B.F. Bachelor of Forestry Forest Entomology and Pathology 3

Question 1

What is 'biological control' as used against forest insect pests?

Accepted Answer

Using living organisms such as parasites, predators, or pathogens to suppress pest populations

Answer

Using genetically engineered trees that are resistant to insects

Answer

Banning pesticide use and allowing nature to regulate pest outbreaks

Answer

Manually removing insects from infested trees

Question 2

What is 'sudden oak death' (SOD) caused by?

Accepted Answer

The water mold Phytophthora ramorum, which causes bleeding cankers and rapid death in susceptible oak species

Answer

Bark beetle outbreaks triggered by drought stress in oaks

Answer

A bacterial pathogen spread by leafhoppers in California

Answer

An introduced wood-boring beetle from Asia affecting California oaks

Question 3

What does 'economic injury level' (EIL) mean in pest management?

Accepted Answer

The minimum pest population density that will cause economic damage equal to the cost of control

Answer

The cost of applying pesticides to a forest stand

Answer

A USDA regulatory threshold above which pesticide use is mandated

Answer

The amount of timber loss acceptable before a stand is considered uneconomical

Question 4

How do bark beetles locate and colonize host trees?

Accepted Answer

Using chemical cues including host volatiles and pheromones to locate weakened or susceptible trees

Answer

Randomly attacking the nearest available tree

Answer

Following the movement of other insects as a behavioral guide

Answer

Being attracted solely to trees with mechanical injuries

Question 5

What is the 'disease triangle' concept in forest pathology?

Accepted Answer

The interaction of a susceptible host, virulent pathogen, and favorable environment required for disease to occur

Answer

A geographic mapping tool for tracking disease spread across three forest zones

Answer

A classification of diseases into three types: foliar, stem, and root diseases

Answer

The three stages of disease progression from infection to tree death

Question 6

What is 'Armillaria root disease' and why is it significant in US forestry?

Accepted Answer

A native fungal root disease caused by Armillaria species that kills weakened trees and persists in soil as a chronic problem

Answer

An introduced Asian root pathogen that arrived in the US in the 1990s

Answer

A bark disease of conifers caused by honey mushroom spores

Answer

A vascular wilt disease that spreads through root grafts among adjacent trees