CHARACTERIZATION OF Eucheuma cottonii (GUSO SEAWEED) AND

Caulerpa lentillifera (LATO SEAWEED) AND ITS PESTICIDAL

ACTIVITY ON Leptocorisa acuta (RICE EAR HEADBUG)

A Research Presented to
The Faculty of Senior High School Department
Bacolod City National High School
Bacolod City

In Partial Fulfillment
of the Requirements for Investigation, Inquiry, Immersion
Science, Technology, Engineering, and Mathematics
(STEM) Strand

ALFRED S. REVECHE
MARIANE B. MORANTE
JERALDINE K. DONGUINES

March 2020

i
 APPROVAL SHEET

This study, entitled “CHARACTERIZATION OF Eucheuma cottonii (GUSO

SEAWEED) AND Caulerpa lentillifera (LATO SEAWEED) AND ITS
PESTICIDAL ACTIVITY ON Leptocorisa acuta (RICE EAR HEADBUG)”
prepared by the Grade 12 students of Science, Technology, Engineering, and
Mathematics, in the group comprised of JERALDINE K. DONGUINES, MARIANE
B. MORANTE, and ALFRED S. REVECHE, in partial fulfillment of the requirements
for Investigation, Inquiry, Immersion (3I’s), has been reviewed and approved for
publication.

PANEL OF EVALUATORS

KRISHA ANGELA P. GIMAY FAITH T. CARDEL

Chair Member

GWENDOLYN DELGADO SEMI NAZARENO, LPT

Member Member

LURECEL B. TIU, LPT PHILLIP RAYMUND DE OCA

Adviser Adviser

FINAL APPROVAL

SUSIE A. ARANETA, PhD

Assistant Principal II

WARLITO D. ROSAREAL
OIC, Office of the Principal IV

ii
 ACKNOWLEDGEMENT

After all the hard work, sleepless nights, exhaustion, and sacrifices during the

process had paid off. The researchers would love to express their gratitude to the people

who helped them succeed and for making this study a feasible one.

To the parents of the researchers for the trust, love, and support that they extended

towards their children, and for the support both emotion and financial. This study will not

be a success without the support of the parents.

To Mr. Philip Raymund De Oca, our Practical Researcher 2 and Capstone adviser

who’s truly accommodating and never hesitate to help and encourage researchers to

transcend and for helping in the formulation of research study.

To Ms. Lurecel Tiu, Investigation, Inquiry, Immersion (3I’s) adviser who

encourages the researchers to pursue in research and for imparting her knowledge

regarding research.

To, Mr Warlito Rosareal, the secondary principal 1V and Ms. Susie A. Araneta

Ph.D. Assistant Principal II of BCNHS for trusting and permitting the researchers to

perform the experimentation even outside the school premises.

To Dr. Gerardo Estoy who allowed the researchers to conduct the research in

PhilRice Institute and for supervising during the process and for the making the

researchers appreciate research itself. To Ms. Cheryl and the laborers of PhilRice for the

assistance. Without them the expedition of the researchers can never reach its purpose.

iii
 To Mr. Carlos R. Gerogalin Jr. Ph.D., for extending his expertise as a statistician

in helping the researchers generate the statistics.

To the panelists: Ms. Krisha Angela P. Gimay, Ms. Faith T. Cardel, Ms.

Gwendolyn Delgado, and Mr. Semi Nazareno, LPT, who have given their insights and

opinion for the improvement of the study.

To Bacolod City National High School students who voluntarily cooperate with

the researchers and helped provide the materials. Y’all are highly appreciated.

iv
 TABLE OF CONTENTS

Page
TITLE PAGE i

APPROVAL SHEET ii

ACKNOWLEDGEMENT iii

TABLE OF CONTENTS v

LIST OF TABLES vii

LIST OF FIGURES ix

ABSTRACT xi

INTRODUCTION 1

Background of the study 1

Statement of the problem 3

Hypothesis 5

Conceptual framework 5

Scope and limitation 5

Significance of the study 6

Definition of terms 7

Review of related literature 8

MATERIALS AND METHOD 16

Research design 16

v
 Materials and equipment 16

Location and duration 17

Flowchart 19

General procedure 20

Statistical analysis 25

RESULTS AND DISCUSSION 27

CONCLUSION 34

Recommendations 36

REFERENCES 37

APPENDICES 38

Pictures of the experiment 38

Data 44

CURRICULUM VITAE 46

vi
 LIST OF TABLES

Table Page

1 Phytochemical screening results of the 27

bioactive components in Lato and Guso
Seaweed Extract

2 Test for Significant Difference on the 31

Pesticidal Activity of the Different
Concentrations of Lato Seaweed Crude
Ethanol Extract, Guso Seaweed Crude
Ethanol Extract, and Cypermethrin in a
Laboratory Experiment Using One-Way
Analysis of Variance

3 Test for Significant Difference on the 32

Pesticidal Activity of the Different
Concentrations of Lato Seaweed Crude
Ethanol Extract, Guso Seaweed Crude
Ethanol Extract, and Cypermethrin in a
Field Experiment Using One-Way
Analysis of Variance

4 Mortality of Rice Earhead Bug at 44

different concentrations of Lato, Guso,
and Cypermethrin at different time
exposure for first replicate of field
experiment

5 Mortality of Rice Earhead Bug at 44

different concentrations of Lato, Guso,
and Cypermethrin at different time
exposure for second replicate of field
experiment

6 Mortality of Rice Earhead Bug at 44

different concentrations of Lato, Guso,
and Cypermethrin at different time

vii
exposure for third replicate of field
experiment

7 Mortality of Rice Earhead Bug at

different concentrations of Lato, Guso, 45
and Cypermethrin at different time
exposure for first replicate of laboratory
experiment

8 Mortality of Rice Earhead Bug at 45

different concentrations of Lato, Guso,
and Cypermethrin at different time
exposure for second replicate of
laboratory experiment

9 Mortality of Rice Earhead Bug at 45

different concentrations of Lato, Guso,
and Cypermethrin at different time
exposure for third replicate of laboratory
experiment

viii
 LIST OF FIGURES

Figure Page

1 Conceptual Framework 5

2 Flowchart of the general procedure of the study 19

3 The average mortality rate of the rice earhead bug 29

from the three replicates after 24 hours of exposure
to different concentrations of the pesticides applied
in the field experiment.

4 The average mortality rate of the rice earhead bug 30

from the three replicates after 24 hours of exposure
to different concentrations of the pesticides applied
in the laboratory experiment.

5 Guso Seaweed 38

6 Lato Seaweed 38

7 Extraction of Seaweeds 38

8 Guso Seaweed Extract 39

9 Lato Seaweed Extract 39

10 Phytochemical Screening 39

11 Mosquito Nets 40

12 Palay 40

13 Sacks 40

14 Establishment of Pest Trap 40

15 Rice Earhead Bug 41

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16 Spray Bottles 41

17 Distilled Water 41

18 Graduated Cylinder 41

19 Petri Dish 41

20 Erlenmeyer Flask 42

21 Beaker 42

22 Preparation of the Concentrations of Extract 42

23 Preparation of the Concentrations of Extract 42

24 Preparation of Laboratory Set-ups 43

25 Application of Treatments 43

x
 ABSTRACT

This study was formulated concerning the problems that the rice industry has to
overcome in able to provide sufficient supply of rice to the consumers. In conducting the
study, the researchers were able to determine various factors affecting the decrease in
rice-yield. Specifically, pests are the major problem in the rice field. As the problem on
pests become evident, the innovation on pest management emerged, which implies that
there is a need for innovation and this suggests for an efficient use of bioactive
compounds to protect the crops from chemical compounds. Pesticides have now become
an integral part of our modern life and are used to protect agricultural land, stored grain,
flower gardens as well as to eradicate the pests transmitting dangerous infectious
diseases. With that, the researchers established this study, pesticidal activity of seaweeds,
to ease the dilemma. E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) were
extracted to create pesticide with bioactive components. The extracts were applied to the
acclimated pests and observed for a day with specific time observation to accumulate the
mortality of pests, L. oratorius (Rice ear head bug), both for laboratory and field
experiment.

xi
 INTRODUCTION

Background of the study

Rice is considered as an essential food for about half of the global population

(Barrion, Joshi, Barrion-Dupo, and Sebastian, 2007). Since the rice commodity arises,

many set interests in expanding and growing the industry.

