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 ofa 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.