CATS Southwest Pest and Disease 2

Question 1

Which fungal pathogen causes the 'witches' broom' symptom commonly observed on hackberry trees in the Southwest?

Accepted Answer

Eriophyid mite and powdery mildew complex

Answer

Phytophthora ramorum

Answer

Cytospora canker

Answer

Armillaria mellea

Question 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?

Accepted Answer

Fraxinus velutina (Arizona ash)

Answer

Fraxinus pennsylvanica (green ash)

Answer

Fraxinus americana (white ash)

Answer

Fraxinus latifolia (Oregon ash)

Question 3

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

Accepted Answer

Marssonina leaf spot

Answer

Iron chlorosis

Answer

Septoria canker

Answer

Cytospora blight

Question 4

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

Accepted Answer

Girdling branches at crotch unions with pitch masses

Answer

Mining needles in fascicles

Answer

Boring through the root collar

Answer

Feeding on pollen cones

Question 5

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

Accepted Answer

Poorly drained, heavy clay or compacted soil with overwatering

Answer

Sandy, well-drained caliche-free soil

Answer

Highly alkaline soil above pH 9.0

Answer

Extremely dry, drought-stressed soil

Question 6

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

Accepted Answer

Secondary pest that primarily attacks stressed or weakened piñons

Answer

Primary pest that attacks healthy vigorous piñons

Answer

Defoliator that feeds on piñon needles

Answer

Gall-forming insect that distorts piñon shoots

Question 7

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

Accepted Answer

Pruning 8–12 inches below visible infection with sanitized tools

Answer

Applying systemic fungicides to the root zone

Answer

Injecting oxytetracycline into the trunk

Answer

Applying copper bactericide after bloom only