Several insects damage eastern redcedar trees but rarely cause serious permanent damage (5). Roots of seedlings are very susceptible to attack by nematodes and grubs. The foliage is eaten by bagworms (Thyridopteryx ephemeraeformis) and spruce spider mites (Oligonychus ununguis), both of which can completely defoliate trees. The eastern juniper bark beetle (Phloeosinus dentatus) attacks the species but usually does not kill trees except when the attack is associated with the root rot fungus, Heterobasidion annosum. Another bark beetle (Phloeosinus canadensis) may feed on eastern redcedar. Several boring insects, including the black-horned juniper borer (Callidium texanum), cedartree borer (Semanotus ligneus), cypress and cedar borer (Oeme rigida), and pales weevil (Hylobius pales) will attack eastern redcedar. The juniper midge (Contarinia juniperina) is a gall insect pest of redcedar which bores into the twigs at the base of needles and kills the portion beyond the entrance hole. In addition to pales weevil, two other weevils, the arborvitae weevil (Phyllobius intrusus) and the strawberry root weevil (Otiorhynchus ovatus), feed on roots of eastern redcedar. The latter two weevils are also leaf feeders, along with the juniper webworm (Dichomeris marginella); a wax moth (Coleotechnites juniperella); a leaf roller (Choristoneura houstonana), a pest of windbreak and ornamental plantings; and a sawfly (Monoctenus melliceps). The Fletcher scale (Lecanium fletcheri) and juniper scale (Carulaspis juniperi) are two other commonly occurring insects that attack junipers.
Eastern redcedar, especially when weakened by stress or insects, is very susceptible to damage by the root rot fungus, Heterobasidion annosum. This disease is thought to cause the greatest damage over much of its range. Cubical rot fungi (Fomes subroseus and Daedalea juniperina) and juniper pocket rot fungus (Pyrofomes demidoffii) enter eastern redcedars through dead branch stubs and attack the heartwood. Several other minor heart-rot fungi infect eastern redcedar (21).
The major stem and foliage diseases of eastern redcedar are fungi known as cedar rusts in the genus Gymnosporangium. The most commonly known and widely spread species is cedar apple rust (G. juniperi-virginianae), which attacks trees in all stages of development. Because it is an alternate host to this disease, the presence of redcedar is a problem to apple growers. Other common species are G. clavipes, G. globosum, G. effusum, and G. nidus-avis. The latter fungus is widely distributed and produces witches' brooms (21). Important foliage diseases include Phomopsis blight (Phomopsis juniperovora) and Cercospora sequoiae blight, which also attack seedlings. Phomopsis blight has been difficult to control in nurseries, but newer developments show promise (12,32). Both blights can cause major losses to eastern redcedar in the field, but Phomopsis blight is not a serious problem after seedlings reach age 4.
Newly established seedlings are subject to frost-heaving, and foliage may occasionally be damaged by winter injury (23). Mice and rabbits may damage young eastern redcedar seedlings. Livestock generally avoid biting seedlings or trees but may trample the plants and their roots while grazing. During times of scarce food, deer will heavily browse eastern redcedar and destroy most reproduction (11,20). Redcedar withstands the weight of snow fairly well, but it has only moderate resistance to ice damage (8). Although the species is generally very tolerant to drought and temperature extremes, the author observed considerable mortality in west central Arkansas associated with the extremely hot, dry summer of 1980.
- Burns, Russell M., and Barbara H. Honkala, technical coordinators. 1990. Silvics of North America: 1. Conifers; 2. Hardwoods. Agriculture Handbook 654 (Supersedes Agriculture Handbook 271,Silvics of Forest Trees of the United States, 1965). U.S. Department of Agriculture, Forest Service, Washington, DC. vol.2, 877 pp. http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm
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