1.1 INTRODUCTION
Malaria is one of the commonest and major parasitic infections of public health interest in the globe especially in the tropics and sub-tropics. It still remains the principal cause of morbidity and mortality in all sub-saharan countries up to this day. Malaria accounts for 10% - 30% of all hospital admissions, and is responsible for 15% - 25% of all deaths in children under the age of 5 years. Pregnant women are not be exonerated from the risk of malaria infections as the disease is also said to be responsible for a substantial number of miscarriages and underweight births (WHO, 1996; RMB, 2007). Globally, only mosquitoes of the genus Anopheles have been incriminated as the vectors of this life-threatening disease. Therefore the control of malaria invariably implies sustainable control of its vectors.
One of the best control measures is the application of intervention methods. Such intervention methods involve the use of insecticides, larvicides, topical repellents among others, to intercept the vector-host interactions or contact. Cutting off or breaking the link between mosquito vectors and human hosts consequently disrupts the life cycle of malaria parasite. The overall result is the reduction in morbidity and mortality rates following reduced transmission of the disease (Toure, 2002). Beside from the use of insecticide treated nets (ITNS), many other different types of substances, natural and synthetic, have been discovered and adopted to protect human hosts against mosquito bites. These substances keep mosquitoes from biting humans and make human hosts undetectable, or are anti-mosquito cloak that conceal or hide the host from recognition by mosquitoes, as a meal source (Jacobson, 1990; Foster and Duke, 1990; ICMR, 2003). Today citrus essential oils as well as extracts from other plants such as Cedar wood, Citronella, Eucalyptus, Pennyxoyai, Turpentine, Winter green (Sadik, 1973), have been identified as very important natural resource of either pesticides or insecticides (Raguraman and Singh, 1997; Gbolade, 2001), or repellent (Sadik, 1973; Thorsell et al., 1998; Oyedele et al., 2000; Govere et al., 2000; Girgenti and Suss, 2003). They have been used as both topical preparations and combustible products like incense sticks to repel insects such as mosquitoes.
In some places, dried citrus fruit peels are burnt on charcoal fire to repel and/or destroy mosquitoes in homes.The global preference of phytochemicals in malaria vector control may be based on their unique properties which include environmental sustainability, easily biodegradable, readily available and cheap andnon-toxicity to man and his domestic animals (Herrera and Vieto, 1980; Duke, 1992). Repellent and attractant properties of phytochemicals from plants other than citrus plant species have been investigated by various scholars (Tyagi et al., 1994; Ansari and Razdam, 1995; Trigg, 1996; Pathak et al., 2000; Moore et al., 2002).
Mosquitoe insecticides are quick and powerful way to get rid of mosquitoes but unfortunately they are only temporary. The effect usually lasts only as long as the insecticide is present, as soon as it drift away or dries out, the mosquitoes are back. Mosquitoes control officials use insecticides only in combination with other form of mosquito control. The same method should apply to use around the house. Insecticides are not long-term solution. Insecticides are commonly dispersed through a fog or ultralow volume mist. Insecticides are available at most home and garden stores, and it come in hand- held applicator or devices that can be attached to a lawn mower. Example of two popular insecticides are Malathion and Permethrin.
Malathion is an organophosphate often used to treat crops against a wide array of insects. It can be sprayed directly onto vegetation such as bushes where mosquitoes like to rest, or used in a 5% solution to fog in the yard. In small amount used for mosquito control , it poses no threat to humans or wide life. In fact, Malathion is also used to kill headlice.
Permethrin is one of the group of chemicals called Pyrethroids. It is a synthetic form of a natural insecticides found in Chrysanthemus flowers. It usually mixed with oil or water and applied as a mist about 1/100th of a pond per acre. Like Marathion, permethrin kills mosquitoes by disrupting their nervous systems. Not harmful to humans and animals in small quantity, but toxic to fishes and bees.
Both Malathion and permethrin are also available in sprays for use inside the home. The insecticides works for several days when applied to shrubbery or grass, but will breakdown overtime, especially in rain. When released into air through fog or mist. They are usually good for few hours before they become too dissipated to be effective.
1.2. STATEMENT OF THE PROBLEM.
Over the years, mosquitoes pose a great threat to humans' health. So, need arise to develop a lasting solution to the invasion of mosquitoes in our environment. Different methods had been detected to control mosquitoes but there is need to develop a cheap, easy to produce, and long lasting solution.
