Lophodermella concolor (Dearn.) Darker
(= Hypodermella concolor (Dearn.) Darker)
Ascomycotina, Rhytismatales, Hypodermataceae
Hosts: Lophodermella concolor is restricted to "hard" or "two-needle" pine species. In B.C., pine needle cast has been reported on lodgepole, ponderosa, and Scots pine.
Distribution: This disease is common in all regions of the province, particularly in the southern interior.
Identification: Infected stands have reddish discoloured foliage in May and June, turning straw-coloured by July (Figs. 53a, 53b). As the summer progresses, diseased needles on previous years growth are shed while new growth remains giving branches a "lion's tail" appearance (Fig. 53c).
Although new needles are infected during their first year of growth, there is little visual evidence of infection at this time. Damage occurs in the needle tissue over the winter, and needles turn red in the spring. Fruiting bodies (apothecia) are formed on dead and dying needles, appearing as shallow oval depressions that are concolorous with the needle surface (hence the name concolor) (Fig. 53d). Infected needles are shed at about the time that the apothecia mature, and spores are released during periods of wet weather, infecting new growth.
Microscopic Characteristics: Apothecia (hysterothecia) subhypodermal, concolorous, 0.4-0.8 x 0.3-0.4 mm, opening by a single slit. Asci subcylindric, 120-225 x 15-17 µm; ascospores unicellular, clavate, colourless, 45-60 x 4-8 µm.
Damage: Significant levels of defoliation occur in years following periods of moist summer weather favorable for infection. Increment loss and mortality may occur after repeated epidemics, particularly in young trees.
Remarks:Other fungi, including Hemiphacidium longisporum Ziller and Funk and Hendersonia pinicola Wehm., often invade needles infected with L. concolor, competing with, or parasitizing the Lophodermium (Fig. 53e). A related species of Lophodermella, L. montivaga Petre., can be distinguished from L. concolor by its elongate, brown fruiting structures, and that it tends to have a more northern distribution in the province.
Hunt, R. S. 1995. Pine needle casts and blights in the Pacific region. Can. For. Serv., Forest Pest Leaf. No. 43. Victoria, B.C.
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Figure 53a: Lodgepole pine infected with L. concolor.