WO2020106136A1

WO2020106136A1 - A device and a process for inhibiting growth and development of mosquito larvae

Info

Publication number: WO2020106136A1
Application number: PCT/MY2019/050065
Authority: WO
Inventors: Chu Peng PONG
Original assignee: Pong Chu Peng
Priority date: 2018-11-19
Filing date: 2019-09-24
Publication date: 2020-05-28

Abstract

The present invention relates to a device (100) for inhibiting growth and development of mosquito larvae and a process thereof. The device (100) comprises a perforated housing (E) with a passage therebetween having a top opening and a bottom opening with end caps at each of the openings; an inner layer (H) within the housing (E) comprising at least one chamber. The device (100) of the present invention further comprises a first fastening (D1) for holding the inner layer (H) of the housing; and a second fastening means (D2) for holding the holding means of the plurality of threads within the inner layer chamber of the housing.

Description

A DEVICE AND A PROCESS FOR INHIBITING GROWTH AND DEVELOPMENT OF

MOSQUITO LARVAE

FIELD OF INVENTION

The present invention relates to a device and a process for inhibiting the growth and development of mosquito larvae through a simple, effective and non-toxic mechanism. In particular, the device of the present invention comprises copper particles coated with salt compound whereby the copper particles inhibit growth and development of mosquito larvae upon contact of the copper particles with water.

BACKGROUND OF ART

Mosquitos require water for breeding and only a small volume of water is required for mosquito to lay their eggs. The breeding areas for mosquitos are stagnant water. There are four stages of development of mosquito which includes egg, larva, pupa and adult and only larval and pupae stages are spent in water. Various devices and methods for trapping and killing mosquitos from eggs larval stages have been invented to control and reduce mosquito population that causes mosquito borne diseases.

Controlling and extermination of mosquitos population at eggs and larval stage without utilizing poisonous chemical and hazardous method is desirable to prevent transformation of mosquitos into stronger species.

European Patent Publication No. EP 1645188 A1 (hereinafter referred to as ERΊ88 A1 Publication) entitled“Device against the development of larvae in water” having a filing date of 29 September 2005 (Applicant: Placucci, Alessandro) discloses a device for inhibiting development of larvae in water. The ERΊ88 A1 Publication provides that the device comprises metallic copper packaged in containers whereby the said containers can be opened, frangible, water soluble or water permeable. The device of ERΊ88 A1 Publication containing predetermined amount of metallic copper is destined to be immerged into a predetermined amount of water for preventing the development of larvae. The ERΊ88 A1 Publication provides the device further comprises an oxidant material to increase copper oxide formation in free or poor oxygen water in facilitate copper oxidation.

Japanese Patent Publication No. JP 2012039992 A (hereinafter referred to as JP’992 A Publication) entitled“Container for exterminating mosquito larvae” having a filing date of 23 August 2010 (Applicant: Matano Shinichi) discloses a container for exterminating mosquito larvae by utilizing copper ions. The JP’992 A Publication discloses the container comprises a protruding hollow tube having holes in a lower part of a reverse conical shaped concave guide cylinder, a copper plate or a copper wire wrapped around a the hollow tube for generating the copper ions in water. The J P’992 A Publication provides that the hollow tube is stored in a water storage container having a convex guiding part formed at a bottom part of the container. The JP’992 A Publication further provides a method for inducing mosquito larvae hatched from eggs by allowing the larvae to settle along an inclined surface of the container thereafter passing through the hollow tube having copper plate or a copper wire wrapped around the hollow tube to inhibit the growth of the mosquito larvae.

Japanese Patent Publication No. JP 2017218406 A (hereinafter referred to as JP’406 A Publication) entitled“Mosquito larvae generation inhibitor and mosquito larvae generation inhibition tool” having a filing date of 7 June 2016 (Applicant: Akimitsu, Y. and Masami, O) discloses a mosquito larvae generation inhibitor made from copper or copper alloy in the form of activated copper which capable of eluting a large amount of copper ions over long period of time to enhance the inhibition effects of mosquito larvae generation. The JP’406 A Publication discloses the mosquito larvae generation inhibition tool comprises a hollow short pipe made of used copper pipe to provide large surface area for copper ion elution. The JP’406 A Publication further discloses the mosquito larvae generation inhibitor may be packed in a nonwoven fabric bag whereby the non-woven fabric bag is configured to be immersed in water during use.