The vastness of the population affects the global demand for rice production and

it indicates that there is development in the rice commodity. However, despite the growth

of rice industry globally, there are factors to ponder which are affecting the production,

which then reflects the consumers, farmers, and rice consumption. Using statistical tools

and production function, the study found that the common problems by rice farmers

were: the high cost of inputs, low price of palay, lack of capital, labor problem, lack of

post-harvest facilities, pests and diseases, and irrigation system (‘’Problem in rice

farming’’, 2019).

Two major factors are responsible for low yields: adverse weather (floods,

drought, typhoons, etc.) and pest epidemics (M. D. Pathak and Z. R. Khan, 2014).

The damage caused by L. acuta (Thunberg), infestation was similar to that caused

by L. oratorius, empty grains being produced. Yellow spots appeared on the leaves due to

excessive sucking. The empty grains turned whitish and showing a puncture mark.

Infested spikelet and grains were found, where the infestation was severe (M.A.R.A.

Mandanayake, A.M.A. Amarakoon, U.G.A.I. Sirisena, K.S. Hemachandra, Michael R.

Wilson, and U.C. Kahawaththa, 2014). L. acuta is typically found during the flowering

stage of the rice crop, which coincides with rainfall and high humidity at the beginning of

the wet season (Reji and Chander 2007).The effect of infestation caused by rice bugs is

empty grains being produced. Serious infestation can reduce the yield by 50%.
1
 As the problems on pests become evident, the innovation on pest management

emerged. Integrated Pest Management (IPM) helps improve the quality of the crop with

the use of mechanical, biological, and chemical control measures that makes effective

and environmentally sensitive tool integrated pest management.

Chemical control pests suggest efficient use of bioactive substances to lessen

descriptive effects on the environment and plants (Rhodes Makundi, 2006). The existence

of several pest controls and the search for new compounds for pesticides implies that no

single type of pest control agent shall be expected to solve problems in rice production.

Therefore, there shall have innovation towards the use of pesticidal compounds in terms

of formulation, methods of application, forget specificity, non-persistence, and low

toxicity in the environment. (Makundi, 2006).

This study aims to discover the pesticidal activity of Eucheuma cottoni (Guso

seaweed) and Caulerpa lentillifera (Lato Seaweed) and its pesticidal activity on

Leptocorisa oratorius (Rice ear head bug).

Accordingly, pesticides need to help reduce pests in the rice field and reach the

demand of rice productivity. As such, it is in this postulate that the researchers conducted

this study to the pesticidal activity E. cottoni (Guso seaweed) and C. lentillifera (Lato

Seaweed) crude ethanol extract. Thus, the findings of this study may help different

sectors that are related to the rice industry. Moreover, the researchers conducted an

experiment with different variables such as: different concentrations, type of seaweeds,

and time exposure.

Statement of the Problem

2
 This study aimed to determine the Characterization of E. cottoni (Guso seaweed)

and C. lentillifera (Lato Seaweed) and its Pesticidal Activity on L. acuta (Rice earhead

bug).

Specifically, this study sought to answer the following questions:

1. What are the phytochemicals present in E. cottoni (Guso seaweed) and C.

lentillifera (Lato Seaweed) crude ethanol extracts?

2. What is the pesticidal activity of E. cottoni (Guso seaweed) and C. lentillifera

(Lato Seaweed) crude ethanol extract and Cypermethrin (control), through the

mortality rate of L. acuta (Rice ear head bug) according to the following

concentrations?

A. 100% C. lentillifera (Lato Seaweed)crude ethanol extract

B. 75% C. lentillifera (Lato Seaweed)crude ethanol extract, 25% of Distilled

water

C. 50% C. lentillifera (Lato Seaweed)crude ethanol extract, 50% of Distilled

water

D. 25% C. lentillifera(Lato Seaweed)crude ethanol extract, 75% of Distilled

water

E. 100% E. cottonii(Guso seaweed) crude ethanol extract

F. 75% E. cottonii(Guso seaweed) crude ethanol extract, 25% of Distilled

water

G. 50% E. cottonii(Guso seaweed) crude ethanol extract, 50% of Distilled

water

3
 H. 25% E. cottonii(Guso seaweed) crude ethanol extract, 75% of Distilled

water

I. Cypermethrin

3. Is there a significant difference in the pesticidal activity of different

concentrations of E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed)

crude ethanol extract, and Cypermethrin (control) against L. acuta (Rice ear head

bug)?

A. 100% C. lentillifera (Lato Seaweed)crude ethanol extract

B. 75% C. lentillifera (Lato Seaweed) crude ethanol extract and 25% of

Distilled water

C. 50% C. lentillifera (Lato Seaweed) crude ethanol extract and 50% of

Distilled water

D. 25% C. lentillifera (Lato Seaweed) crude ethanol extract and 75% of

Distilled water

E. 100% E. cottonii (Guso seaweed) crude ethanol extract

F. 75% E. cottonii (Guso seaweed) crude ethanol extract and 25% of

Distilled water

G. 50% E. cottonii (Guso seaweed) crude ethanol extract and 50% of

Distilled water

H. 25% E. cottonii (Guso seaweed) crude ethanol extract and 75% of

Distilled water

I. Cypermethrin

4
Hypothesis

There is no significant difference in the pesticidal activity of E. cottoni (Guso

seaweed) and C. lentillifera (Lato Seaweed) crude ethanol extract, and Cypermethrin

(control) against L. acuta (Rice ear head bug) at different concentrations.

Conceptual framework

The pesticidal activity of the lato and guso crude ethanol extract is manipulated

by independent variables namely: a. components of seaweeds b. concentration of

pesticides c. types of pesticide. These variables are to determine the mortality rate of the

rice earhead bug, which is the dependent variable.

Independent Variables Dependent Variables

Component of
Seaweeds

Concentrations of
Mortality Rate
Pesticides

Types of Pesticides

Figure 1. Conceptual Framework

Scope and limitations

This study aimed to distinguish the characterization of Lato and Guso seaweed

and its pesticidal activity against rice earhead bug. The pesticidal activity of the extracts

5
will be determined through the mortality rate of pests. The extracts are compared to

Cypermethrin, which is commercially available.

The procedure for extraction were all done in the Negros Prawn laboratory

under the supervision of the chemist. The seaweeds were washed with distilled water,

oven dried seaweeds at 40-60 °C overnight, pulverized using a blender, weighed on an

analytical balance, soaked in 70% ethanol (1:10 w/v) for 24 hours, filtered using a

cheesecloth/ filter paper, and concentrated the extract in a rotary evaporator.

There were 27 set-ups both for field experiment and laboratory experiment, each

set-up contains 10 rice earhead bug for the field experiment while there are 6 rice earhead

bugs for each set-up in the laboratory experiment. The pesticides with different

concentrations were sprayed simultaneously to every corresponding set-up at every

replicate. The mortality of pests were recorded cumulatively at a given time exposure for

at least 24 hours.

Three replicates were performed both for laboratory and field experiment to

acquire the average mortality rate of the rice earhead bug.

Significance of the study

This study may be beneficial to the following:

Farmers. This study will provide information to the farmers according to the

pesticidal activity of the extract from C. lentillifera and E. cottonii seaweeds which they

can use to eliminate pests present in the rice field to increase the rice production.

6
 Consumers. Consumers may be informed of the problems in the rice industry and

will initiate to consume rice accordingly. Since consumers are affected by the supply of

rice, they are one of the beneficiaries of this study.

Environment. The goal of this study is to produce harmful pesticide, and it also

aims to amplify the pesticidal activity of seaweed crude ethanol extracts as pesticide

which is not disruptive to the environment and crops.

Rice industry. This study is mainly formulated to assist the need of rice industry to

eliminate the pests, which reduces the rice-yield. This study will enable rice industry to

produce quality and sufficient rice supply to reach the demand.

