CPA Pest Identification & Control Techniques 3 — Questions and Answers
Question 1: Codling moth larvae primarily damage which part of apple trees?
- Root system
- Bark and cambium layer
- Fruit interior (core) (Correct answer)
- Flower buds
Correct answer: Fruit interior (core)
Codling moth larvae bore into apple fruit and feed on the core and seeds, causing the classic 'wormy apple' damage.
Question 2: Which type of pheromone trap is used specifically to monitor adult moth populations?
- Aggregation pheromone trap
- Sex pheromone (lure) trap (Correct answer)
- Alarm pheromone trap
- Trail pheromone trap
Correct answer: Sex pheromone (lure) trap
Sex pheromone traps use synthetic female sex pheromones to attract adult male moths for population monitoring and pest forecasting.
Question 3: A field has plants with wilting that does not respond to irrigation. Roots show C-shaped white grubs. These are larvae of:
- Wireworms (click beetles)
- Japanese beetle or other scarab beetles (Correct answer)
- Corn rootworm
- Cutworm moths
Correct answer: Japanese beetle or other scarab beetles
C-shaped white grubs with a distinct head capsule are larvae of scarab beetles such as Japanese beetle, which feed on plant roots causing wilting.
Question 4: Which cultural control method is most effective at reducing overwintering populations of corn rootworm?
- Applying fungicide in fall
- Rotating corn fields to a non-host crop such as soybeans (Correct answer)
- Increasing irrigation frequency
- Deep plowing in midsummer
Correct answer: Rotating corn fields to a non-host crop such as soybeans
Corn rootworm eggs are laid in corn fields and larvae require corn roots to survive, so rotating to a non-host crop starves emerging larvae.
Question 5: Powdery white coating on leaf surfaces accompanied by distorted new growth is characteristic of which pest or disease agent?
- Downy mildew (oomycete)
- Powdery mildew (fungus) (Correct answer)
- Two-spotted spider mite feeding damage
- Thrips feeding scars
Correct answer: Powdery mildew (fungus)
Powdery mildew is a fungal disease that produces a characteristic white powdery coating on leaf surfaces and causes distortion of new growth.
Question 6: The economic threshold (ET) in IPM is defined as the pest density at which:
- The pest population is first detected in the field
- Control action must be taken to prevent the economic injury level from being reached (Correct answer)
- Crop damage becomes visible to the naked eye
- The pesticide cost equals the value of the crop lost
Correct answer: Control action must be taken to prevent the economic injury level from being reached
The economic threshold is the pest density at which management action must be initiated to prevent populations from reaching the economic injury level.
Question 7: Which feature distinguishes a true bug (Order Hemiptera) from a beetle (Order Coleoptera)?
- True bugs have complete metamorphosis; beetles have incomplete metamorphosis
- True bugs have piercing-sucking mouthparts and leathery forewings; beetles have chewing mouthparts and hard elytra (Correct answer)
- True bugs always have wings; beetles are always wingless
- True bugs have three pairs of legs; beetles have four pairs
Correct answer: True bugs have piercing-sucking mouthparts and leathery forewings; beetles have chewing mouthparts and hard elytra
True bugs (Hemiptera) have piercing-sucking mouthparts and forewings that are partly leathery and partly membranous, while beetles have chewing mouthparts and fully hardened wing covers (elytra).
CPA Pest Identification & Control Techniques 3
Codling moth larvae primarily damage which part of apple trees?