As outlined above, various devices and processes are currently available to control and reduce a population of mosquitos from eggs and larvae stages. However, it is desirable to have a device and process utilizing copper particles that effectively kills larvae within a short period of time through a simple, cost effective; and non-toxic mechanism.

SUMMARY OF INVENTION

The present invention consist of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

One aspect of the present invention provides a device (100) for inhibiting growth and development of mosquito larvae, the device comprising a perforated housing (E) with a passage therebetween having a top opening and a bottom opening with end caps at each of the openings; an inner layer (H) within the housing (E) comprising at least one chamber having a top opening (I) and a bottom opening (J); and a plurality of threads (L) held by holding means within the chamber of the inner layer of the housing. The present invention further provides that, the plurality of threads (L) held by the holding means are integrated with processed copper particles which inhibits growth and development of mosquito larvae upon contact of the copper particles with water. The device further comprises fastening means with a first fastening means (D1 ) for holding the inner layer (H) of the housing; and a second fastening means (D2) for holding the holding means of the plurality of threads within the inner layer of the chamber of the housing.

Another aspect of the present invention provides that the plurality of threads (L) held by holding means are integrated with copper particles; said copper particles are in form of thin paper, wire, rod, powder or minute form.

Preferably the copper particles are coated with salt preferably sulphate, nitrate or chloride.

A further aspect of the present invention provides that the inner layer (H) includes both perforated and n on-perforated layer.

Yet another aspect of the present invention provides that the first fastening means (D1 ) includes screws and nuts or pins affixed to bore holes (D4) of the housing (E) and the inner layer (H), provides the bore holes of the housing (E) which are parallel to bore holes of the perforated inner layer (H).

Further, the present invention provides that the second fastening means (D2) includes screw and nuts or pins affixed to bore holes of the inner layer (H). Another aspect of the present invention provides that the plurality of threads includes packages in a form of a sack formed from porous paper or cloth or teabags having copper particles which are directly in contact with water.

A further aspect of the present invention provides that process (500) for inhibiting growth and development of mosquito larvae, the process comprises steps of preparing (502) copper particles from copper filiform or fragments; and releasing (504) copper particles into water by means of placing a device filled with copper particles coated with salt. The present invention further provides that the copper particles is made in form of thin paper, wire, rod, powder or minute form is integrated with a plurality of threads.

Yet another aspect of the present invention provides that preparing (504) copper particles from copper filiform or fragments further comprising steps of breaking (504A) a copper filiform or fragments into copper atom; re-constructing (504B) copper atom into copper particles of at least 2 to 3 mm by electrolysis; coating (504C) the copper particles with a layer of salt by treating the copper particles with acid; drying (504D) the layer of salt coating the copper particles; and packing (504E) the copper particles covered with the layer of salt in a vacuum pack.

A further aspect of the present invention provides that coating (504C) the copper particles with a layer of salt by treating the copper particles with acid includes sulphuric acid, nitric acid or hydrochloric acid for producing a layer of salt of sulphate, nitrate or chloride.

Another aspect of the present invention provides that reconstructing (504B) copper atom into copper particles by electrolysis further comprising steps of rolling copper wire or copper materials and placing the rolled copper wire in a glass container on left side of the container to act as a positive electrode; inserting a copper rod into the glass container and placing the copper rod on the right side of the container to act as a negative electrode; filling the container with diluted acid by adding at least 20% of water to a concentrated acid; applying 6/5 volts current to the positive electrode and 5/6 volts current to the negative electrode; loosening copper atom from the rolled copper wire, the said copper atom is deposited onto the negative electrode provided a layer of salt is formed around the deposited copper atom; collecting the deposited copper atom from the negative electrode; and drying the deposited copper atom.

The present invention consists of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

To further clarify various aspects of some embodiments of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the accompanying drawings.