Future Researchers. The valuable information or results of this study can help

other researchers to come up with different studies in relation to this study. Also, they can

further improve this study to a greater parameter.

Definition of terms

Characterization. Conceptually, this term refer to identify process parameter that

impact onto product quality and yield; justify manufacturing operating ranges and

acceptance criteria; identify interactions between process parameters and critical quality

attributes; ensure that the process delivers a product with reproducible yields and priority

(Thomas Zahel, 2017)

Operationally, this term refers to the features and components of Lato and Guso.

7
 Pesticidal activity. Conceptually, any agent that causes the death of a pests. The

general definition is usually restricted to chemicals with pesticidal properties, such as,

herbicides, insecticides, acaricides, and fungicides. (Saunders, J.P. Margham, 2005)

Operationally, this term refers to the act of applying pesticides on the identified

pests.

Concentration. Conceptually, it is defined as Helmenstine (2017) as the “ratio of

solute in a solution to either solvent or total solute.”

Operationally, this term refers to the ratio of Lato and Guso Seaweed crude

ethanol extract that is diluted in a distilled water.

Rice earhead bug. Conceptually, Leptocorisa acuta is a moderately large and

slender, pale species and is considered as the second major pest in rice and is found in

almost all rice growing areas of the East Asia (Mandanayake et al, 2014).

Operationally, it is used as a sample pest for experiment.

Review of related literature

This chapter includes the conceptual literature and the related studies that are

relevant to this study.

Conceptual Literature

Conceptual literature refers to the studies that contains the explanations, opinions,

and theories written by the experts concerning certain phenomenon.

8
Rice earhead bug

Leptocorisa acuta is a very damaging pest of rice and can reduce yield by as much

as 30 per cent. Nymphs are more destructive than the adults. They prefer grains at the

milky stage. Bugs damage rice by sucking the contents of developing grains from pre-

flowering to soft dough stage. Both nymphs and adults feed on grains at the milky stage.

Such grains remain empty or only partially filled. The panicles in heavy infested fields

contain many shriveled and unfilled grains and usually remain erect. An infested field can

be recognized by rice bugs severe odour. Adults are active in the late afternoon and early

morning, resting in the shaded areas (Pathak, 2007). Thus, proper pest management by

using botanicals, biopesticides and insecticide molecules is necessary to obtain a

sustainable increase in rice production. Insecticides offer a practical method of insect

control, therefore study on insecticides for the control of ear head bug was conducted

under field condition (V. P. Girish and R. A. Balikai, 2015).

Symptoms of damage of rice earhead bug

Sucking the sap from individual grains, which are in milky stage. Individual

grains become chaffy Black spots on the grains at the site of feeding puncture. Buggy

odor in rice field during milky stage Identification of insect pest: Egg: Are circular,

brownish seed like 2mm long laid in clusters in two rows along the midrib on the upper

surface of the leaf blade Nymph: First instar is small, 2mm long, pale green in color

which grows to deepen green through different instars Adult: Adults are greenish yellow,

long and slender, above ½ inch in length with a characteristics buggy odor (Jo Catindig,

2017).

9
Benefits of seaweeds

The following are the benefits if the seaweeds according to Chris Hull:

 Fertilizer. Seaweed has 60 trace minerals and ready-to-use nutrients including

nitrogen, potassium, phosphate, and magnesium. It also contains hormones to

encourage plant growth. Unlike other garden amendments, such as manure,

seaweed does not need to decompose before being a benefit to your garden.

 Mulch. Like all mulches, seaweed helps to keep soil moist thus reducing your

need to water the garden. An application of seaweed will reduce how often you

need to weed. It contains no seeds that could possibly turn into weeds as bark

mulch sometimes does. Recently I've become aware that bark mulch can be a fire

danger because it is dry and acts like kindling. Seaweed presents no such danger.

 Pest control. Slugs especially hate seaweed because of its sharp edges and salt.

Birds and other garden pests dislike it for the same reasons.

 Improved aeration. Seaweed helps aerate the soil just like peat moss does, but it

has the added benefit of delivering nutrients and minerals.

 Prevents fungus and disease. Seaweed helps you to grow strong, healthy plants,

and healthy plants resist fungus and disease.

 Doesn't blow away. Unlike other compost and mulches, seaweed (especially

when it is still wet) won't blow away in a stiff wind.

Indicators of Pesticide

10
 Numerous indicators reflect pesticides characteristics, including chemical and

physical properties, toxicological effects, hazard categories, effectiveness, importance in

use, etc. Among the available indicators, a major distinction is to be made between two

different types : Pesticide Use Indicators (PUIs): total amounts of pesticide used or total

number of sprayings ; Pesticide Risk Indicators (PRIs): a combination of hazard and

exposure characteristics for one or several environ-mental compartments (e.g. farm

worker, air, birds, earthworms) that are that are assessed separately. About 100 different

indicators have been developed until now (Van Bol et al., 2002).

Related studies

The damage caused by L. acuta (Thunberg), infestation was similar to that caused

by L. oratorius, empty grains being produced. Yellow spots appeared on the leaves due to

excessive sucking. The empty grains turned whitish and showing a puncture mark.

Infested spikelet and grains were found, where the infestation was severe (M.A.R.A.

Mandanayake, A.M.A. Amarakoon, U.G.A.I. Sirisena, K.S. Hemachandra, Michael R.

Wilson, and U.C. Kahawaththa, 2014).

Leptocorisa acuta is a moderately large and slender, pale species and is

considered as the second major pest in rice and is found in almost all rice growing areas

of the East Asia (Mandanayake et al, 2014). In Malaysia, complete loss of the crop is

reported from the areas where control measures are not applied. In the Philippines, up to

70% of the season's crop could be lost due to L. acuta attack (Lim, 2007).

According to the study entitled “Natural Products in Plant Pest Management,”

pesticides have now become an integral part of our modern life and are used to protect

11
agricultural land, stored grain, flower gardens as well as to eradicate the pests

transmitting dangerous infectious diseases. In the recent years, there has been

considerable pressure in agriculture to reduce chemical pesticides and look for their better

alternatives (N.K. Dubey, Ravindra Shukla, Ashok Kumar, Priyanka Signh, and Bhanu

Prakash, 2011). It has been estimated that globally nearly $38 billion are spent on

pesticides each year (Pan-Germany, 2012).

The absence of crop protection will lose the entire effort of growing a crop that

will result the growers to a financial loss. Hence, there is an urgent need to provide

attention to control the quantitative losses due to pest infestations of crops and their

produce (N.K. Dubey et al, 2011).

On the other hand, pesticides that are used to kill infesting pests possess inheret

toxicities that endanger the health of the farmers, consumers, and the environment (Cutler

and Cutler, 1999). The excessive use of synthetic pesticides in the croplands, urban

environment, and water bodies to get rid of noxious pests has resulted in an increased risk

of pesticide resistance, enhanced pest resurgence and development of resistance/cross-

resistance, toxicological implications to human health and increased environmental

pollution. In fact, combating of environmental pollution and its ill-effects on the life and

life- support systems is one of the most serious challenges before the present day world.

Efforts are thus being made world over to replace these synthetic chemicals with

alternatives, which are safer and do not cause any toxicological effects on the

environment. The natural pest and disease control either directly or indirectly using

natural plant products/botanicals, including essential oils, holds a good promise

(Regnault-Roger, 1997; Isman, 2000, 2006; Bakkali et al., 2008).

12
 Hence, manufacturers and researchers are designing new formulations of

pesticides to meet the global demand. Ideally, the applied pesticides should only be toxic

to the target organisms, should be biodegradable and eco-friendly to some extent (Rosell

et al., 2008).

Based on the study entitled “Pesticides Classification and Its Impact on Human

and Environment” by (Ishwar Chandra Yadav and Ningombam Linthoingambi DeVI,

2017) there are several ways pesticides come in contact with or enter the target are called

modes of entry. These include systemic, contact, stomach poisons, fumigants, and

repellents.

