CPA Pest Identification and Management 2 — Questions and Answers
Question 1: Which characteristic best distinguishes a spider from an insect during field identification?
- Spiders have 8 legs and 2 body segments (Correct answer)
- Spiders have 6 legs and 3 body segments
- Spiders have wings in the adult stage
- Spiders have antennae and compound eyes
Correct answer: Spiders have 8 legs and 2 body segments
Spiders are arachnids with 8 legs and 2 body segments (cephalothorax and abdomen), while insects have 6 legs and 3 body segments.
Question 2: A grower reports yellowing leaves with fine webbing on the undersides. The most likely pest is:
- Two-spotted spider mite (Correct answer)
- Aphid
- Whitefly
- Thrips
Correct answer: Two-spotted spider mite
Two-spotted spider mites produce fine webbing on leaf undersides and cause stippling and yellowing through cell-content feeding.
Question 3: Which of the following is an example of a pheromone trap used in pest monitoring?
- Delta trap with a sex-attractant lure for moths (Correct answer)
- Yellow sticky card for fungus gnats
- Blue sticky trap for thrips
- Light trap for general insect surveillance
Correct answer: Delta trap with a sex-attractant lure for moths
Delta traps baited with sex-attractant pheromone lures are used to monitor specific moth species by attracting males.
Question 4: When scouting for soybean aphids, a pest manager counts the number of aphids per plant. This practice is called:
- Sequential sampling (Correct answer)
- Binomial sampling
- Absolute density estimation
- Presence-absence sampling
Correct answer: Sequential sampling
Sequential sampling involves counting organisms per sampling unit and stopping when the cumulative count crosses a decision boundary, reducing sampling effort.
Question 5: Glassy-winged sharpshooter is a significant pest primarily because it:
- Vectors Xylella fastidiosa, causing Pierce's disease in grapevines (Correct answer)
- Directly feeds on grape berries reducing yield
- Lays eggs inside vine shoots killing new growth
- Produces honeydew that promotes sooty mold on fruit
Correct answer: Vectors Xylella fastidiosa, causing Pierce's disease in grapevines
The glassy-winged sharpshooter transmits the bacterium Xylella fastidiosa, which causes Pierce's disease — a lethal threat to grapevines.
Question 6: Which life stage of a pest is MOST commonly targeted by systemic insecticides applied as a soil drench?
- Root-feeding larvae or soil-dwelling nymphs (Correct answer)
- Adult flying stage
- Eggs on leaf surfaces
- Pupae in crop debris
Correct answer: Root-feeding larvae or soil-dwelling nymphs
Systemic insecticides taken up through roots kill root-feeding larvae and soil-dwelling nymphs that directly contact treated root tissue or plant sap.
Question 7: In integrated pest management, the 'economic injury level' (EIL) is defined as:
- The pest density at which the cost of control equals the value of damage prevented (Correct answer)
- The pest density that causes the first visible crop damage
- The maximum pest density tolerable without economic loss
- The pest density below which no management action is needed
Correct answer: The pest density at which the cost of control equals the value of damage prevented
The EIL is the lowest pest population density at which the cost of control equals the economic damage it prevents, making treatment worthwhile.
CPA Pest Identification and Management 2
Which characteristic best distinguishes a spider from an insect during field identification?