The earliest observable symptoms are dark-green bands and tan spots or bands on the mature needles. The spots and bands later turn reddish-brown. The needles will begin to die back from the tip, but needle bases usually remain green. From the time symptoms are first noticed to the time of needle browning may take 2-3 weeks. Infected needles will drop prematurely.
Infection typically is most severe in the lower crown of the tree.
Life Cycle The Dothistroma fungus overwinters on infected needles. The infective spores are released during wet weather and dispersed by rainsplash throughout the growing season. Symptoms on newly infected tissue are especially obvious in early fall. Integrated Pest Management Strategies 1. Live with the disease.