Figure 1.0A illustrates a perspective view of a device according to one embodiment of the present invention. Figure 1. OB illustrates a front view of a housing of the device of according to one embodiment of the present invention.

Figure 1.0C illustrates a side view of a housing of the device according to one embodiment of the present invention.

Figure 1.0D illustrates a top view of the device of according to one embodiment of the present invention.

Figure 1.0E illustrates a bottom view of the device according to one embodiment of the present invention.

Figure 2.0 illustrates a cross-sectional view of the device according to one embodiment of the present invention. Figure 3.0A illustrates a perspective view of an inner layer of the device according to one embodiment of the present invention.

Figure 3.0B illustrates a front view of the inner layer of the device according to one embodiment of the present invention.

Figure 3.0C illustrates a side view of the inner layer of the device according to one embodiment of the present invention.

Figure 3.0D illustrates a top view of the inner layer of the device according to one embodiment of the present invention.

Figure 3.0E illustrates a bottom view of the inner layer of the device according to one embodiment of the present invention. Figure 4.0 illustrates a perspective view of a plurality of threads held by holding means according to one embodiment of the present invention.

Figure 5.0 is a flow chart of the general process for inhibiting the growth and development of mosquito larvae according to one embodiment of the present invention.

Figure 5.1 is a flowchart of the steps involved for preparing copper particles from copper filiform or fragments

Figure 6.0 illustrates the device submerged in the 250 ml distilled water in a disposable plastic cup (9 cm height; 8 cm diameter) containing 25 live late third and early fourth A. albopictus larvae.

Figure 7.0 illustrates bioassay against A. albopictus larvae. Figure 8.0 illustrates an experimental design used in mosquito larvicidal testing of the present invention.

Figure 9.0 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 1 ) as compared to the Control in the Experiment 1 (controls without the device) under the laboratory condition of 22.73±2.2°C and 70% relative humidity at the Institute of Medical Molecular Biotechnology, Faculty of Medicine, UiTM Sungai Buloh Campus. The bars indicated standard deviations at each reading point.

Figure 9.1 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 2) as compared to the Control in the Experiment 1 (controls without the devices) under the laboratory condition of 22.73±2.2°C and 70% relative humidity at the Institute of Medical Molecular Biotechnology, Faculty of Medicine, UiTM Sungai Buloh Campus. The bars indicated standard deviations at each reading point.

Figure 9.2 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 3) as compared to the Control in the Experiment 1 (controls without devices) under the laboratory condition of 22.73±2.27°C and 70% relative humidity at the Institute of Medical Molecular Biotechnology, Faculty of Medicine, UiTM Sungai Buloh Campus. The bars indicated standard deviations at each reading point.

Figure 9.3 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 1 ) as compared to the Control in the Experiment 2 (controls with devices without copper particles) under the laboratory condition of

22.73±2.27°C and 70% relative humidity at the Institute of Medical Molecular Biotechnology, Faculty of Medicine, UiTM Sungai Buloh Campus. The bars indicated standard deviations at each reading point.

Figure 9.4 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 2) as compared to the Control in the Experiment 2 (controls with the device without copper particles) under the laboratory condition of

22.73±2.27°C and 70% relative humidity at the Institute of Medical Molecular Biotechnology, Faculty of Medicine, UiTM Sungai Buloh Campus. The bars indicated standard deviations at each reading point

Figure 9.5 illustrates the percentage of A. albopictus larval mortality following exposure to 1 gm of copper particles in the devices (Trial 3) as compared to the Control in the Experiment 2 (controls with the device without copper particles) under the laboratory condition of

Figure 10.0 illustrates a statistical output of Wilcoxon Signed Rank Test on the mortality of A. albopictus larvae between the Control and Treatment groups using pooled data from both Experiments and all Trials and Replicates.

Figure 1 1 .0 illustrates a bar chart showing the mean mortality of A. albopictus larvae between Treatment and Control. Error bars indicated 95% Confidence Interval (Cl).

