1.1 House Flies
The house fly or scientifically known as Muscadomestica, is a fly of the Brachycera suborder. It is the most common of all domestic flies, accounting for about 90% of all flies in human habitations, and indeed one of the houseflies feed on faeces, open sores, sputum, and moist decaying organic matter such as spoiled food, eggs and flesh. Houseflies can take in only liquid foods. They spit out saliva on solid foods to predigest it, and then suck it back in. They also regurgitate partly digested matter and pass it again to the abdomen which is then most widely distributed insects, found all over the world; it is considered a pest that can carry serious diseases. In colder climates, houseflies survive only with humans. They have a tendency to aggregate and are difficult to dispel. They are capable of carrying over 100 pathogens such as typhoid, cholera, Salmonella, bacillary dysentery, tuberculosis, anthrax, ophthalmia, and parasitic worms. House flies feed on liquid or semi-liquid substances beside solid material which has been softened by saliva or vomit. Because of their high intake of food, they deposit faeces constantly, one of the factors that make the insect a dangerous carrier of pathogens. Although they are domestic flies, usually confined to the human habitations, they can fly for several miles from the breeding place. They are active only in daytime and rest at night.
1.2 Ozone Layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone (O3). This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is damaging to life on Earth. It is mainly located in the lower portion of the stratosphere from approximately 13 to 40 kilometres (8.1 to 25 mi) above Earth, though the thickness varies seasonally and geographically. Ozone in the Earth's stratosphere is created by ultraviolet light striking oxygen molecules containing two oxygenatoms (O2), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines with unbroken O2 to create ozone, O3. The ozone molecule is also unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into a molecule of O2 and an atom of atomic oxygen, a continuing process called the ozone-oxygen cycle, thus creating an ozone layer in the stratosphere, the region from about 10 to 50 kilometres (33,000 to 160,000 ft) above Earth's surface. About 90% of the ozone in our atmosphere is contained in the stratosphere. Ozone concentrations are greatest between about 20 and 40 kilometres (12 and 25 mi), where they range from about 2 to 8 parts per million. If all of the ozone were compressed to the pressure of the air at sea level, it would be only a few millimeters thick.
Diagram 1.0: Formation of atmosphere
1.3 Ozone Depletion
The ozone layer can be depleted by free radical catalysts, including nitric oxide (NO), nitrous oxide (N2O), hydroxyl (OH), atomic chlorine (Cl), and atomic bromine (Br). While there are natural sources for all of these species, the concentrations of chlorine and bromine have increased markedly in recent years due to the release of large quantities of man-made organohalogen compounds, especially chlorofluorocarbons (CFCs) and bromofluorocarbons These highly stable compounds are capable of surviving the rise to the stratosphere, where Cl and Br radicals are liberated by the action of ultraviolet light. Each radical is then free to initiate and catalyze a chain reaction capable of breaking down over 100,000 ozone molecules. The breakdown of ozone in the stratosphere results in the ozone molecules being unable to absorb ultraviolet radiation. Consequently, unabsorbed and dangerous ultraviolet-B radiation is able to reach the Earth’s surface. Ozone levels, over the northern hemisphere, have been dropping by 4% per decade. Over approximately 5% of the Earth's surface, around the north and south poles, much larger (but seasonal) declines have been seen; these are the ozone holes.In 2009, nitrous oxide (N2O) was the largest ozone-depleting substance emitted through human activities.
1.4 Chlorofluorocarbon
A chlorofluorocarbon (CFC) is an organic compound that contains carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. A common subclass is thehydrochlorofluorocarbons (HCFCs), which contain hydrogen, as well. They are also commonly known by the DuPont trade name Freon. The most common representative isdichlorodifluoromethane (R-12 or Freon-12). Many CFCs have been widely used as refrigerants, propellants (in aerosol applications), and solvents. The manufacture of such compounds is being phased out by the Montreal Protocol because they contribute to ozone depletion. However, the atmospheric impacts of CFCs are not limited to its role as an active ozone reducer. This anthropogenic compound is also a greenhouse gas, with a much higher potential to enhance the greenhouse effect than CO2.Infrared bands trap heat from escaping earth's atmosphere. In the case of CFCs, the strongest of these bands are located at the spectral region - referred to as an atmospheric window due to the relative transparency of the atmosphere within this region The strength of CFC bands and the unique susceptibility of the atmosphere, at which the compound absorbs and emits radiation, are two factors that contribute to CFC's "super" greenhouse effect. Another such factor is the low concentration of the compound. Because CO2 is close to saturation with high concentrations, it takes more of the substance to enhance the greenhouse effect. Conversely, the low concentration of CFCs allow their effects to increase linearly with mass.
