Phaeocryptopus gaeumannii

Swiss needle cast

Description

Swiss needle cast is considered to be less dangerous than Rhabdocline needle cast as the needle shedding occurs only after 2–3 years after infection. Needles are infected through the pores in May–June. The first infection symptoms are tiny black pycnidia on the bottom side of still healthy green needles in two parallel rows. This symptom appears only at the beginning of spring of the following year. After 2–3 years, the needles begin to turn brown from the tip, and then fall. This disease of P. menziesii is most dangerous to trees 10–40 years of age, especially between 20–30 years. The fungus was spread to Europe from North America in 1925, a few years after P. menziesii introduction.

Symptom

Tiny black pycnidia on the bottom side of still healthy green needles in two parallel rows. This symptom appears only at the beginning of spring of the following year.

Tree Species: Douglas Fir

Part of a plant- attacked: Leaf / Needle

Pest significance: Very harmful

Pest Category: Fungi

Invasive Species: Yes

Present in EU: Yes

Seasonal frequency of occurrence