Fumigants are such pesticides which acts or may kill the target pests by producing

vapor. These pesticides form poisonous gases when applied. These pesticides in vapor

form enter the body of pests via their tracheal system (respiratory) through spiracles and

causes death by poisoning. Some of their active ingredients are liquids when packaged

under high pressure but change to gases when they are released. Other active ingredients

are volatile liquids when enclosed in an ordinary container and are not formulated under

pressure (Ishwar Chandra Yadav et al, 2017). Hence, the rice earhead bug were killed

through the respiratory system by the odor and aroma of the Lato and Guso seaweed

crude ethanol extract. Therefore, Lato aand Guso seaweed crude ethanol extracts were

classified into Fumigants pesticides in terms of mode of entry.

Also based on the study entitled “Pesticides Classification and Its Impact on

Human and Environment”, based on sources of origin, pesticide may be classified into

chemical pesticide and bio-pesticides. The third class is Biochemical pesticides which

include natural materials that have nontoxic mechanisms to control pests. Examples of

13
Biochemical pesticides are insect sex pheromones (act by interfering in mating), a range

of aromatic plant extracts (work by attracting insect pests into traps) (Ishwar Chandra

Yadav et al, 2017).

In comparison to the components of the Lato and Guso seaweed, which are

Alkaloids, Tannins, Phenols,Flavonoids, and Terpenoids, the study of “Eucalyptus

Essential Oil as A Natural Pesticide” by Daizy R. Batish, Harminder Pal Singh, Ravinder

Kumar Kohli, Shalinder Kaur (2008), plant essential oils are obtained from non-woody

parts of the plant, particularly foliage, through steam or hydrodistillation. They are

complex mixture of mainly terpenoids, particularly mono- terpenes (C10) and

sesquiterpenes (C15), and a variety of aromatic phenols, oxides, ethers, alcohols, esters,

aldehydes and ketones that determine the characteristic aroma and odour of the donor

plant. Presence of volatile monoterpenes or essential oils in the plants provides an

important defense strategy to the plants, particularly against herbivorous insect pests and

pathogenic fungi (Langenheim, 1994). These volatile terpenoids also play a vital role in

plant–plant interactions and serve as attractants for pollinators (Tholl, 2006). They act as

signaling molecules and depict evolutionary relationship with their functional roles

(Theis and Lerdau, 2003).

Aromatic plants and their essential oils have been used since antiquity in flavor

and fragrances, as condiment or spice, in medicines, as antimicrobial/insecticidal agents,

and to repel insect or protect stored products (Dorman and Deans, 2000; Isman and

Machial, 2006; Bakkali et al., 2008). These constitute effective alternatives to synthetic

pesticides without producing adverse effects on the environment (Isman, 2000; Isman and

Machial, 2006). However, the attempts to characterize their pest control activity under in

14
vitro conditions started in 1900s (Dorman and Deans, 2000). Moreover, the interest in

essential oils has regained momentum during the last decade, primarily due to their

fumigant and contact insecticidal activities and the less stringent regulatory approval

mechanisms for their exploration due to long history of use (Isman, 2006). Of late, the

essential oils are being tried as potential candidates for weed (Singh et al., 2003; Batish et

al., 2004).

15
 MATERIALS AND METHODS

This chapter deals with the approach of research design, materials and equipment,

location and duration, and flowchart.

Research Design

In the conduct of this research project, two basic steps of investigation were

employed, the phytochemical screening (qualitative), and the mortality rate was used to

determine the pesticidal activity of the Lato and Guso Seaweed crude ethanol extract.

Specifically, this research study employed a descriptive research design in

determining the phytochemicals present in Guso and Lato Seaweed, and mean was

acquired through adding the mortality rate of the rice earhead bug of three replicates then

dividing it by the three. The One-Way Analysis of Variance or ANOVA was used to

determine the significant difference between the concentrations of the extracts. Also,

Two-Way Analysis of Variance or ANOVA was used to determine the significant

difference between the concentrations of Lato Seaweed, Guso Seaweed, and

Cypermethrin.

Materials and Equipment 

This study was conducted using the following materials and equipments:

16
 The E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) were bought

with every sample weighing 5 kilograms. 14 pieces of mosquito nets and 14 pieces of

sacks were cut into half to obtain a total of 28 pieces each. Distilled water, 2 rolls of

straw ropes, and 10 spray bottles were purchased while 28 pieces of pails were borrowed

from the researchers’ schoolmates, and 108 bamboos and 2 sweep nets were obtained

from the laborers of PhilRice, Negros Cansilayan, Murcia.

For the extraction of seaweed, the researchers used the following: Blender for

pulverizing of seaweeds, analytical balance for weighing 70% ethanol where the

seaweeds are soaked, and filtered using a cheesecloth/filter paper. The Soxhlet apparatus

was used to extract E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) through

evaporation and condensation while the rotary evaporator was used to accumulate the

pure extract of Eucheuma cottoni (Guso seaweed) and Caulerpa lentillifera (Lato

Seaweed) and to separate the alcohol in the extract.

During the Phytochemical Screening, the researchers used test tubes, mechanical

pipette, and test tube rack. Distilled water, Eucheuma cottoni (Guso seaweed) and

Caulerpa lentillifera (Lato Seaweed) extracts. 

In the laboratory experiment, the researchers used test tubes, beaker, graduated

cylinders, distilled water, Eucheuma cottoni (Guso seaweed) and Caulerpa lentillifera

(Lato Seaweed), and twenty-eight (28) petri dish.

Location and Duration of the Study

The researchers purchased the E. cottoni (Guso seaweed) and C. lentillifera

(Lato Seaweed) from Libertad Public Market, Bacolod City, Negros Occidental. The

17
procedure for extraction were all done in the Neg Prawn laboratory under the supervision

of the chemist. The seaweeds were washed with distilled water, oven dried seaweeds at

40-60 °C overnight, pulverized using a blender, weighed on an analytical balance, soaked

in 70% ethanol (1:10 w/v) for 24 hours, filtered using a cheesecloth/ filter paper, and

concentrated the extract in a rotary evaporator.

After the tests and extraction of seaweeds, its extracts were then brought to

PhilRice. The preparation for different concentrations was done in the laboratory of the

PhilRice, Negros Cansilayan, Murcia. Also, the pests used as samples were taken and

acclimatized in the PhilRice, Negros Cansilayan, Murcia, where the researchers prepared

their set-ups. The researchers then applied the treatments to the pests simultaneously.

Gathering of Materials

Extraction of Seaweed

Characterization of Seaweed

Preparation
75% extractof Different
and 50%Concentration
extract and 25% extract and
100% extract (both
25% distilled water 50% distilled water 75% distilled water
for Lato and Guso
(both for Lato and (both for Lato and (both for Lato and
Seaweed)
Guso Seaweed) Guso Seaweed) Guso Seaweed)

Field Experiment
Establishment of Acclimation of Application of
Collection of Pests
Pest Traps Pests Treatment

18

Laboratory Experiment
 Mortality Rate

FLOWCHART

Statistical Analysis

General Procedure

A. Gathering of Materials   

The researchers gathered the materials such E. cottoni (Guso seaweed) and C.

lentillifera (Lato Seaweed), each weighing 5 kg, from Libertad Public Market, Bacolod

City, Negros Occidental. Distilled water was bought from Negros Grace Pharmacy in

Bacolod City, Negros Occidental while 14 pieces of mosquito nets were bought from

SKG Shopping Plaza in Bacolod City, Negros Occidental. 10 pieces of spray bottles were

purchased from Gaisano Mall Bacolod, Bacolod City, Negros Occidental while 28 pails

were borrowed from students of Bacolod City National High School, 2 rolls of straw

ropes were also purchased. 108 bamboo sticks, 14 sacks, and 2 sweep nets were provided

by the laborers of PhilRice.

B. Extraction of Eucheuma cottonii (Guso seaweed)and Caulerpa lentillifera Lato

Seaweed

The E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) were washed

first using distilled water and then air-dried. Then, oven dried with the temperature of 40-

60 °C overnight. After which, seaweeds were pulverized with the use of blender. The

plant samples were weighed in an analytical balance. Soaked in 70% ethanol (1:10 w/v)

dilution for 24 hours. The soaked plant sample was filtered and heated through Rotary

Evaporator at 40°-60° for the final extract.Then, filtered using a cheesecloth/filter paper.

