100%
2. To compare the larvicidal activity of Antidesma bunius fruit extract to BTI which is
known to eradicate mosquito larvae.
Hypotheses
The hypotheses that follow were tested in this study using a 0.05 level of
significance.
HO: There is no significant difference on the concentrations of our experimental setup.
Ha: There is a significant difference on the concentrations of our experimental setup.
HO: There is no significant difference between the dependent variable A.bunius fruit
extract and the positive control variable BTI.
Ha: There is a significant difference between the dependent variable A.bunius fruit
extract and the positive control variable BTI.
Scope and Limitations of the Study
The study's goal is to use a Natural Biological method that is safe
environmentally and economically advantageous. Antidesma bunius fruit extract in
varied preparations were used against the Mosquito larvae (Culex quinquefasciatus and
Aedes aegypti). Specifically, the study includes:
Mosquito larvae (Culex quinquefasciatus and Aedes aegypti). Samples were
collected from various parts of the household of the researcher. The assortments were
made by catching and hand-get strategies (Pregoner et al., 2019). The larvae were then
filtered using strainer, and kept in an isolated traps incase of mosquito emergence.
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Thirty (30) I, II, II, IV instar larvae were used in five (5) set-ups with three (3) replicates of
varied concentrations.
Commercial insecticides. To compare the results on the results on the mortality
rate of Mosquito larvae in varied concentrations of A.bunius fruit extract.
Significance of the Study
From the findings of this research, there is a strong possibility that the number of
mosquito vector cases may decrease which can lead to major breakthroughs in the
market of larvicides. The field of medicine, urban communities as well as the goals of the
DOH.
The study's design produces a biological method insecticide that may be
effective and inexpensive for individuals, more so even a lot safer and environmentally
friendly since it is made from all-natural ingredients.
The household Residents, Community, and society. Citizens, especially in urban
communities, wherein mosquito breeding is prone will benefit from this study as they are
the primary population who are most affected and vulnerable to the mosquito diseases.
This study aimed to establish a mosquito vector control practice used at home by
residents in eradicating their breeding sites \and assess awareness and knowledge of
natural pest management.
Furthermore, this study also intersects with the advocacies of the DOH in
controlling and preventing mosquito diseases at households, in communities and
generally nationwide. With the efficiency of the study, it may eventually be proposed to
local government in the country as a new medium and innovation to control mosquito
diseases in their communities.
The study provides a safe, sustainable and reliable mosquito larvicide for all
which is executed in an approach that is not common to other mosquito larvicides sold in
the market as it determines the efficacy of a new plant-based larvicidal.
Department of Health (DOH). The study will significantly contribute to the
department in searching for alternative methods in terminating mosquito vectors and opt
to use biological method which is inexpensive and environmentally safe.
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Students & Future Researchers. The examination will let understudies and future
Analysts Investigate the most encouraging chances to build benefits and decrease the
wellbeing and ecological dangers of pesticide use. Suggest a proper job for the open
area in examine, item improvement, item testing and enlistment, usage of pesticide use
methodologies, and state-funded training about pesticides.
Definition of terms
To understand the variables as indicators in this study, keywords are presented
to clarify the purpose and direction of the procedure. This is to ensure that a clear
description of concepts and terms as applied in this research facilitates the collection of
meaningful and standardized data. This is also to avoid variation and confusion in
interpretation.
Commercial Insecticide as Positive control (BTI). Are intended for use in
agriculture, forestry, industry, and other economic activities. It is a chemical mixture that
contains an active ingredient that kills or repels insects. It is the variable that is expected
to kill 100 percent of mosquito larvae during the experiment.
Bignay (Antidesma bunius). A genus of tropical plants belonging to the family
Phyllanthaceae, used wide world in traditional medicine for treatment of infection caused
by bacteria, fungi and viruses, and is the core component used in the conduct of the
experiment.
Mosquito larvae (Culex quinquefasciatus and Aedes aegypti). The main vector
of mosquito borne diseases and the subject of the experimentation in the larvicidal
activity of “Bignay” Antidesma bunius.