Figure 12.0 illustrates a profile plot of the estimated marginal means of larval mortality of A. albopictus based on the univariate model according to Day and Group (Treatment and Control). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 1 .OA -1 0E illustrate a perspective view, front view, top view and bottom view of a device according to one embodiment of the present invention. As illustrated in Figure 1 .0, the device (100) utilizes the copper particles to inhibit growth and development of mosquito larvae comprising a housing (E) with a passage therebetween having a top opening and a bottom opening with end caps (F, X) at each opening. The end caps (F, X) includes an upper cap (F) affixed to the opening of the housing and a bottom cap (X) affixed to the bottom opening of the housing. The end caps (F, X) is configured to trap the air to enable the device to float in the water. It is provided herein that the end caps (F, X) are made of material capable of floating in water. The present invention further provides that the housing (E) is a perforated (G) housing with preferably at least 3 mm diameter of perforation which allows water to flow into the device (100) freely and thereafter pushing air into the end caps and preventing the air in the end caps (F, X) from escaping to ensure that the device (100) floats in the water. It is provided herein that the housing can be of any shape or size and it is preferably made of polyvinyl chloride (PVC) type material or any other material known in the state of the art. Preferably, the device of the present invention is of a length of at least 6 cm and of a width of at least 2.5 cm.

Reference is now made to Figure 2.0 which illustrates a cross-sectional view of the device according to one embodiment of the present invention. As illustrated in Figure 2.0, the device further comprises an inner layer (FI) positioned within the housing (E). It is provided herein that the inner layer having a dimension less than the housing (E) and is to be positioned within the housing. The inner layer (FI) of the present invention includes both perforated and non -perforated layer. The present invention provides that the inner layer is held within the housing (E) by a first fastening means (D1 ). The first fastening means (D1 ) includes screws and nuts or pins affixed to bore holes (D4) of the housing (E) and the inner layer (FI). It is provided herein that the bore holes (D4) of the housing (E) are parallel to bore holes of the perforated inner layer (FI). The present invention further includes a plurality of stoppers (D3) to hold the inner layer (FI) in place within the housing (E). Reference is now made to Figures 3.0A-3.0E which illustrate a perspective view, front view, top view and bottom view of the inner layer of the device according to one embodiment of the present invention. As illustrated in Figures 3.0A-3.0E, the inner layer (FI) of the present invention comprises a top opening (I), a bottom opening (J) and at least one chamber to hold a plurality of threads by means of holding means. The present invention further provides that the top opening (I) and the bottom opening (J) may include end caps at each of the openings. The device of the present invention further comprises a second fastening means (D2) which includes screws and nuts or pins affixed to bore holes of the inner layer (FI) to hold the holding means of the plurality of threads within the inner layer chamber of the housing.

Figure 4.0 illustrates a perspective view of a plurality of threads held by holding means according to one embodiment of the present invention. As illustrated in Figure 4.0, the plurality of threads (L) are integrated with copper particles which inhibits growth and development of mosquito larvae upon contact of the copper particles with water. The copper particles of the plurality of threads may include cooper made in the form of thin paper, wire, rod, powdered form. Preferably the copper particles of the present invention are coated with sulphate, nitrate or chloride.

In another embodiment of the present invention, the plurality of threads may be substituted in packages in a form of a sack formed from porous paper or cloth or teabags having copper particles. The packages are placed directly in contact with water to inhibit growth and development of mosquito larvae.

Reference is now made to Figure 5.0 which illustrates a flow chart of the general process for inhibiting the growth and development of mosquito larvae involves according to one embodiment of the present invention. As illustrated in Figure 5.0, the process (500) for inhibiting growth and development of mosquito larvae comprising steps of preparing (502) copper particles from copper filiform or fragments whereby the copper particles in form of thin paper, wire, rod, powder or minute form is integrated with a plurality of threads. Thereafter the copper particles are released (504) into water by means of placing a device filled with copper particles coated with salt. Upon in contact with water, the layer of salt melts slowly and releases copper atoms into water thereafter supressing the development of eggs and larvae to become pupae and adult mosquitos. The layer of salt functions as coating agent and activator to the copper particles. The dissolvability of copper ions in water depends on surface area of the copper which is in contact with water. The present invention provides that, in stagnant water, the effectivity of the copper particle to inhibit growth and development of mosquito larvae can last for at least between 3 to 6 months.

