CDFA Pest Prevention Plant Regulation Practice Exam

What is Dutch elm disease classified as?

1. A. virus

2. B. bacteria

3. C. fungus

4. D. parasite

The correct answer is: C. fungus

Dutch elm disease is caused by a fungal pathogen, specifically the fungus Ophiostoma novo-ulmi and Ophiostoma ulmi. This disease results in the wilting and death of elm trees due to the fungus blocking the water-conducting vessels within the tree's trunk. The symptoms of Dutch elm disease typically manifest as yellowing and wilting leaves, which may affect entire branches, leading to the tree's decline. The classification of Dutch elm disease as a fungus is crucial because it informs the appropriate management strategies to control and prevent further spread. Understanding that it is caused by a fungus allows for the implementation of fungicidal treatments and proper sanitation efforts to remove infected trees and wood, reducing the likelihood of spreading the disease to healthy plants. Other classifications, such as virus, bacteria, or parasite, do not accurately describe the pathogenic nature of Dutch elm disease, emphasizing the importance of correct identification for effective disease management.