Used the rotary evaporator for two (2) – three (3) hours to accumulate the pure extract of

19
 E. cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed). The rotary evaporator was

used to separate the alcohol in our extract and get the pure extract.

C. Characterization of Seaweeds

To determine the bioactive compounds present in Eucheuma cottoni (Guso

seaweed) and Caulerpa lentillifera (Lato Seaweed) crude ethanol extracts, the

phytochemical screening method was utilized. 

Test for Saponins

Foam test. 1 ml solution of each plant extract was diluted with 5 ml distilled water

then shaken in a test tube vigorously and observed for a continued stable frothing. 1 ml

extract was treated with 1% lead acetate solution. Formation of white precipitate

indicates the presence of saponins. (Devmurari V P et al., 2010).

Test for Tannins

Ferric Chloride test. 1 ml solution of each plant extract were taken in water,

warmed and filtered. Two drops of ferric chloride were added and observed for a

greenish to black coloration as an indication of tannins.

Test for Alkaloids

Mayer’s test. About 1 ml of each plant extract was mixed with sulfuric acid

warmed and filtered. After that, 2 drops of Mayer’s reagent were added. The formation of

creamy white precipitate was observed.

Test for Flavonoids

Hydrogen chloride test. 1 ml of each plant extract was added with 3 drops of HCI.

Development of red to black coloration was observed.

20
 Test for Terpenoids

Salkowski test. 1 ml of each plant extract was mixed with 2 ml of chloroform and

3 ml of sulfuric acid to form a layer. A reddish-brown interface was an indication of

presence of terpenoids.

Test for Glycosides

Keller-Kiliani test. About 1 ml of each plant extract was dissolved in glacial

acetic acid and cooled, after cooling, 5% of ferric chloride was added. Sulfuric acid was

added to this solution carefully along the walls of the test tube. Bluish green coloration

was observed in the upper layer while a brownish red coloration was observed in the

lower layer indicates the presence of glycosides. 

Test for Proteins

Biuret test.  About 1 ml of each plant extract was mixed with 2 ml of sodium

hydroxide (10%) and 1% of copper sulfate. Development of purple and pink coloration

was observed. 

Test for Carbohydrates

Benedict’s test. 1 ml of each plant extract was mixed with Benedict’s reagent ang

then boiled for 5 minutes. A formation of brick red coloration was observed, an

indication of presence of carbohydrates.

Test for Phenols

21
 Ferric Chloride test.  About 1 ml of each plant extract was added with ferric

chloride. Development of brown to black coloration, an indication of presence of

phenols.

D. Preparation of the Extract Concentration

Ten (10) spray bottles were prepared containing 4 different concentration both for

Lato seaweed extracts and Guso seaweed extracts. The treatment contains 100% extract

(both for Lato and Guso Seaweed), 75% extract and 25% distilled water (both for Lato

and Guso Seaweed), 50% extract and 50% distilled water (both for Lato and Guso

Seaweed), 25% extract and 75% distilled water (both for Lato and Guso Seaweed).

E. Field Experiment

There are three (3) replicates prepared for each treatment. The mortality were

recorded after the exposure time 1hr, 3 hrs, 6 hrs, 12 hrs, and 24 hrs cumulatively. In

conducting the field experiment the following procedures were observed:

E.1 Establishment of Pest Trap

The researchers first harvested 28 rice plants from the rice fields at PhilRice,

Negros Cansilayan, Murcia and placed it inside the corresponding number of pails. The

54 pieces of bamboo obtained were cut into half using sugarcane machete that give an

amount of 108 pieces. 14 pieces of used sacks were then gathered and cut into half with

the use of scissors that gives a total 28 pieces. 14 pieces of mosquito net were also cut

into half using scissors, obtaining an amount of 28 pieces. 

22
 In the building of the pest trap, first the sack was laid down on the ground then the

pail with rice plant was placed on top. Then it was covered using the mosquito net held

down on the four corners using the sharp end of the bamboo sticks and tied around with

the use of four straw ropes.

Pest traps were used to acclimatize the pests for 24 hours.

E.2 Collection of Pest

The researchers collected rice earhead bugs from the rice field with the use of

sweep nets. 10 pests were collected for each traps. At least 270 pests were collected for

field experiment.

E.3 Acclimation of Pest

The pests were acclimated for 24 hours to adjust in their new environment before

applying the treatment to determine if the pests died because of the treatment and not

because of their unusual environment.

E.4 Application of treatment

The treatment of different concentrations were applied directly to the pests,

simultaneously.

F. Laboratory Experiment

The bioassay activity was conducted at PhilRice, Negros Cansilayan, Murcia

Laboratory building. The activity culminated by setting up twenty-eight (28) Petri dishes,

each were filled with ten (10) rice bugs. There are three (3) replicates prepared for each

treatment. The mortality were recorded after the exposure time 1hr, 3 hrs, 6 hrs, 12 hrs,

23
 and 24 hrs cumulatively. In conducting the laboratory experiment the following

procedures were observed:

F.1 Preparation of Petri dish

28 petri dish were placed on a table each were labeled accordingly with

different concentration and cotton balls were placed inside each petri dish to make sure

that the mortality is caused by the treatment and not because the pests were drown into

the amount of treatment.

F.2 Collection of Pests

6 pests were collected for each petri dish and they were placed inside and

covered. At least 162 pests were collected for laboratory experiment.

F.3 Application of Treatment

The treatment of different concentrations were applied directly to the pests,

simultaneously.

G. Mortality Rate

Mortality rate of pests were recorded at different time exposure for at least 24

hours after the application of different concentrations of pesticide. Frequency of mortality

rate were observed through the three replicates.

Mortality rate were acquired through dividing the mortality to the total population

of the acclimated pests and multiplied by 100.

The average mortality rate were solved by adding the mortality rate from three

replicated then divided by three (3).

H. Statistical Analysis

24
 The researchers sought for a registered statistician to analyze and evaluate the

result of the study.

To answer objective 1, which is to determine the characterization of Lato and

Guso crude ethanol extract, descriptive analysis was performed through phytochemical

screening.

To answer objective 2, which is to determine pesticidal activity of different

concentrations of E. cottoni (Guso seaweed), C. lentillifera (Lato Seaweed) crude

ethanol, and Cypermethrin (control), through the mortality rate of L. acuta (Rice ear head

bug) according to the following concentrations: A. (100% Lato Seaweed crude ethanol

extract), B. (75% Lato Seaweed crude ethanol extract + 25% of Distilled water), C. (50%

Lato Seaweed crude ethanol extract + 50% of Distilled water), D. (25% Lato Seaweed

crude ethanol extract + 75% of Distilled water), E. (100% Guso seaweed) crude ethanol

extract), F. (75% Guso seaweed crude ethanol extract + 25% of Distilled water), G. (50%

Guso seaweed crude ethanol extract + 50% of Distilled water), H. (25% Guso seaweed

crude ethanol extract + 75% of Distilled water), I. (Cypermethrin). The mortality rate was

computed by dividing the recorded mortality of pests after 24 hours of exposure by the

total population of pest in a trap then multiplied by 100.

The mortality rate for three replicates were added then divided by three to acquire

the average mortality rate of the pest in for each concentrations.

To answer objective 3, which is to determine if there will be a significance

difference between the different concentrations of Lato seaweed crude ethanol extract,

Guso seaweed crude ethanol extract, and control, the One-Way Analysis of Variance or

ANOVA was used.

25
 RESULTS AND DISCUSSION

This chapter presents the results, analysis, and interpretation of the data collected

in the study experiment conducted by the researchers which aims to determine the

characterization of the Lato and Guso seaweed and its pesticidal activity on rice earhead

bug.

The Characterization of Lato and Guso Seaweed through Phytochemical Screening

Table 1 shows the phytochemical screening of the Lato and Guso Seaweed to

determine the bioactive components present in the Lato and Guso Seaweed to potentially

kill the pests.