Figure 5.1 illustrates the steps involved for preparing copper particles from copper filiform or fragments. As illustrated in Figure 5.1 , the process for preparing copper particles for use to inhibit growth and development of mosquito larvae further comprising steps of first breaking (502A) a copper filiform or fragments into copper atom to increase the surface area of the copper atoms by a few hundred times as compared to the original copper filiform or fragments to increase dissolvability rate of the copper atom. Next, the copper atom is re-constructed (502B) into copper particles of at least 2 to 3 mm by means of electrolysis and thereafter the copper particles are coated (502C) with a layer of salt. For example coating of the cooper particle with sulphate would require sulphuric acid to be utilized to treat the copper particles. If the copper particles are coated with nitrate, nitric acid is utilized and if the copper particles are coated with chloride, hydrochloric acid is utilized to treat the copper particles. Upon coating the copper particles with a layer of salt, the copper coated with the layer of salt is dried (502D) by utilizing a dryer or the layer of coated salt is left to be dried naturally. Upon drying the layer of coated salt on the copper particles, the copper particles coated with the layer of salt is packed (502E) in a vacuum pack to maintain the effectiveness of the copper particles.

The present invention further provides the general methodology for re-constructing copper particles from copper atom by electrolysis. The process comprises steps of first rolling copper wire or copper materials and placing the rolled copper wire in a glass container on left side of the container to act as a positive electrode (Anode). Next, a copper rod is inserted into the glass container and is placed on the right side to act as a negative electrode (Cathode). It is provided herein that the container is filled with dilute acid whereby acid is added to at least 20% of water. The acid includes sulphuric acid, nitric acid or hydrochloric acid. The dilute acid will dissociate the water into hydrogen ions to facilitate electric conductivity.

Thereafter, 6/5 volts current is applied to positive electrode and 5/6 volts current is applied to the negative electrode to complete the circuit. Upon applying the current to both the positive electrode and the negative electrode, the electrons at the anode will lose the copper atom and the loosen copper atom will be attracted to the cathode and will be deposited to the cathode. The cathode will act as copper atom collector. After 20 - 30 minutes of the process, the deposited copper atom will be harvested.

Copper salt formed during electrolysis depends on the type of acid used during the process. For example copper sulphate, copper nitrate and copper chloride is formed by utilizing sulphuric acid, nitric acid or hydrochloric acid respectively. The salt will be formed around the copper atom deposited on the cathode. Upon drying of the copper atom, the salt formed around the copper atom will form a layer of salt coating around the atom.

The present invention provides that copper coated with salt will facilitate dissociation of copper ion from the copper particles and the salt coating prevents copper from being oxidized. The oxidized copper will reduce the effectivity of the copper particles in such a way that the oxidized copper prevents copper ions from escaping and dissociate upon in contact with water. The present invention provides that, the device of the present invention is capable of killing mosquito larvae at late third instar and early fourth instar within at least four days of treatment.

Another embodiment provides that the processed copper particles may be implemented by engaging nano-technology to yield very small copper particles. A further embodiment provides that the copper particles may be sprayed onto the filament housing in the device or may be sprayed on any materials of origin of the mosquito larvae. Spraying of the copper particles is performed by means of a drone or a blower gun whereby the copper particles are incorporated within the drone or the blower gun. The means of spraying the copper particles through the drone or blower gun enable the copper particles to reach out to far fledge unreachable areas of mosquito breeding grounds such as tyres in dumping grounds.

The effectiveness of the device of the present invention to inhibit development of larvae is confirmed through preliminary investigation on the larval susceptibility of Aedes albopictus (Skuse, 1984) (Diptera: Culicidae) to Copper in the laboratory setting.

An experimental data for mosquito larvicidal testing is provided herewith based on preliminary investigation on the larval susceptibility of Aedes albopictus (Skuse, 1984) (Diptera: Culicidae) to Copper in the laboratory setting.

