What is the ecological principle behind the biological control method of managing with pest insects?
The ecological principle behind the biological control method of managing pest insects is predation, where predators keep prey populations under control.
In nature, predators play a crucial role in regulating prey populations. Without predators, prey species could achieve very high population densities and cause ecosystem instability. This principle is demonstrated by the example of the prickly pear cactus introduced in Australia, which spread rapidly and became invasive due to the absence of its natural predators. It was only controlled after a cactus-feeding predator (a moth) from its natural habitat was introduced. Thus, biological control uses natural predators to regulate pest insect populations.
Explanation
The question tests understanding of how predation is used as a biological control mechanism. The textbook explains that predators keep prey populations in check, and when exotic species lack their natural predators, they become invasive. The prickly pear cactus example illustrates how introducing a natural predator can control an invasive species. This is the basis of biological pest control in agriculture.
Solution Steps
Step 1: Identify the key ecological interaction - predation
Step 2: Explain how predators regulate prey populations and prevent ecosystem instability
Step 3: Support with the textbook example of prickly pear cactus control in Australia using a moth predator