CAC Pest Management & Integrated Pest Management (IPM) 2 — Questions and Answers
Question 1: Pesticide resistance management best practices include which of the following strategies?
- Applying the same pesticide class repeatedly to ensure complete control
- Rotating between pesticide classes with different modes of action (Correct answer)
- Using sub-lethal pesticide rates to reduce selection pressure
- Restricting pesticide use to only one application per season regardless of pest levels
Correct answer: Rotating between pesticide classes with different modes of action
Rotating between pesticide classes with different modes of action prevents survivors from one class from being repeatedly selected, slowing the development of resistance in pest populations.
Question 2: Which biological control strategy involves releasing large numbers of a natural enemy in a single event to temporarily suppress a pest outbreak?
- Classical biological control
- Conservation biological control
- Augmentative biological control — inoculative release
- Augmentative biological control — inundative release (Correct answer)
Correct answer: Augmentative biological control — inundative release
Inundative releases involve releasing massive numbers of natural enemies to overwhelm a pest population in the short term, without expecting the released organisms to establish permanently.
Question 3: When reading a pesticide label, the signal word 'DANGER' indicates that the product is:
- Slightly toxic — LD50 greater than 5,000 mg/kg
- Moderately toxic — LD50 between 500 and 5,000 mg/kg
- Highly toxic — LD50 less than 50 mg/kg (Correct answer)
- Relatively non-toxic — no PPE required
Correct answer: Highly toxic — LD50 less than 50 mg/kg
The signal word DANGER (Toxicity Category I) indicates the highest level of acute toxicity, with oral LD50 values below 50 mg/kg, requiring strict safety precautions.
Question 4: A pre-harvest interval (PHI) on a pesticide label specifies:
- The minimum number of days between planting and first pesticide application
- The minimum number of days that must pass between the last pesticide application and harvest (Correct answer)
- The maximum number of pesticide applications allowed per crop season
- The minimum soil temperature required for effective pesticide activity
Correct answer: The minimum number of days that must pass between the last pesticide application and harvest
The pre-harvest interval (PHI) is the minimum number of days required between the last pesticide application and harvest to ensure residues decline to safe legal tolerances.
Question 5: The mode of action of organophosphate insecticides involves:
- Disrupting insect molting hormones (ecdysones)
- Inhibiting acetylcholinesterase, causing continuous nerve stimulation (Correct answer)
- Blocking sodium channels in nerve cell membranes
- Interfering with chitin synthesis during larval development
Correct answer: Inhibiting acetylcholinesterase, causing continuous nerve stimulation
Organophosphates inhibit acetylcholinesterase, the enzyme that breaks down the neurotransmitter acetylcholine, leading to continuous nerve firing, paralysis, and death in insects.
Question 6: Which of the following correctly describes the concept of pest resurgence?
- A pest population that develops resistance to a pesticide after repeated exposures
- A rapid increase in pest populations following pesticide application that kills natural enemies (Correct answer)
- The return of a pest species from overwintering sites in spring
- A secondary pest becoming economically important after target pest control
Correct answer: A rapid increase in pest populations following pesticide application that kills natural enemies
Pest resurgence occurs when a pesticide application kills natural enemies along with target pests, allowing surviving pest populations to rebound rapidly without biological suppression.
Question 7: Buffer zones required on pesticide labels near water bodies are primarily intended to:
- Prevent wind drift from damaging adjacent crops
- Protect aquatic ecosystems from pesticide runoff and drift (Correct answer)
- Ensure the applicator maintains safe distance from bystanders
- Reduce pesticide volatilization in high-temperature conditions
Correct answer: Protect aquatic ecosystems from pesticide runoff and drift
Buffer zones near water bodies are mandated to protect aquatic organisms from pesticide exposure through runoff or spray drift, as many pesticides are highly toxic to fish and aquatic invertebrates.
CAC Pest Management & Integrated Pest Management (IPM) 2
Pesticide resistance management best practices include which of the following strategies?