1. Mosquito strain

The field strains of A. albopictus larvae were collected by using 5-litre water pails placed on the ground within the vicinity of Universiti Teknologi MARA (UiTM), Sungai Buloh Campus which is adjacent to the Institute of Medical Molecular Biotechnology (IMMB) (3°13’18.168” N 101°35’36.614”). Only late third or early fourth instar mosquito larvae were picked up using pipette and transferred to the plastic cups for testing. Several mosquito larvae were randomly preserved in 70% ethanol for species identification. Light microscopic identification was conducted using a stereomicroscope (Olympus SZ51 , Japan) under a range of magnifications (0.8x - 4.0x) in the laboratory. Morphological characteristics of A. albopictus larvae were confirmed using the taxonomical key of Rueda (2004).

2. Device

For larval bioassay testing, the device (~6 cm x ~2.5 cm) containing 1 gm of copper particles was used. When the devices were placed in a disposable plastic cups (9cm height; 8 cm diameter), it did not float, but submerged under the waterline. Figure 6.0 illustrates the device submerged in the 250 ml distilled water in a disposable plastic cup (9 cm height; 8 cm diameter) containing 25 live late third and early fourth A. albopictus larvae.

3. Bioassay against mosquito larvae

Larval bioassay procedures recommended by WHO (1981 ) were referred and used. Bioassay was conducted in disposable plastic cups. Twenty-five (n= 25) late third or early fourth instar larvae were exposed to the floats in 250 ml distilled water. The plastic cups were held at room temperature of approximately 22.73±2.2°C and 70% relative humidity in the entomological laboratory at IMMB, UiTM Sungai Buloh Campus. All plastic cups were covered by a sheet of breathable cloth to prevent environmental contamination or insect colonization from the surroundings. Figure 7.0 illustrates bioassay against A. albooictus larvae setting. As illustrated in figure 7.0, the top row of three plastic cups served as the control group while the three plastic cups at the bottom row served as the treatment group. C denotes Control; T denotes Treatment. C1 - C3 were the replicates of the Control group while T1 - T3 were the replicates of the Treatment group (device filled with copper particles).

4. Experiment design for the Control group

For the first experiment, the control (untreated) consisted of 250 ml distilled water and 25 mosquito larvae without the float. For the second experiment, the control (untreated) consisted of the float casing without the copper particles. Three replicates were conducted at one time (known as single trial), and the trial was triplicated (total was three trials). Figure 8.0 illustrates an experimental design used in mosquito larvicidal testing of the present invention. As illustrated in Figure 8.0 Three trials were conducted in each experiment, and each trial was replicated thrice. In Experiment 1 , the Control consisted of 250 ml distilled water and 25 mosquito larvae without the float while in the Experiment 2, the Control consisted of the float casing without copper and 25 mosquito larvae. The larval mortality was recorded daily in the morning (~10 am) until the mortality percentage achieved 100%. The duration of the experiment was set for nine days.

5. Data analysis

The test results obtained from the bioassay were pooled and analysed using SPSS version 24 (IBM) and Microsoft Excel (2016). Statistical tests were employed to determine significant difference. P value < 0.05 is considered statistically significant.

Figures 9.0-9.2 show the percentage of mortality of A. albopictus after exposure to the device containing 1 gm of copper particles in the Experiment 1 (controls without floats) while Figures 9.3-9.5 show the percentage of mortality of A. albopictus after exposure to the device containing 1 gm of copper in the Experiment 2 (controls with float casing without containing copper). In general, the 90% mortality was achieved the earliest by Day 5 after exposure to the copper in the floats. Note that Day 1 denoted the first day of device placement in the disposable plastic cups and exposed to the mosquito larvae.

Statistic showed the overall mean for killed larvae in the Treatment group was 17.17±8.64 (out of 25) and Control group was 5.04±4.8 (out of 25) (see Figure 13). The dataset was not normally distributed according to both Kolmogorov-Smirnov and Shapiro-Wilk tests (p < 0.01 ). Hence, non-parametric tests such as Wilcoxon and Kruskal-Wallis test were employed. There was no replicate effect in both Treatment (p = 0.392) and Control (p = 0.749) groups. Therefore, the data was pooled in the subsequent statistical analyses. However, both Experiments and Trials demonstrated significant effect in the mortality of mosquito larvae in both Treatment and Control groups (p < 0.001 ).

