Pest Identification and Management
Know the pest before you treat it
Correct identification drives every later decision: the product, the rate, the timing, and whether a pesticide is even needed. Candidates should be able to separate insects from mites and other arthropods, recognize the major orders (chewing vs. piercing-sucking mouthparts), and distinguish insect pests from diseases (fungi, bacteria, viruses) and weeds (grasses, broadleaves, sedges). Learn the difference between complete metamorphosis (egg, larva, pupa, adult - beetles, flies, moths) and incomplete metamorphosis (egg, nymph, adult - aphids, true bugs), because the stage present on the crop determines which life stage a product must target.
IPM and thresholds
Integrated pest management combines cultural, mechanical, biological, and chemical tactics. Key vocabulary: action threshold (pest density at which treatment is justified), economic injury level, monitoring/scouting, and resistance management (rotating mode-of-action groups). Questions often test the sequence: identify → monitor → compare to threshold → select tactic → evaluate.
Traps in questions
Watch for these: (1) describing a pest by the damage symptom rather than the organism - confirm the cause before recommending a chemical; (2) confusing mode of action with site of action; (3) assuming a broad-spectrum product is always best - it may harm beneficials and worsen outbreaks; (4) forgetting that the pest's feeding site (leaf underside, root, stem) affects spray placement.
Rule of thumb
Treat the stage you can reach and that causes the damage. A caterpillar in the soil cannot be controlled by a foliar spray aimed at the leaf surface. When a question gives you a life stage and an application method, check that they match.
Worked example
A scout finds 3 aphids per leaf on a crop whose threshold is 10 per leaf. The correct action is to continue monitoring, not spray - the population is below threshold, and beneficial insects may keep it in check.