Table 1

Phytochemical screening results of the bioactive components in Lato and Guso Seaweed
Extract
Test Guso Extract Lato Extract Positive Reaction
Alkaloids + + Creamy white Precipitate
Tannins _ + Green-black Precipitate

26
 Saponin _ _ Continued Frothing
Proteins _ _ Violet Pink Precipitate
Phenols _ + Bluish Precipitate
Flavonoids + + Black Precipitate
Glycoside _ _ Upper layer-bluish-green
color
Lower layer-brownish-red
color
Carbohydrates _ _ Reddish Brown Precipitate
Terpenoids + + Dark Brown black
precipitate

The result shows that both Lato and Guso extract contains Alkaloids, Flavonoids,

and Terpenoids. On the other hand, only Lato extract contains Tannins and Phenols.

Phenolics consist of an aromatic ring with one or more hydroxyl groups (Showket

A. Dar*, Bashir A. Rather; Abdul R. Wani and Mushtaq A.Ganie 2017). Supported by

(Dorman and Deans, 2000; Isman and Machial, 2006; Bakkali et al., 2008) that aromatic

plants and their essential oils have been used since antiquity in flavor and fragrances, as

condiment or spice, in medicines, as antimicrobial/insecticidal agents, and to repel insect

or protect stored products. These constitute effective alternatives to synthetic pesticides

without producing adverse effects on the environment (Isman, 2000; Isman and Machial,

2006).

Moreover, according to (Jorg Bohlmann, 2008) that terpenoids are used as

defense against insects and pathogens by conifers. In addition, the volatile fraction of

terpenoids predominantly consists of the hemiterpene isoprene (C5), monoterpenes (C10)

and sesquiterpenes (C15) and their derivatives such as homoterpenes (C11 and C16).

Monoterpenes and sesquiterpenes are synthesized by the condensation of two or three

isoprene units, respectively (Cheng et al. 2007). Because of their physicochemical

27
properties, such as volatility, reactivity, toxicity and aroma, many protective functions

against abiotic and biotic factors have been ascribed to terpenoids (Holopainen 2004). In

regards to that, both Lato and Guso Seaweeds possess terpenoids.

Therefore, the mortality of pests was induced by the phenols and terpenoids,

which produces aroma and odor that kill the pests.

The Average Mortality Rate of Rice Earhead Bug from the Three (3) Replicates

after 24 Hours Exposed to Different Concentrations of E. Cottoni (Guso Seaweed)

and C. Lentillifera (Lato Seaweed) Crude Ethanol Extract, and Cypermethrin

(Control)

Figure 3

The average mortality rate of the rice earhead bug from the three replicates after 24
hours of exposure to different concentrations of the pesticides applied in the field
experiment.

28
 80%
70.00%
70% 66.67%
63.33%
AVERAGE MORTALITY RATE OF RICE EARHEAD BUG 60%

50%
43.33%

40% 36.67%

30% 26.67%

20% 16.67%
13.33%

10%
3.33%

0%
n
TO TO TO TO SO SO SO SO ri
LA LA LA LA U U U U h
% % % %
G G G G et
0 5 0 5 % % % % m
0 0 5 0 5 er
1  7  5  2 0 7 5 2
              1             yp
          
      
                   
      
       C
    · · ·     ·  ·  · 
·  · 

CONCENTRATIONS OF EXTRACT

The result of the average mortality rate of the pesticides from the three replicates

shows that the 100% concentration of Lato seaweed crude ethanol extract generated the

highest average mortality rate of 70% while the 25% concentration of Lato seaweed

crude ethanol extract has the lowest average mortality rate of 3.33%.

The result implies that the mortality rate varies in every concentration. The

mortality rate will further determine the efficacy of the pesticides and what specific

concentration is the most effective.

Figure 4

The average mortality rate of the rice earhead bug from the three replicates after 24
hours of exposure to different concentrations of the pesticides applied in the laboratory
experiment.

29
 120%

100% 100% 100% 100% 100% 100%

100% 94%

AVERAGE Mortality rate of rice earhead bug

80%

61%
60%
44%
40%

20%

0%
to to to to so so so so ri
n
La La la la gu gu gu gu h
% et
0
%
5% 0 5% 0
%
5% 0% 5
%
m
0 7 5 2 0 7 5 2 er
1             1    
 
   
 
   
 
yp
          
 
   
 
   
       ·  ·                C
   ·       ·  ·  · 
·  ·

concentrations of EXTRACT

The graph shows that the 100%, 75%, 50% and 25% concentrations of Lato

seaweed crude ethanol extract has 100% average mortality rate. This implies that in a

laboratory experiment, the concentrations of Lato seaweed crude ethanol do not vary in

terms of its outcome. Also, the 100% and 75% concentrations of Guso seaweed crude

ethanol extract has 100% average mortality which indicates that both treatment have the

same efficacy. On the other hand, the lowest average mortality rate is evident in 25%

concentration of Guso seaweed crude ethanol extract which is 44.44%.

Significant Difference in the Pesticidal Activity of Different Concentrations of Guso

Seaweed Seaweed Crude Ethanol Extract, Lato Seaweed Crude Ethanol Extract

and Cypermethrin against Rice Earhead Bug

30
 The third objective of this study was to determine if there is a significant

difference between the concentrations of the Lato and Guso Seaweed crude ethanol

extract, and the commercially available pesticide after 24 hours of exposure.

Table 4 shows the result of the One-way ANOVA for Lato Seaweed crude

ethanol extract at different concentration applied in a laboratory experiment.

Table 2
Test for Significant Difference on the Pesticidal Activity of the Different Concentrations
of Lato Seaweed Crude Ethanol Extract, Guso Seaweed Crude Ethanol Extract, and
Cypermethrin in a Laboratory Experiment Using One-Way Analysis of Variance
Standard
 Grouping Variables Mean Deviation F-statistic p-value Decision
a
100% Control .6111 .51503 12.411 .000 Reject H0
100% Lato 1.0000b .51503    
b
100% Guso 1.0000 .51503
75% Lato 1.0000b .51503
b
75% Guso 1.0000 .51503
50% Lato 1.0000a .51503
c
50% Guso .9444 .51503
25% Lato 1.0000b .51503
d
25% Guso .4444 .51503      

The result on table 2 shows that the p-value between the concentrations of Lato

seaweed crude ethanol extract, Guso seaweed crude ethanol extract, and control is .000

which is lesser than 0.05 that implies that there is a significant difference and the

hypothesis which is “There is no significant difference in the pesticidal activity of E.

cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) crude ethanol extract in

comparison to Cypermethrin (control) against L. acuta (Rice ear head bug) at different

concentrations” is rejected. Therefore, the concentrations affect the mortality rate of the

rice earhead bug when applied in the laboratory experiment.

As shown in the result, these are the following concentrations having significant

difference from each other: 100% Lato and 100% Control, 100% Lato and 25% Guso,

31
100% Guso and 100% Control, 100% Guso and 25% Lato, 100% Guso and 25% Guso,

100% Control and 75% Lato, 100% Control and 75% Guso, 75% Lato and 25% Guso,

75% Guso and 25% Lato, 75% Guso and 25% Guso, 50% Lato and 25% Guso, 50%

Guso and 25% Guso, 25% Guso and 25% Lato. Therefore, these concentrations having

significant difference when compared between each other may affect the mortality rate of

the rice earhead bug.

Table 3
Test for Significant Difference on the Pesticidal Activity of the Different Concentrations
of Lato Seaweed Crude Ethanol Extract, Guso Seaweed Crude Ethanol Extract, and
Cypermethrin in a Field Experiment Using One-Way Analysis of Variance
Standard
 Grouping Variables Mean Deviation F-statistic p-value Decision
a
100% Control .4333 .68421 11.864 .000 Reject H0
100% Lato .7000a .68421    
a
100% Guso .6667 .68421
75% Lato .6333a .68421
a
75% Guso .3667 .68421
50% Lato .2667a .68421
a
50% Guso .1667 .68421
25% Lato .0333b .68421
c
25% Guso .1333 .68421      

The result on table 3 shows that the p-value between the concentrations of Lato

seaweed crude ethanol extract, Guso seaweed crude ethanol extract, and control is .000

which is lesser than 0.05 that implies that there is a significant difference and the

hypothesis which is “There is no significant difference in the pesticidal activity of E.

cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) crude ethanol extract in

comparison to Cypermethrin (control) against L. acuta (Rice ear head bug) at different

concentrations” is rejected. Therefore, the concentrations affect the mortality rate of the

rice earhead bug when applied in the laboratory experiment.

