Juniper: Spruce spider mite categories: Conifers Juniper Juniper Insects Ornamentals revision date: 2024-06-05 08:28 Spruce spider mite adultPhoto by: A.L. Antonelli Biology Foliage of plants infested with spruce spider mites is often speckled, stippled, or bleached-looking. Severely damaged leaves or twigs may drop. Some species of spider mites produce fine webbing on the plant. They […]
Juniper: Dieback categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Shoot tip dieback on arborvitaePhoto by: R.S. BytherPhoto by: R.S. Byther Biology Dieback observed on juniper is often caused by cultural or environmental factors rather than pathogenic diseases or insect infestations. Extensive foliar dieback of juniper suggests that the site is less than […]
Juniper: Magnesium deficiency categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Biology Magnesium (Mg) deficiency is a result of improper nutrition. A juniper lacking sufficient magnesium develops yellowing or dead foliage in the center and grows slowly. Older tissues are affected first. Magnesium deficiency may resemble damage caused by Phomopsis twig blight. Management […]
Juniper: Pear trellis rust categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Symptoms on Juniperus sp.Photo by: P. Kapitola, Bugwood.org Biology Pear trellis rust is a fungal disease that attacks pear trees and junipers. It is commonly reported on pear leaves in western Washington. Like many rust diseases, pear trellis rust requires both […]
Juniper: Phomopsis twig blight categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Phomopsis twig blight on juniperPhoto by: R.S. Byther Biology Infection by Phomopsis begins with young leaves at the tips of shoots and can occur any time tender young foliage is available. Initially, small yellow spots appear on the scale-like leaves. As […]
Juniper: Phytophthora root rot categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Phytophthora root rot on juniperPhoto by: R.S. Byther Biology Phytophthora root rot is usually a problem only in areas with poor drainage or where flooding occurs. The fungus attacks the roots, which rot and die. The infection moves up into the […]
Juniper: Rust categories: Conifers Juniper Juniper Diseases Ornamentals revision date: 2023-02-07 12:00 Juniper rustPhoto by: R.S. Byther Biology Several types of rusts infect junipers. The alternate hosts for most of the rusts are in the rose family, including plants such as hawthorn, cotoneaster, and apple. Infected junipers develop round or elongate galls on the branches. […]
Hemlock: Coneworms categories: Conifers Hemlock Hemlock Insects Ornamentals revision date: 2023-01-31 12:00 Coneworm larvae on pinePhoto by: K. Grey Biology Coneworms attack trees by boring into green cones, shoot tips, stems, and trunks. They are particularly attracted to wound sites. Coneworm feeding results in the dieback of affected twigs. Injured twigs often can be distinguished […]
Hemlock: Hemlock scale categories: Conifers Hemlock Hemlock Insects Ornamentals revision date: 2024-06-05 08:29 Hemlock scalePhoto by: R. Van Denburgh Biology Hemlock scales feed on the needles of Eastern hemlock (Tsuga canadensis) and spruces (especially Colorado blue). Adult scales are round to oval, dark gray or black in color, and about 2 mm (1⁄10″) in diameter. […]
Hemlock: Hemlock woolly adelgid categories: Conifers Hemlock Hemlock Insects Ornamentals revision date: 2024-06-05 10:40 Hemlock woolly adelgidPhoto by: R.S. Byther Biology Hemlock adelgids are aphid-like insects. They appear as white, woolly tufts on the bark and needles. Trees with severe infestations may be stressed, predisposing them to other insect and disease problems. Needles drop prematurely, […]
Hemlock: Annosus root rot categories: Conifers Hemlock Hemlock Diseases Ornamentals revision date: 2023-01-31 12:00 Annosus root rot decayed wood with black flecksPhoto by: B.M. Johnson Biology Annosus root rot is caused by the fungus Heterobasidion annosum. This native soil pathogen is often in large old tree stumps. It can live several decades as a saprophyte […]
Hemlock: Phytophthora root rot categories: Conifers Hemlock Hemlock Diseases Ornamentals revision date: 2023-01-31 12:00 Dieback on creeping hemlock due to Phytophthora root rotPhoto by: R.S. Byther Biology Phytophthora root rot is usually a problem only in areas with poor drainage or where flooding occurs. The fungus attacks the roots, which rot and die. Phytophthora root […]
Douglas Fir: Aphids categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 08:29 Giant conifer aphids on pinePhoto by: A.L. Antonelli Biology The aphids that infest Douglas fir are quite large—up to 1⁄5″ long. They may range in color from gray to brownish to dark. The aphids establish large colonies on the twigs […]
Douglas Fir: Coneworms categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Coneworm larvae on pinePhoto by: K. Grey Biology Coneworms attack Douglas fir by boring into shoot tips or stems, especially around wounds, and feeding on the soft bark tissues. The portion of the branch beyond the injured point may die […]
Douglas Fir: Cooley spruce gall adelgid categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 10:40 Douglas-fir Cooley spruce gall adelgidsPhoto by: A.L. Antonelli Biology This aphid-like insect feeds on newly growing needles. Adelgids appear as woolly or cottony tufts on the needles, with heavily infested trees appearing “frosted” or flocked. Small purplish […]
Douglas Fir: Douglas fir needle midge categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Douglas-fir needle midgePhoto by: R.S. Byther Biology The tiny white larvae of the Douglas fir needle midge mine the inside of needles, which become yellowed and distorted. Infested needles often have a sharp bend at the injury […]
Douglas Fir: Douglas fir tussock moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-04-12 12:00 Douglas-fir tussock mothPhoto by: R.D. Akre Biology Douglas fir tussock moth larvae start at branch tips at the top of the tree and work down, feeding mainly on the new foliage and causing severe defoliation. They may […]
Douglas Fir: Douglas fir twig weevil categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2024-06-05 10:40 Douglas-fir twig weevil on noble firPhoto by: Unknown Biology The Douglas fir twig weevil is a small, wingless, grayish-black beetle with white markings and sometimes pinkish spots. The adult lays eggs in twigs in the summer. The […]
Douglas Fir: Sequoia pitch moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-01-31 12:00 Sequoia pitch mothPhoto by: S.J. Collman Biology The larvae of the sequoia pitch moth feed by boring into branches or trunks. At the point where the larva enters the wood, small to large masses of white to pinkish […]
Douglas Fir: Silverspotted tiger moth categories: Conifers Douglas Fir Douglas Fir Insects Ornamentals revision date: 2023-04-12 12:00 Douglas-fir silverspotted tiger mothsPhoto by: A.L. Antonelli Biology The caterpillars of the silverspotted tiger moth feed on the needles, often “tenting” branches with dirty-looking webs. Feeding occurs through fall and winter, with webs becoming more noticeable by spring. […]