Why can't turf simultaneously benefit from biological control methods and be pest free?

• A. Pesticide resistance develops
• B. Beneficial organisms require high temperatures
• C. There must be a low level of pest or prey insects for the predators to feed on
• D. Biological controls always cause pest resurgence

Answer: (C)

Biological control relies on natural enemies that must have prey to survive and reproduce. If the pest population is reduced to zero, the beneficial predators or parasitoids lose their food source, and their numbers decline. Once their populations fall, a new surge in pests can occur before the natural enemies can rebuild, leading to pest resurgence. In turf management, the aim is to keep pests below economic injury levels, not to eliminate them completely, so beneficials can persist and continue suppressing pests over time. So, you can’t be pest-free and still gain ongoing benefits from biological control because the mechanism depends on pests being present at low, sustained levels to support the natural enemies.