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Southwest Pest and Disease Flashcards

7 cards from real CATS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Southwest Pest and Disease flashcards as text
  1. Which fungal pathogen causes the 'witches' broom' symptom commonly observed on hackberry trees in the Southwest?

    Answer: Eriophyid mite and powdery mildew complex

    Hackberry witches' broom is caused by a combination of eriophyid mites and powdery mildew (Sphaerotheca phytoptophila) acting together.

  2. The Emerald Ash Borer (EAB) has been detected moving into New Mexico. Which ash species native to the Rio Grande riparian corridor is most at risk?

    Answer: Fraxinus velutina (Arizona ash)

    Fraxinus velutina (Arizona/velvet ash) is the native ash of the Southwest's riparian areas and is highly susceptible to EAB.

  3. A homeowner reports that their cottonwood tree has yellowing leaves with dark spots and premature defoliation each summer. The most likely cause is:

    Answer: Marssonina leaf spot

    Marssonina leaf spot (Marssonina populi) is a common fungal disease of cottonwoods causing dark spots and early leaf drop in the Southwest.

  4. Zimmerman pine moth larvae cause the most damage to ponderosa pines in the Southwest by:

    Answer: Girdling branches at crotch unions with pitch masses

    Zimmerman pine moth (Dioryctria zimmermani) larvae bore into branch crotches and the main stem, producing large pitch masses that can girdle branches.

  5. Which soil condition in Albuquerque's urban landscape most predisposes trees to Phytophthora root rot?

    Answer: Poorly drained, heavy clay or compacted soil with overwatering

    Phytophthora thrives in waterlogged, oxygen-depleted soils, making poorly drained compacted soils with excess irrigation the primary risk factor.

  6. The Piñon engraver beetle (Ips confusus) is best described as a:

    Answer: Secondary pest that primarily attacks stressed or weakened piñons

    Ips confusus is a secondary bark beetle that primarily colonizes drought-stressed, weakened, or recently dead piñon pines.

  7. Fire blight (Erwinia amylovora) on ornamental crabapple or pear in the Southwest is best managed during the growing season by:

    Answer: Pruning 8–12 inches below visible infection with sanitized tools

    Pruning well below the visible shepherd's crook infection margin with sterilized pruners is the primary in-season management tactic for fire blight.