Pest Identification and Integrated Pest Management
IPM is a decision process
IPM combines prevention, monitoring, and the least-risk effective tactic. Know three terms: the economic threshold (pest density where control cost equals crop loss), the action threshold (the level at which you actually treat), and monitoring tools (sweep nets, sticky cards, pheromone traps, degree-days, weed counts).
Identify before you act
Insects: distinguish chewing injury (holes, defoliation) from piercing-sucking injury (stippling, curling, honeydew), and know which life stage you target - a soil drench aimed at larvae fails against adults. Weeds: grasses have round stems and parallel veins; broadleaves have net veins and two seed leaves; sedges have triangular stems ("sedges have edges") and favor wet sites. Diseases fit the disease triangle: susceptible host, virulent pathogen, and favorable environment; break any leg and the disease stops.
Tactics and resistance
Cultural, mechanical, biological, and chemical tools work best combined. For resistance management, rotate mode-of-action groups using IRAC, FRAC, and HRAC classifications, use full labeled rates, and mix or sequence different MOAs that both target the pest.
Traps
Calendar spraying is not IPM. A product that fails is often a resistance or timing failure, not a bad product. Broad-spectrum sprays can kill natural enemies and trigger secondary pest outbreaks or flaring.
Worked example
A scout finds aphids just below the threshold with abundant lady beetles present. The correct action is to keep monitoring rather than spray - the predator population is likely to hold the aphids under threshold.