1.5 Pesticides
A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical substance, biological agent (such as a virus or bacterium), antimicrobial, disinfectant or device used against any pest. Pests include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, spread disease or are a vector for disease or cause a nuisance. Although there are benefits to the use of pesticides, there are also drawbacks, such as potential toxicity to humans and other animals.
1.6 Biopesticides
Biopesticides are naturally occurring substances (biochemical pesticides) that control pests, microorganisms that control pests (microbial pesticides), and pesticidal substances produced by plants containing added genetic material, plant-incorporated protectants. Biopesticides are biochemical pesticides that are naturally occurring substances that control pests by nontoxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pests. For example, a plant in the presence of chitosan will naturally induce systemic resistance (ISR) to allow the plant to defend itself against disease, pathogens and pests. Examples of biopesticides including 2,6 Octadien-3-ol, 3,7-dimethyl-, Cyclohexanone, 5-methyl-2-(1-methylethyl)-(2R-cis)- and Aristolene Aristol-9-ene.
1.7 Pelargonium radula
Pelargonium radula is originally Malaysian’s plant. It is small-green plants with height about 25 centimetres which produce a rather peculiar smell. Our ancestors call it as “pokok halau nyamuk” as it was used as mosquitoes repellent. Its general name is geranium but Malaysian call it as jeremin. It can live Malaysia’s climate but cannot directly exposed towards sunlight. In Malaysia, the plant is widely planted in Cameron highland and can be easily found at nursery nationwide.
Diagram 2.0: Pelargonium Radula
1.8.0 Major Biopesticide Chemical Compounds found in Pelargonium radula
1.8.1 3,7-dimethyl-1,6-octadien-3-ol
3,7-dimethyl-1,6-octadien-3-ol or also known as Linalool is found naturally in a variety of plants, flowers and spices. As a pesticide, Linalool is intended for use indoors to control pests (fleas and ticks) on pets and the spaces they inhabit by affecting the insect’s nervous system. Linalool is also used as an outdoor mosquito inhibitor. Because of its flavorful and fragrant properties, Linalool has non-pesticide uses and it is added to processed food and beverages, perfumes, cosmetics and soaps as well as to household detergents and waxes. The Food and Drug Administration considers Linalool to be generally recognized as safe (GRAS) as a synthetic flavoring substance and adjuvant in food for human consumption and as an ingredient in animal drugs, feeds and related products.
Diagram 3.0 Chemical structure of 3,7-dimethyl-1,6-octadien-3-ol
| Diagram 4.0 Chemical structure of 2,6 Octadien-3-ol, 3,7-dimethyl- |
2,6 octadien-1-ol,3,7-dimethyl- also known as geraniol. Geraniol is a monoterpenoid C-10 (branched) alcohol found widely as a chief constituent in essential oils including ilang-ilang oil, palmarosa oil, geranium oil, orange flower oil, lemongrass oil, hops oil, and lavender oil. It is a clear to pale-yellow liquid; boiling point 230 C; insoluble in water; soluble in alcohol, ether and most common organic solvents.Geraniol is a pheromone of certain species of bees, being secreted by the scent glands of worker bees to signal the location of nectar-bearing flowers and the entrances to their hives. Geraniol also find an application as an insect repellents.
1.9 Flies Fly Away Year I
‘Flies Fly Away’ is the idea to produce pesticide against flies using Pelargonium radula and contributes to the greener world.
In the previous year, Pelargonium radula, a great potential Malaysian plant was extracted by using hydrodistillation process. Three formulation of extracted oil prepared were 1% , 3%, and 5% by adding distilled water and glycerol in the right proportional.
An experiment was set up to investigate the differences of concentration of extraction oil towards repellent activity against flies and our hypothesis was that the higher the concentration of extraction oil, the more repellent activity against flies. However, our hypothesis could not be accepted as 3% concentration of extracted oil showed more repellent activity against flies compared to 5% concentration of extracted oil.
As the concentration increase the pheromone, a plant hormone biochemical compound which attracts the insects also increase. As the result, 5% concentration of extracted oil showed more attraction activity of flies compared to repellent activity against flies.
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