Foliar Diseases
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
Lophodermella Needle Cast
Lophodermella cerina (Darker) Darker

Host:  Ponderosa pine

Figure 184. Figure 184. Lophodermella needle cast on 1-year needles before bud break.

Symptoms/Signs:  Lophodermella cerina infects the needles of seedlings, saplings, and the lower crown of larger trees. Current year needles become infected and turn brown and die by early summer of the following year. After the next bud break, green current year needles and brown 1-year needles give the tree a distinctive appearance. The brown needles are “cast” prematurely compared to normal needle drop. Repeated infection occurs only with favorable weather conditions and results in thin crowned trees.

Biology:  Fruiting bodies are short, oval, light brown, and easily overlooked. The spores mature after the needles have been cast. They infect new needles shortly after bud break. Spores germinate and infect needles directly through the epidermis. Infected needles extend normally and are usually killed by the fungus before the next year’s needles emerge.

Figure 185. Figure 185. Diseased 1-year needles are cast in late summer leaving current year and 2-year+ needles.

Effects:  Although rare, growth loss is the primary long-term effect of needle cast. Successive years of infection are usually the result of repeated abnormally high rainfall in spring and early summer. Though trees can be killed if infection is repeated for several years in a row, they are more often predisposed to other pests.

Similar Insects and Diseases:  From a distance, trees with needle cast symptoms may be mistaken for those affected by winter damage, deicing salt damage, or needle miners. On close inspection, needle cast needles are completely brown with dark fruiting bodies present. Winter damage, salt damage, and needle miner needles often have brown needle tips with green bases.

References:  71, 83, 93