Pest Identification and Integrated Pest Management
Identify before you treat
Accurate identification is the foundation of every control decision. Learn to distinguish the pest from look-alikes and from beneficial organisms, and learn to read signs (the pest itself, frass, egg masses) versus symptoms (yellowing, wilting, stunting, necrotic spots). Many exam questions describe damage and ask for the cause: chewing injury with missing tissue points to caterpillars or beetles; stippling and webbing suggest spider mites; cupping or strapping of new growth suggests growth-regulator herbicide injury, not a disease. Weeds require knowing grass versus broadleaf, life cycle (annual, biennial, perennial), and whether the plant spreads by seed, rhizome, or tuber - because perennial root systems demand different tactics than annual seedlings.
The IPM pyramid
Integrated pest management combines cultural controls (resistant varieties, sanitation, crop rotation, planting date, fertility and irrigation management), mechanical/physical controls (cultivation, mulching, exclusion, traps), biological controls (predators, parasitoids, pathogens, conservation of beneficials), and chemical controls used last and most selectively. The engine that drives IPM is monitoring - scouting, sweep nets, pheromone traps, sticky cards, and weather-based models such as degree days.
Thresholds
Know the difference between the economic injury level (EIL) - the pest density at which damage equals the cost of control - and the action threshold, the lower, earlier number at which you act to prevent reaching the EIL. Treating below threshold wastes money, selects for resistance, and disrupts natural enemies, sometimes triggering secondary pest outbreaks or resurgence.
Resistance
Resistance is a heritable shift in a pest population, not the same as the temporary flare from losing beneficials. Rotate mode-of-action groups (IRAC for insects, HRAC/WSSA for herbicides, FRAC for fungicides) and never rely on one chemistry repeatedly.
Rule of thumb
"Identify, monitor, decide, act, evaluate." If you cannot name the pest and its life stage, do not spray - you cannot select the right product, rate, or timing.