Kruskal-Wallis test demonstrated a significant difference between Days, Control and Treatment with p < 0.001 , indicated the mortality of mosquito larvae was significantly different over time. The correlation between Day, Control and Treatment were also correlated significantly (p< 0.001 ) using Spearman test. A strong and positive relationship was obtained for Control and Treatment with correlation coefficient 0.699 and 0.833, respectively. Statistical comparison using Wilcoxon test between Treatment and Day showed a Significant difference (p < 0.001 ) whereas comparison between Control and Day did not show significant difference (p = 0.616). Most importantly, a significant difference was detected in the mortality of A. albopictus larvae between Control and Treatment groups (p < 0.001 , Z = -13.158) (Figure 10.0) where larval mortality was significantly higher in the Treatment group (Figure 1 1.00).

Univariate analysis demonstrated Significant differences (p < 0.001 ) between Day, Group (Control and Treatment), with an interaction between Day and Group. Figure 12.0 shows an estimated marginal means of A. albopictus larval mortality according to Day and Group (Treatment and Control).

This preliminary investigation on copper particles susceptibility on mosquito larvae was conducted using the late third instar and early fourth instar of field strain A. albopictus collected within the vicinity of UiTM Sungai Buloh Campus. A total of two experiments, six trials, and 18 replicates have been carried out under the laboratory condition (22.73±2.27°C and 70% relative humidity) in UiTM Sungai Buloh Campus.

The main ingredient, 1 gm of copper, installed within the devices was tested against the larvae of A. albopictus. Statistical comparisons between the Treatment (mosquito larvae exposed to the device with copper particles) and Control (mosquito larvae did not expose to copper particles) demonstrated a significant difference where the Treatment group achieved much higher mortality percentage (mean mortality for Treatment was 17.17±8.64 (out of 25) compared to the Control (mean mortality 5.04±4.8 (out of 25). Replicates did not have significant effect on the larval mortality while other factors such as Experiment, Trial, Day and Group (Control and Treatment) did. Furthermore, positive and significant correlations were detected between Day and Groups (Control and Treatment). It is also known that copper was effective in killing many insects including mosquito larvae (Reza et al. 2014; Timmermans et al. 1992; Doty, 1905).

It is noteworthy to mention that the mosquito larval mortality rate is highly dependent on multiple biotic and abiotic factors including mosquito species and strain, developmental stage, larval health status, pre-exposure diet, larval density, water temperature and pH, the type and amount of testing ingredient used (in this case, the copper). Based on the data and statistical analyses obtained from this preliminary investigation, it was suggested that the device containing 1 gm of copper particles in the present invention was able to serve as a larvicidal device for field strain A. albopictus larvae of late third and early fourth instars collected from Sungai Buloh, Selangor, Malaysia, where 90% of larval mortality was achieved the earliest by Day 5 post-exposure to the copper-containing floats.

The present invention further affirms that the use of processed copper particles to inhibit growth and development of mosquito larvae in water is proven safe, non-toxic and consumable as the pH level of water together with the contents of iron, manganese, aluminium and copper meet the requirements of the Ministry of Health Malaysia. In support of the above, a clinical test has been conducted by a private laboratory (i.e. Taliworks Analytical Laboratory Sdn Bhd) whereby two samples of treated water with addition of processed copper particles are tested based on Standard Methods for the Examination of Water and WasteWater (2005) 21 ^st Edition, APHA, AWWA, WEF to determine the physical and chemical content of water. The results of the clinical test are shown in Tables 1.0 and 1 .1 . Based on the results in Tables 1.0 and 1.1 , it can be concluded that the water with added processed copper particles used to inhibit growth and development of mosquito larvae in water meet the requirements of the Ministry of Health Malaysia. Table 1.0: Physical and chemical analysis of Treated Water Sample (pH,

Turbidity, Color, Chlorine, Iron, Manganese and Aluminium)

Table 1.1 : Physical and chemical analysis of Treated Water Sample (pH and Copper content)

In conclusion, the distinctiveness of the present invention lies in a device having a copper particles coated with salt filled which inhibits growth and development of mosquito larvae upon contact of the copper particles with water.

