🐞 Biological Control — Parasitoids, Predators, and Microbial Agents

Nature's Own Pest Control

The previous lesson covered cultural, physical, and mechanical control — methods that modify the environment or physically remove pests. This lesson introduces the fourth IPM component: biological control, which harnesses living organisms to suppress pest populations.

In 1888, California's citrus industry was being destroyed by the cottony cushion scale — an invasive pest from Australia. Instead of chemicals, scientists introduced the Vedalia beetle (Rodolia cardinalis), a natural predator from Australia. Within two years, the scale was under complete control. This landmark success proved that nature's own enemies can be more effective than any chemical — and it launched the modern science of biological control.

Indian agriculture uses biological control extensively today. Trichogramma parasitoid wasps are released on millions of hectares of sugarcane and rice. Chrysoperla lacewings protect cotton from aphids. Understanding these natural enemies — who eats whom, who parasitises whom — is essential for both farming practice and competitive exams.