Pest Identification and Control
Integrated Pest Management (IPM)
The exam frames pest control through IPM: a decision process combining cultural, mechanical/physical, biological, and chemical controls, with pesticides as one tool - not the default. Know the IPM steps: identify the pest, monitor/scout, set an action threshold, choose controls, evaluate results. Understand economic threshold (the pest level at which treatment prevents economic loss) versus action threshold.
Identification and biology
You must be able to distinguish pest groups - insects, weeds, plant pathogens, nematodes, and vertebrates - and know that correct identification drives every later choice. Understand key insect life stages (egg, nymph/larva, pupa, adult) and that the stage present affects which control works. Know weed categories: grasses vs. broadleaves, annuals vs. biennials vs. perennials, and how selective vs. nonselective and pre-emergent vs. post-emergent herbicides differ. Recognize pesticide resistance and resistance-management practices such as rotating mode of action (not just product name).
Traps to watch
A frequent trap is treating a symptom as the pest - e.g., yellowing from a nutrient deficiency mistaken for disease. Another is confusing mode of action with site of action and assuming different brand names mean different modes of action. Watch questions that reward prevention (cultural controls, sanitation) over reactive spraying. Also know that biological controls can be disrupted by broad-spectrum insecticides.
Worked example / rule of thumb
Rule of thumb: Identify first, then decide. Example: a scout finds aphids below the economic threshold. The correct IPM answer is to monitor and wait, not spray - treating below threshold wastes money and promotes resistance. If the same field shows resistance after repeated use of one herbicide group, the fix is to rotate to a different mode of action, not simply increase the rate.