Unless the context requires otherwise or specifically stated to the contrary, integers, steps or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.

Throughout this specification, unless the context requires otherwise, the word“comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers, but not the exclusion of any other step or element or integer or group of steps, elements or integers. Thus, in the context of this specification, the term“comprising” is used in an inclusive sense and thus should be understood as meaning“including principally, but not necessarily solely”.

Claims

1. A device (100) for inhibiting growth and development of mosquito larvae, the device comprising:

a perforated housing (E) with a passage therebetween having a top opening and a bottom opening with end caps at each of the openings; an inner layer (H) within the housing (E) comprising at least one chamber having:

a top opening (I) and a bottom opening (J);

a plurality of threads (L) held by holding means within the chamber of the inner layer of the housing; and

fastening means with a first fastening means (D1 ) for holding the inner layer (H) of the housing; and a second fastening means (D2) for holding the holding means of the plurality of threads within the inner layer of the chamber of the housing;

characterised in that

the plurality of threads (L) held by the holding means are integrated with processed copper particles which inhibits growth and development of mosquito larvae upon contact of the copper particles with water.

2. The device (100) according to claim 1 , wherein the plurality of threads (L) held by holding means are integrated with copper particles; said copper particles are in form of thin paper, wire, rod, powder or minute form.

3. The device (100) according to claim 1 , wherein the copper particles are coated with salt preferably sulphate, nitrate or chloride.

4. The device (100) according to claim 1 , wherein the inner layer (H) includes both perforated and no n-perf orated layer.

5. The device (100) according to claim 1 , wherein the first fastening means (D1 ) includes screws and nuts or pins affixed to bore holes (D4) of the housing (E) and the inner layer (H), provides the bore holes of the housing (E) which are parallel to bore holes of the perforated inner layer (H).

6. The device (100) according to claim 1 , wherein the second fastening means (D2) includes screw and nuts or pins affixed to bore holes of the inner layer (H).

7. The device (100) according to claim 1 wherein the plurality of threads includes packages in a form of a sack formed from porous paper or cloth or teabags having copper particles which are directly in contact with water.

8. A process (500) for inhibiting growth and development of mosquito larvae, the process comprises steps of:

preparing (502) copper particles from copper filiform or fragments; and releasing (504) copper particles into water by means of placing a device filled with copper particles coated with salt;

characterized in that

releasing copper particles into water by means of placing a device filled with the copper particles coated with salt, the copper particles are made in form of thin paper, wire, rod, powder or minute form and is integrated with a plurality of threads.

9. The process (500) according to claim 8, wherein preparing (504) copper particles from copper filiform or fragments further comprising steps of:

breaking (504A) a copper filiform or fragments into copper atom; re-constructing (504B) copper atom into copper particles of at least 2 to 3 mm by electrolysis;

coating (504C) the copper particles with a layer of salt by treating the copper particles with acid;

drying (504D) the layer of salt coating the copper particles; and packing (504E) the copper particles covered with the layer of salt in a vacuum pack.

10. The process according to claim 9, wherein coating (504C) the copper particles with a layer of salt by treating the copper particles with acid includes sulphuric acid, nitric acid or hydrochloric acid for producing a layer of salt of sulphate, nitrate or chloride.

1 1 . The process according to claim 9 wherein reconstructing (504B) copper atom into copper particles by electrolysis further comprising steps of:

rolling copper wire or copper materials and placing the rolled copper wire in a glass container on left side of the container to act as a positive electrode;

inserting a copper rod into the glass container and placing the copper rod on the right side of the container to act as a negative electrode; filling the container with diluted acid by adding at least 20% of water to a concentrated acid;

applying 6/5 volts current to the positive electrode and 5/6 volts current to the negative electrode;

loosening copper atom from the rolled copper wire, the said copper atom is deposited onto the negative electrode provided a layer of salt is formed around the deposited copper atom;

collecting the deposited copper atom from the negative electrode; and drying the deposited copper atom.