Dutch Elm Disease and Its Impact

The video, presented by Brian Huddleston from the Plant Disease Diagnostic Clinic, discusses Dutch Elm Disease, its history, and impact in the US, particularly on American Elm trees. The disease, caused by the fungus Ophiostoma ulmi and spread by bark beetles, was introduced to the US in the 1920s. A more aggressive species, Ophiostoma novo-ulmi, spread rapidly in the mid-20th century. The video explains the lifecycle of the fungus, how it infects trees, and the challenges in controlling the disease. Despite some resistant hybrids, American Elms remain vulnerable, and fungicide injections are suggested for protection.

What is the primary tree species affected by Dutch Elm Disease in the US?

• Red Oak

• American Elm

• Asian Elm

• European Elm

When was Dutch Elm Disease first introduced to the United States?

• 1940s

• 1930s

• 1920s

• 1950s

Which insect is primarily responsible for spreading Dutch Elm Disease?

• Asian longhorn beetle

• Gypsy moth

• European elm bark beetle

• Emerald ash borer

What was the more aggressive fungus species introduced in the 1940s?

• Ophiostoma novo-ulmi

• Ophiostoma himalayan

• Ophiostoma ulmi

• Ophiostoma americana

How do the larvae of the bark beetles contribute to the spread of the fungus?

• By spreading spores through the air

• By laying eggs on the roots

• By tunneling into the bark

• By eating the leaves

What is the tree's response to the infection by the fungus?

• Forming tyloses

• Dropping its branches

• Producing more leaves

• Growing faster

What is a major challenge in controlling Dutch Elm Disease today?

• Lack of public awareness

• Lack of resistant tree species

• High cost of fungicides

• Inability to identify infected trees

What is a potential benefit of dead Elm trees?

• They provide shade

• They produce morels

• They attract wildlife

• They improve soil quality

What is a suggested method to protect resistant American Elm trees?

• Regular pruning

• Fungicide injections

• Insecticide sprays

• Watering frequently

What is a limitation of the hybrid Elm trees bred for resistance?

• They require more water

• They are more susceptible to other diseases

• They do not have the same aesthetic appeal

• They grow too slowly