1.3. OBJECTIVES OF THE STUDY.
The main objectives of the study is the production of mosquito repellant insecticides using plant extracts which will be cheap, effective and readily available for everyone even in rural area.
1.4. RESEARCH QUESTIONS
1. What is an insecticides?
2. What is the effect of plants extract on mosquito?
3. Is mosquito repellant insecticides a lasting solution to mosquito invasion?
1.5. SIGNIFICANCE OF THE STUDY.
Overtime and repeated use of insecticides resistance can occur in mosquito population. Scientists researching the subject believe that the ability of mosquitoes to resist insecticides represent a serious threat to the prevention of diseases such as Malaria, dengue, Chikunginya. This threaten effort to prevent epidermis.
Mosquitoes can be reduced or controlled around our homes naturally through the use of natural or biological means. Predatory fish (Gambusia), Dragonflies, plant repellant, bacteria and even other mosquitoes that are mosquito eaters. Citrosa, Lemon thyme, and Rosemary plants are known to be good insect repellant. Bacillus Thurigiesis Israelensis is a Natural occurring bacteria used as a larvacide in ponds and other areas where mosquitoes are breeding. These are poisonous to mosquito larvae when they feed on it in the water. Mosquito trap are also good method of controlling mosquitoes on our area.Orange peel also known as Cestrum is a wonderful hybrid derived from Cestrum diurnum and Cestrum Nocturnum. Cestrum is a veritable living bouquet of pure orange blossoms that strives well in warm climates. Orange peel is a fragrant orange flower, it need low maintenance and strives in hot weather. Orange peel contains oil known as Limonene oil which has a lethal effect on mosquito and some other insects. Hence, Cestrum can be used as an active ingredient to produce mosquito coil, which when ignited will repel mosquitoes within the limit of the smoke.
1.6. SCOPE OF THE STUDY.
The research focus on the production of mosquito repellant insecticides using plant extracts.
REFERENCES
1. Ansari M. A. and Razdam R. K. 1995. Relative efficacy of various oils in repelling mosquitoes. Indian Journal of malariology, 32, 104.
2. Duke J. A. 1992. Handbook of biologically active phytochemicals and their activities. CRK press Boca Eaton, Florida.
3. Foster S. and Duke J. A. 1990. Naphtalactose, a mild sedative compound in Catnip, also possess herbicidal and insect - repellant properties. In Peterson Field Guides, Eastern/ Central Medicinal plants. Houghton Mifflinco. New York.
4. Gbolade A. A. 2011. Plant derived insecticides in the control of malaria vectors. Journal of Tropical medicinal plants. 2: 91-97.
5. Herrera, A.P. and Vieto S.A. 1980. Insecticidal use of orange juice essential oil. Panama SPA, United states.
6. Moore S. A. Lengiett A. and Hill N. 2002. Field evaluation of three plants based insect repellent against malaria vector in VACA DIE 2 province of the Bollivan Amazon. Journal of American mosquito control Association 18: 107.
7. Oyedele A. O. Orafidiya L. O Lamikaura A. and Olaifa J.L. 2000. Volatility and Mosquito repellency of Hemizygia Welwitschii oil and its formulation. Insect science and its application. 20; 123-128.
8. Pathak N. Mitral P.K. Singh O.P. Vidya S. and Vasidevan P. 2000. Larval action of essential oil from plants against the vector mosquito. Anopheles Stephens {Liason}. Culex Quintus fascist us (Say) and Added Aegypti(L). Insect pest control. 42:53.
9. Sadick F. 1973. Handbook of nonprescription drugs. Editors G. Griffenhagun and L. Hawkins American Pharmacological association, Washington D.C.
10. Thorselli W. Mikiver A. Malander I. and Tunon H. 1998. Efficacy of plant extracts and oils as mosquitoe repellents. Phytomedicine 5:311-323.
11. Thoure Y. 2002. Malaria Vector control strategies and challenges in Africa, Mali. In Epidemiology of parasitic diseases. University of Mali press.
12. Trigger J.K. 1996. Evaluation of Eucalyptus based repellent against Anopheles spp in Tanzania. Journal of American Mosquito Control Association 12: 243.
13. WHO 1996. Disease sheet. Malaria - the current situation.
