| |
Biological control, in the life sciences, is the idea that pest organisms can be controlled by the manipulation of other living organisms, thus avoiding the use of indiscriminate, expensive and inefficient pesticides. Traditionally, this strategy has taken the form of the introduction of a potential predator or pathogen into the environment of the pest. This was often made possible because the pest organism itself had been introduced by man and had assumed a population of pestilential proportions precisely because it had been introduced without its natural enemies. The rabbit was introduced to Australia as a food and hunting resource but rapidly multiplied to become a serious pest, uncontrollable by shooting and trapping. It was controlled dramatically by the introduction to Australia of the virus which causes myxomatosis in rabbits.
Biological control often involves the use of insect predators, though careful studies must be carried out to ensure that the introduced species does not itself become an uncontrolled pest. Biological control can also be achieved by interfering with the reproduction of the pest, mainly by the introduction of huge numbers of sterile males. Chemicals called pheromones, which are the active components of animal scents, have been isolated and exploited to modify the behaviour of pest species; mole moths, for example, can be lured into traps baited with the pheromone which the female of the species normally releases to guide males towards her. It may also be possible to control pests using genetically engineered pathogens, provided the situation is sufficiently well understood. RB
See also niche; parasitism.Further reading A.J. Burn, Integrated Pest Management. |
|
