Pine Needle Casts
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Hagle, S.K; S. Tunnock; K.E. Gibson; and C.J. Gilligan. 1987. Field Guide to Diseases and Insect Pests of Idaho and Montana Forests. U.S. Department of Agriculture, Forest Service. State and Private Forestry, Northern Region. Missoula, Montana. Reprint 1990. Publication Number R1-89-54.
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Contents |
Hosts
Lodgepole pine – Lophodermella concolor. Ponderosa pine – Dothistroma pini, Elytroderma de formans. Western white pine – Dothistroma pini. Whitebark pine, limber pine – Lophodermella arcuata.
Distribution
Distribution of hosts.
Damage
Most severe needle casts of pines in Idaho and Montana are caused by these four fungi. One-year-old foliage is killed. Growth loss and occasionally mortality results from severe infections. Elytroderma needle cast causes witches brooms in branches and often will deform small trees.
Identification
Needles infected early in their development in the spring die in autumn of the same year or spring the following year. Needle casts are fairly host specific. The host identity can be used as a general indicator of needle cast species, particularly in situations of severe infection. Infections of these needle cast fungi on hosts other than those indicated above are usually minor. There are numerous other needle cast fungus species which occasionally become locally important.
Needle casts are usually most severe low in tree crowns (fig. 127). In situations of recurring infection, several years' complements of foliage may have been cast. On sites which are prone to chronic infection, only foliage less than a year old may be present on trees. Saplings are usually most severely affected. See comparisons of L. concolor (fig. 128), D. pini (figs. 129, 130), E. de formans , and L. arcuata.
Similar damages
Damages which cause general decline in pines, such as root disease or drought, mimic the symptoms of needle cast. Pine needle scale, black pineleaf scale, winter desiccation, and pine needle sheathminer all cause damages which can be confused with needle cast. Look for the specific symptoms and signs of each needle cast disease.
Comparison of Common Pine Needle Casts
| Primary Host | Symptoms | Fruiting Bodies | Fruiting Season | Needles Shed | |
|---|---|---|---|---|---|
| Lophodermella concolor | Lodgepole pine | Red-brown bands in summer and fall; entire needle tan in following spring | Tan cushions of fungus under flap of epidermis on tan needles | Late spring | 13 months following infection |
| Dothistroma pini var. linearis | Ponderosa pine | Distinct, red, transverse banding at random on needles; needles become tan in fall or spring following infection | Black dots in red bands | April-November | 15-24 months following infection |
| Dothistroma pine var. linearis | Western white pine | 1-year-old or older needles turn red or brown. Red transverse banding indistinct or absent | Black dots breaking through epidermis | April-November | Needles remain attached, drooping on twigs for 1-2 years following infection |
| Elytroderma deformans | Ponderosa pine | Needles gradually turn red-brown. Part of needle may remain green. Witches brooms. | Black slit in epidermis near base of needle | Mid-to late summer | 12-20 months following infection |
| Lophodermella arcuata | Whitebark pine, limber pine | Black lines on dead needles | Late spring | 13 months following infection |
References
- Anonymous. 1982. For. Insect & disease identification and management. USDA For. Serv., Northern Region; Idaho Dept. of Lands, Insect and Disease Control; Montana Dept. of State Lands, Division of Forestry. 192 p.
- Bega, R. V. 1978. Diseases of Pacific Coast conifers. USDA For. Serv. Ag. Hndbk. No. 521, 206 p.
- Boyce, J. S. 1961. Forest Pathology. McGraw-Hill Book Co., New York, NY. 572 p.
- Funk, A. 1981. Parasitic microfungi of western trees. Canadian Forestry Service, Pacific Forest Research Centre BX-X-222, 190 p.
- Hepting, G. E. 1971. Diseases of forest and shade trees of the United States. USDA For. Serv. Ag. Hndbk. No. 386, 658 p.
- Peterson, G. W. 1982. Dothistroma needle blight of pines. USDA For., Serv., For. Ins. & Dis. Leaflet 143, 6 p.