32
 As shown in the result, these are the following concentrations having significant

difference from each other: 100% Lato and 50% Lato, 100% Lato and 50% Guso, 100%

Lato and 25% Lato, 100% Lato and 25% Guso, 100% Guso and 75% Guso, 100% Guso

and 50% Lato, 100% Guso and 50% Guso, 100% Guso and 25% Lato, 100% Guso and

25% Guso, 100% Control and 25% Lato, 100% Control and 25% Guso, 75% Lato and

50% Lato, 75% Lato and 50% Guso, 75% Lato and 25% Lato, 75% Lato and 25% Guso,

75% Guso and 25% Lato. Therefore, these concentrations having significant difference

when compared between each other may affect the mortality rate of the rice earhead bug.

CONCLUSION

The study presented the conclusion drawn from the results and the findings of the

study. Recommendations are also presented to address the concerns regarding the

improvement of the parameters of the study.

33
 This study was conducted primarily to determine the Characterization of E.

cottoni (Guso seaweed) and C. lentillifera (Lato Seaweed) and its Pesticidal Activity on

L. acuta (Rice earhead bug). The characterization of seaweeds were recognized through

phytochemical screening. On the other hand, the pesticidal activity of the seaweeds were

determined through the mortality rate of the pests. Since the sample pests were flying

insects, the researchers prepared pesticides in a form of extract and place it in bottle

spray. Also, this type of pest is typically found during the flowering stage of the rice

crop, which coincides with rainfall and high humidity at the beginning of the wet season

(Reji and Chander 2007), the researchers collected them during that season.

Caulerpa lentillifera (Lato Seaweed) and Eucheuma cottonii (Guso seaweed)

cruede ethanol extracts possess pesticidal properties against rice ear head bug since they

have bioactive components that has the potential to kill pests.

Based on the phytochemical screening, the Lato Seaweed has a bioactive

component which is Phenols. Phenolics consist of an aromatic ring with one or more

hydroxyl groups (Showket A. Dar*, Bashir A. Rather; Abdul R. Wani and Mushtaq

A.Ganie 2017). Supported by (Dorman and Deans, 2000; Isman and Machial, 2006;

Bakkali et al., 2008) that aromatic plants and their essential oils have been used since

antiquity in flavor and fragrances, as condiment or spice, in medicines, as

antimicrobial/insecticidal agents, and to repel insect or protect stored products. These

constitute effective alternatives to synthetic pesticides without producing adverse effects

on the environment (Isman, 2000; Isman and Machial, 2006).

Moreover, according to (Jorg Bohlmann, 2008) that terpenoids are used as

defense against insects and pathogens by conifers. In addition,The volatile fraction of

34
terpenoids predominantly consists of the hemiterpene isoprene (C5), monoterpenes (C10)

and sesquiterpenes (C15) and their derivatives such as homoterpenes (C11 and C16).

Monoterpenes and sesquiterpenes are synthesized by the condensation of two or three

isoprene units, respectively (Cheng et al. 2007). Because of their physicochemical

properties, such as volatility, reactivity, toxicity and aroma, many protective functions

against abiotic and biotic factors have been ascribed to terpenoids (Holopainen 2004).

Hence, both Lato and Guso Seaweeds possess terpenoids.

This implies that phenols and terpenoids are the components of Guso and Lato

seaweed crude ethanol extract that are responsible in killing the pest.

The potential of seaweeds to kill pests specifically the insect pests in the rice field

is expected to decrease the infestation of pests and its disruptive effects on rice and to

increase the rice-yield twice as it is producing to supply sufficiently to the consumers.

Recommendations

Based on the result of this study, the researchers would like to suggest future

researchers to further study the following:

Lethal Concentration (LC50), Lethal Time 50 (LT50) and Lethal Dose 50

(LD50). This is to evaluate the toxicity of the pesticide which the researchers fail to do.

Other pests for sample. The researchers limited the sample used to rice earhead

bug and other pests were not evaluated. This leaves future researchers for improvement.

Range Finding Test. The researchers were able to prepare different

concentrations both for Lato and Guso seaweed crude ethanol extract namely: 100%,

75%, 50% and 25% concentrations and that future researchers should evaluate further of

35
other concentrations to determine the specific concentration that affects the mortality

rate of the pests.

36
 REFERENCES

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Michael R. Wilson, and U.C. Kahawaththa (2014) Occurrence of
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37
 APPENDICES

Pictures of the experiment

Figure 5. Guso Seaweed

Figure 7. Extraction of Seaweeds

Figure 6. Lato Seaweed

38
Figure 8. Guso Seaweed Extract Figure 9. Lato Seaweed Extract

Figure 10. Phytochemical Screening

39
Figure 11. Mosquito nets Figure 13. Sacks

Figure 12. Palay Figure 14. Establishment of Pest Trap

40
Figure 15. Rice Earhead Bug Figure 16. Spray Bottles

Figure 17. Distilled Water Figure 18. Graduated Cylinder

Figure 19. Petri Dish

41
Figure 20. Erlenmeyer Flask Figure 21. Beaker

Figure 22. Preparation of the Figure 23. Preparation of the

Concentrations of Extract Concentrations of Extract

42
Data
Time LATO GUSO Control
exposur
e
(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 0 0 0 0 1 0 1 0 0
3 0 1 1 0 1 0 1 0 3
6 5 1 1 0 6 1 1 1 3
12 6 2 3 0 7 1 2 1 3
24 7 3 3 0 7 2 2 1 3
Table 4. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for first replicate of field experiment

Time LATO GUSO Control

exposure

(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 0 0 0 0 5 1 0 0 1
3 3 2 0 0 5 2 1 0 3
6 4 6 1 0 6 4 1 2 4
12 5 8 1 0 7 4 1 2 5
24 5 9 1 0 7 4 1 2 5
Table 5. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for second replicate of field experiment

Time LATO GUSO Control

exposur
e
(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 1 1 0 0 1 1 1 0 1
3 4 5 1 0 4 3 2 0 2
6 8 6 3 0 5 4 2 1 4
12 8 6 3 1 6 4 2 1 4
24 9 7 4 1 6 5 2 1 5
Table 6. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for third replicate of field experiment

43
 Time LATO GUSO Control
exposure
(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 3 1 1 2 4 3 2 1 3
3 6 6 2 4 6 6 4 3 3
6 6 6 4 4 6 6 4 3 3
12 6 6 6 5 6 6 4 3 3
24 6 6 6 6 6 6 5 3 3
Table 7. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for first replicate of laboratory experiment

Time LATO GUSO Control

exposure
(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 3 2 1 3 5 3 2 1 2
3 6 5 5 3 6 6 6 2 5
6 6 6 6 3 6 6 6 2 5
12 6 6 6 5 6 6 6 2 5
24 6 6 6 6 6 6 6 2 5
Table 8. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for second replicate of laboratory experiment

Time LATO GUSO Control

exposure
(hour) 100% 75% 50% 25% 100% 75% 50% 25% 100%
1 4 1 3 2 6 5 2 0 1
3 5 4 4 2 6 6 4 0 2
6 6 6 6 2 6 6 6 1 2
12 6 6 6 5 6 6 6 1 2
24 6 6 6 6 6 6 6 3 3
Table 9. Mortality of Rice Earhead Bug at different concentrations of Lato, Guso, and
Cypermethrin at different time exposure for third replicate of laboratory experiment

MARIANE B. MORANTE
Prk. Tangke, Brgy. Pandanon Silos
Murcia, Negros Occidental, Philippines
44
marianeb.morante@gmail.com
09956258772
PERSONAL DATA
Age : 18
Date of Birth : September 21, 2001
Religion : Roman Catholic
Height : 5’1
Status : Single
Citizenship : Filipino
Father’s Name : Ronnie B. Morante
Occupation : Driver
Mother’s Name : Judy B. Morante
Occupation : Housewife

Skills/Talents/Hobbies:
I’m not into dancing but in terms of singing…(nevermind) I’m fond of solving math
problems anyway. I don’t want to brag about it but I’m into writing Editorial articles,
poems and diaries, which I only keep for myself, definitely.

