1.0 INSECTICIDES (General Overview)
is a substance or a mixture of substances used for killing insects. It is
well known fact that many protozoal bacteria diseases are transmitted from man
to man by insects. One may combat these diseases not only by means of prohylactic
drugs but also by the destruction of the insects carriers.
Insecticide is a chemical compound
that is lethally toxic to insects either by ingestion or by body contact. It is
applied to vegetation, crops and insect breeding areas either as liquid spray
or as dry powder.
They are used in agriculture,
medicine, industry and household. The use of insecticides is believed to be one
of the major factors behind the increase in agricultural productivity in 20th
Nearly, all insecticides have the
potential to significantly after ecosystem, many are toxic to human and others
are concentrated in food chain. It is necessary to balance agricultural needs
with environmental and health issues when using insecticides. It is crucially
important that all the rural areas in Nigeria are being educated on the need to
eradicate insects especially mosquitoes that might breed around the environment
and transmit malaria to people living within the enclave.
Integrated Pest Management (IPM) in
the home being with restricting the availability of insects of three vital
commodities; shelter, water and food. If insects become a problem despite such
measures, IPM seeks to control them using the safest possible methods targeting
the approach to the particular pest.
Years now, efforts are geared towards
controlling malaria infestation both in urban and rural areas. A lot of
measures are being taken to reduce the number of death as a result of malaria.
We hear now and then that numbers
being quoted by the analyst that died of malaria attack. Thus, free mosquitoes
treated nets are always distributed to families and individuals all in a bid to
reduce malaria attack from mosquito bite.
In the light of this, it is necessary
to study God-given substances in this case, plant that has embedded substances that
will help man combat mosquitoes or at least reduce infestation to the barest
OF THE STUDY/WORK
purpose of this work is to produce mosquito repellants using orange peels (cestrum) wastes perse, which will save
the cost of production and purchase, thereby increasing its availability
especially in the rural areas. If the work is successful, production of
mosquitoes repellants using orange peels will provide source of employment to
our teaming youths and also make mosquito repellant within the reach of
everybody, thereby reducing the number of death due to malaria caused by
OF THE STUDY
peels (cestrum) will be prepared and
used for the production of mosquito coil, which ignited, will repel mosquitoes
within the limit of the smoke. The produced coil will be tested for the
effectiveness performance. Cost analysis should also be taken to know weather
mass production will be more effective or not.
1.3.1 HISTORY ASPECT OF MOSQUITO REPELLENT
various types of substances have been used to repel mosquitoes. These include
such things as smoke, plant extracts, oil, tars, muds, etc.
insects repellants technology became more sophisticated, individual compounds
were discovered and isolated. This allows the formulation of new and more efficient
forms of mosquito repellants.
first truly effective active ingredient used in mosquito repellants was
citronella oil. This material is a herbal extract derived from the
citronella plant, an Asian grass. While citronella has been used for centuries
for medical purposes, its repellence was only accidentally discovered in 1901,
when it was used as a hairdressing fragrance. Since citronella oil is a fragrant material, it is thought that the
chemical terpenes of which it is composed are responsible for its repellant
does repel mosquitoes, but it has certain characteristics which limit its
effectiveness. For example, it is very volatile and evaporates so quickly from
the surface to which it is applied. Also, large amount are needed to be
effective. The disadvantages of using citronella
oil prompted researchers to study alternative synthetic compounds many of the
early attempt at creating synthetic insect repellants were initiated by the
Unites State military. Out of this research, the discovery of the repellant
dimethylphthalate in 1929. This material showed a good level of effectiveness
against certain insect species, but it was ineffective against others. Indalone
was found to repel insect in 1937 and Rutgers 612
(2-ethyl-1,3-hexane diol) was synthesized soon after. Like dimethylpthalate,
these materials had certain limitations which prevented their widespread
none of the available materials were ideal repellents, research into new
synthetic materials continued. In 1955, scientists synthesized DEET
(n-n-diethyl-netatoluamide) currently the most widely used active ingredient
for mosquito repellents.
its discovery, repellent manufacturers developed many different forms in which
to deliver DEET, such as creams, lotions and aerosols.
1.3.2 CLASSIFICATION OF INSECTICIDE
are usually classified into the following three classes.
STOMACH OR INTERNAL
insecticides which are taken up by the insects are called stomach poisons or
insecticides. Example, Boric acid.
CONTACT OR EXTERNAL
insecticides destroy the insect simply by external bodily contact. Example
insecticides act on the insects through the respiratory system. Example
hydrogen cyanide, carbon disulphide, nicotine, p-dichlorobenzene, etc. .
Insecticides may be applied as a
spray, liquid or in suspension, as a dust or as a gas.
1.3.3 CHEMICAL INSECTICIDES MAY BE CLASSIFIED
AS INORGANIC, NATURAL AND ORGANIC INSECTICIDES.
world war II nearly all the insecticides were inorganic compounds of which
arsenic, fluorine, sulphur and cyanide compounds were the most important. In recent
years, inorganic insecticides have been greatly displaced by organic compounds
in many applications.
The major disadvantage of inorganic
insecticides is their comparable toxicity to man and other warm blooded
animals. Upon handling and so as residues on food products.
SOME INORGANIC INSECTICIDES
Sulphur and sulphur compounds
NATURAL OR PLANT
Plant materials yield some of the most
widely used insecticides and many of them are being supplemented by the
synthetic organic insecticides. The roots stem, leaves or flowers may be finely
grounded and used as such or active parts may be extracted and used either
alone or with other toxicants and auxiliary materials.
SOME NATURAL INSECTICIDES
A typical organic insecticide is DDT
(Dichlor-Diphenyl-Trichloroethane) with IUPAC name