Foliar Diseases
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
True Fir Needle Cast
Lirula abietis-concoloris (Mayor ex Dearn.) Darker

Host:  White fir and subalpine fir

Figure 191. Figure 191. Death of 2-year needles caused by true fir needle cast.

Symptoms/signs:  Dark brown or black elongate fruiting bodies are found on second year needles. The fruiting bodies extend down the center of the lower needle surface for almost the full length.

Biology:  Infection begins on young, developing needles during periods of rainfall. Fruiting structures mature on these needles the following spring and needles turn brown.

Effects:  Lirula abietis-concoloris occurs sporadically and infects only newly emerged needles. Damage is rare since it takes several years of favorable weather for repeated infection to defoliate trees and affect growth and vigor.

Similar Insects and Diseases:  None.

References:  83, 93