BIOLOGICAL METHODS OF
CONTROL
These methods of control include natural measures
without any reliance on chemical or mechanical devices. Carnivorous fish are
natural enemies of mosquito larva and have been utilized with advantage for
malaria control example Garibudia affinis
gold fish (Carassius auratus). It has
been shown that malaria could be controlled by the introduction of
a species of
carnivorous fish (Orechromis spilirus
pilurs) into mosquito breeding sites (Zahar, 1984). A survey conducted at
less and condition with two local species of Notobranchius an annual fish in
which the eggs resist drought between two rain seasons which are N. microlepis and N. cipineus but for control
of anopheles especially in the presence of weed and floating debris
(Maccormack, 1984).
However, Baccittus
sphaericus, a larvicidal bacterium is toxic to several genera of mosquito.
It’s capable of recycling even in highly polluted waters, and studies conducted
showed that it’s activities against the vector mosquito species depends on
larval gut enzyme activity which varies form species to species and prevents
the B. aphaericus toxin from entering the vectors haemolymph
(WHO, 1883).
GENETIC
METHOD OF CONTROL
This method is used to reduced the reproductive
potential of insects by altering the t hereditary malaria of the vector
species. Genetic control may be achieved by the following method, firstly,
irradiation where by males are sterilized by ionizing irradiation. The
principle is that the sterilized males seek out and mate with the wild female
in the natural environment.
1).
Administration and operational problem:
Administrative and operational problem
exist due to lack of trained personnel at all levels and inadequate development
of infrastructure that is required to support a properly organized malaria
control programmes. Other problems that has been encountered are lack of capability
and logistic support to ensure that adequate support of days are available at
all consumer points at all times (Beausoleil, 1984).
Population this preventing the hatching of their
eggs and lowering their reproductive capability.
Another method of genetic control is based on
crossing sibling species of an insect. This lead to hybrid male sterility and
when very large numbers of sterile males are released, their competition with
fertile male is so great that eventually the size of the succeeding generation
decreases below normal where transmission of malaria is possible.