SCHOLASTIC RECORDS
Bacolod City National HS Senior High Science, Technology,
Engineering and
Mathematics
Graduated April 2019
WITH HONORS

Lopez Jaena National HS Junior High Graduated April 2018

WITH HONORS

Lopez Jaena Elementary School Primary Graduated April 2014

VALEDICTORIAN

ACHIEVEMENT/ AWARDS/ ACTIVITIES

45
SENIOR HIGH:
WITH HONORS Grade 12 Graduation S.Y. 2019-2020
Participant Collaborative Desktop S.Y. 2019-2020
Publishing
3rd Place Division Scilympics S.Y. 2019-2020
WITH HONORS Grade 11 Recognition S.Y. 2018-2019
Member SCIEMATICOS Club S.Y. 2018-2020
Participant Editorial Writing S.Y. 2018-2019

JUNIOR HIGH:

WITH HONORS Grade 10 Recognition S.Y. 2017-2018

Member QRT (Quick Response Team)S.Y. 2017-2018
1st Place Math jingle (LJNHS) S.Y. 2017-2018
4th Place Editorial Writing S.Y. 2017-2018
Participant Editorial Writing (RSPC) S.Y. 2017-2018
13th Place MTAP S.Y. 2017-2018

WITH HONORS Grade 9 Recognition S.Y. 2016-2017

Participant Sabayang Pagbigkas(LJNHS)S.Y. 2016-2017
Participant Verse Choir S.Y. 2016-2017
WITH HONORS Grade 8 Recognition S.Y. 2015-2016
Participant MTAP S.Y. 2015-2016
WITH HONORS Grade 7 Recognition S.Y. 2014-2015
Participant MTAP S.Y. 2014-2015

PRIMARY:

VALEDICTORIAN Grade 6 Graduation S.Y. 2013-2014

10th Place Editorial Writing (DSPC) S.Y. 2013-2014
1st Place Editorial Writing (RSPC) S.Y. 2013-2014
Participant Editorial Writing (NSPC) S.Y. 2013-2014
WITH HONORS Grade 5 Recognition S.Y. 2012-2013
Participant MTAP S.Y. 2012-2013
WITH HONORS Grade 4 Recognition S.Y. 2011-2012
Participant MTAP S.Y. 2011-2012
WITH HONORS Grade 3 Recognition S.Y. 2010-2011
Participant MTAP S.Y. 2010-2011
3rd Place English Quiz Bee S.Y. 2010-2011
WITH HONORS Grade 2 Recognition S.Y. 2009-2010
Participant MTAP S.Y. 2009-2010
WITH HONORS Grade 1 Recognition S.Y. 2008-2009

46
 JERALDINE K. DONGUINES
Prk. Lacson, Brgy. Silos
Murcia, Negros Occidental, Philippines
Jelaidonguines@gmail.com
09121454035

PERSONAL DATA
Age : 17
Date of Birth : April 9, 2002
Religion : Roman Catholic
Height : 5’2
Status : Single
Citizenship : Filipino
Father’s Name : Jason M. Donguines
Occupation : Driver
Mother’s Name : Divina K. Donguines
Occupation : Teacher

Skills/Talents/Hobbies:
I love singing and listening to music. I also love reading stories in Wattpad. My skills are
memorizing song lyrics and cooking. Additionally, I have this skills of staying up late
just to read wattpad stories. Lastly, everytime I feel sad I suddenly write it on my journal
that became my hobby.

SCHOLASTIC RECORDS
Bacolod City National HS Senior High Science, Technology,
Engineering and
Mathematics
Graduated April 2019
WITH HONORS

Lopez Jaena National HS Junior High Graduated April 2018

WITH HONORS

Pandanon Silos Elementary

School Primary Graduated April 2014

ACHIEVEMENT/ AWARDS/ ACTIVITIES

47
 SENIOR HIGH:
WITH HONORS Grade 12 Graduation S.Y. 2019-2020
WITH HONORS Grade 11 Recognition S.Y. 2019-2020

JUNIOR HIGH:

WITH HONORS Grade 10 Recognition S.Y. 2017-2018

Member Band and Lyre Awardee S.Y. 2017-2018
1st Place Math jingle (LJNHS) S.Y. 2017-2018
WITH HONORS Grade 9 Recognition S.Y. 2016-2017
Champion Streetdance and Massdance S.Y. 2016-2017
(LJNHS)
Participant Sabayang Pagbigkas(LJNHS)S.Y. 2016-2017
Participant Drum and Lyre Contest S.Y. 2016-2017
(STIWNU)
Rank 2 Grade 8-Jade S.Y. 2015-2016
Participant Math Jingle S.Y. 2014-2015
Participant Sabayang Pagbigkas S.Y. 2014-2015
Participant Verse Choir S.Y. 2014-2015
Participant Science Jingle Dance S.Y. 2014-2015

ALFRED SABILLON REVECHE

Prk. Katilingban, Brgy. San Miguel
Murcia, Negros Occidental, Philippines
alfredreveche@gmail.com
09184921895 48
PERSONAL DATA
Age : 19
Date of Birth : February 01, 2001
Religion : Roman Catholic
Height : 5’9
Status : Single
Citizenship : Filipino
Father’s Name : Victorene D. Reveche
Occupation : Unemployed
Mother’s Name : Araceli S. Reveche
Occupation : Housewife

Skills/Talents/Hobbies:
I love to interact with nature. I can sing, though I don’t have a good voice yet not
bad as well. I love to dance like mass dance and pop dance. I do acting but only in
classroom set-up. I consider myself as an artist because I can draw, paint, and my favorite
is calligraphy. Actually, I have my page on Facebook its Fredzone calligraphy watch my
update there if you have time. I love to paint sunset and silhouette. I am a fan of 90’s
Boyband and my favorite is Westlife. I also stan Endless Summer, Now United, and
Boyce Avenue.

SCHOLASTIC RECORDS
Bacolod City National HS Senior High Science, Technology,
Engineering and
Mathematics
Graduated April 2019
WITH HONORS

Lopez Jaena National HS Junior High Graduated April 2018

WITH HONORS

Lopez Jaena Elementary School Primary Graduated April 2014

ACHIEVEMENT/ AWARDS/ ACTIVITIES

SENIOR HIGH:

49
WITH HONORS Grade 12 Graduation S.Y. 2019-2020
WITH HONORS Grade 11 Recognition S.Y. 2019-2020
Member SCIEMATICOS Club S.Y. 2018-2020

JUNIOR HIGH:

WITH HONORS Grade 10 Recognition S.Y. 2017-2018

Member QRT (Quick Response Team)S.Y. 2017-2018
1st Place Math jingle (LJNHS) S.Y. 2017-2018
Participant Streetdance and Massdance S.Y. 2017-2018
(LJNHS)
1st place Tinabu-ay Festival S.Y. 2017-2018
(Streetdance and Massdance)
Participant Slogan Contest (LJNHS) S.Y. 2017-2018
WITH HONORS Grade 9 Recognition S.Y. 2016-2017
Champion Streetdance and Massdance S.Y. 2016-2017
(LJNHS)
Participant Sabayang Pagbigkas(LJNHS)S.Y. 2016-2017
Rank 4 Grade 8-Amethyst S.Y. 2015-2016
Champion Landscaping (LJNHS) S.Y. 2015-2016
Participant Science Quiz Bee S.Y. 2015-2016
Participant Math Quiz Bee S.Y. 2015-2016
Participant Math Jingle S.Y. 2014-2015
Participant Sabayang Pagbigkas S.Y. 2014-2015
Participant Verse Choir S.Y. 2014-2015
Participant Science Jingle Dance S.Y. 2014-2015

50