Elm: Elm leafminer categories: Elm Elm Insects Ornamental trees Ornamentals revision date: 2024-06-05 08:28 Elm leafminer damagePhoto by: J. O’Brien Biology Elm leafminers feed by removing green tissue from between upper and lower surfaces of the leaves. Symptoms of feeding by the yellowish or green larvae include large brown to gray brown blotches on the […]
Elm: European elm scale categories: Elm Elm Insects Ornamental trees Ornamentals revision date: 2024-06-05 02:04 European elm scalesPhoto by: A.L. Antonelli Biology The European elm scale is a reddish-brown to purplish scale surrounded by a conspicuous fringe of white, waxy material. They sometimes resemble mealybugs. The mature females are about 1/8″ in diameter. The crawlers […]
Elm: Bacterial wetwood (Slime flux) categories: Elm Elm Diseases Ornamental trees Ornamentals revision date: 2022-11-22 01:14 Elm bacterial wetwood (slime flux)Photo by: R.S. Byther Biology Wetwood or slime flux is a bacterial infection common in elm and poplar. The infection causes production of large amounts of moisture in the wood of trunks or large branches. […]
Elm: Dutch elm disease categories: Elm Elm Diseases Ornamental trees Ornamentals revision date: 2022-11-22 01:10 Dutch elm diseasePhoto by: C.R. Foss Biology Dutch elm disease is a fungal infection transmitted by elm bark beetles. Bark beetles carry disease spores on their bodies and infect trees when they feed. Leaves above the infection site turn yellow […]
Elm: Nectria canker categories: Elm Elm Diseases Ornamental trees Ornamentals revision date: 2022-11-22 12:56 Nectria canker fruiting bodies on branchPhoto by: R.S. Byther Biology Nectria canker is a fungal disease often found on twigs and branches that have been weakened by drought, frost damage, insect damage, or other diseases. Cankers are initially distinguished by discolored […]
Elm: Spiny elm caterpillar categories: Elm Elm Insects Ornamental trees Ornamentals revision date: 2024-06-07 06:33 Spiny elm caterpillarPhoto by: S.J. Collman Biology The spiny elm caterpillar is the larval stage of the mourningcloak butterfly. The adult is approximately 2 1/2″ across, with purplish-brown to black wings bordered by a creamy yellow stripe and a row […]
Dogwood: Brown soft scale categories: Dogwood Dogwood Insects Ornamental trees Ornamentals revision date: 2024-06-05 02:04 Brown soft scalesPhoto by: R.S. Byther Biology Brown soft scales are yellowish to dark brown (adults are usually darker). They are found mainly on twigs, although young scales may also be found on foliage. They overwinter as immatures on host. […]
Dogwood: Lecanium scale categories: Dogwood Dogwood Insects Ornamental trees Ornamentals revision date: 2024-06-05 02:04 Lecanium scales on twigPhoto by: R.S. Byther Biology Lecanium scales are rounded brown (or mottled) insects. Adults are from 1/8″ to 1/4″ in diameter. Lecanium scales produce large amounts of sticky honeydew, which may have sooty mold growing on it. They […]
Dogwood: Anthracnose categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals revision date: 2024-06-05 02:07 Dogwood anthracnose on leavesPhoto by: R.S. Byther Biology Dogwood anthracnose is a fungal disease of leaves and twigs. It is found mainly on the native dogwoods, especially Pacific dogwood, but can also infect some ornamental dogwoods. The leaves display small to large […]
Dogwood: Armillaria root rot categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals revision date: 2022-11-22 11:52 White fungal mat of Armillaria root rot infecting trunkPhoto by: C.R. Foss Biology Armillaria root rot is a fungal disease transmitted between plants by root contact. Armillaria is often found in newly cleared soils or ones which have been flooded. […]
Dogwood: Collar rot categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals revision date: 2022-11-22 11:49 Phytophthora root rot infecting trunkPhoto by: R.S. Byther Biology Collar rot is caused by a soilborne fungus which usually infects the plant through wounds on the trunk. It can also infect roots. A canker develops on the trunk near the soil […]
Dogwood: Leaf scorch and leaf roll categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals revision date: 2022-11-22 11:46 Dogwood leaf scorchPhoto by: R.S. Byther Biology Leaf scorch and leaf roll are results of stress. Leaf scorch is characterized by browning of the tips and margins of the leaves. Leaf roll is a puckering and upward rolling […]
Dogwood: Powdery mildew categories: Dogwood Dogwood Diseases Ornamental trees Ornamentals revision date: 2024-06-05 10:24 Powdery mildew on dogwood leafPhoto by: J. Chushcoff Biology Dogwood powdery mildew is caused by a fungus. It infects leaves, current-year twigs, blossoms, fruit, and buds. The first symptom is often yellow patchy areas on a leaf that become necrotic. White, […]
Dogwood: Oystershell scale categories: Dogwood Dogwood Insects Ornamental trees Ornamentals revision date: 2024-06-05 08:28 Severe oystershell scale infestation on twigPhoto by: Unknown Biology Oystershell scale insects are usually found on trunks, branches, and twigs. They occur less frequently on the leaves and other plant parts. The mature scale is approximately 1/8″ long, brownish or gray […]
Crabapple: Aphids categories: Crabapple Crabapple Insects Ornamental trees Ornamentals revision date: 2024-06-05 02:04 Aphid colony on leafPhoto by: A.L. Antonelli Biology Aphids on crabapples may be green or reddish in color. They typically feed near the tip of growing shoots, sometimes deforming leaves and stunting terminal growth. Fruit may also be deformed. These soft-bodied insects […]
Crabapple: Apple-and-thorn skeletonizer categories: Crabapple Crabapple Insects Ornamental trees Ornamentals revision date: 2024-06-07 06:33 Apple-and-thorn skeletonizer caterpillar feeding on leafPhoto by: A.L. Antonelli Biology The adult of the apple-and-thorn skeletonizer is a small dark-brown moth. It overwinters as a pupa or an adult, with the females laying eggs in the spring. The caterpillars are yellow-green […]
Crabapple: Leafrollers and leaftiers categories: Crabapple Crabapple Insects Ornamental trees Ornamentals revision date: 2024-06-07 06:33 Rhododendron leafroller leaf damagePhoto by: Unknown Biology Several species of caterpillars will roll and tie leaves of fruit trees. Characteristic signs of feeding include leaves that are webbed, rolled, and tied, often with frass in the webbing. Damaged leaves often […]
Crabapple: San Jose scale categories: Crabapple Crabapple Insects Ornamental trees Ornamentals revision date: 2024-06-05 02:04 San Jose scale closeupPhoto by: K. Grey Biology San Jose scale is an armored (hard) scale found on many deciduous trees and shrubs including (but not limited to) apple, cherry, elm, maple, poplar, and willow. The scale insects are about […]
Crabapple: Powdery mildew categories: Crabapple Crabapple Diseases Ornamental trees Ornamentals revision date: 2024-06-05 10:40 Powdery mildew on apple leavesPhoto by: R.S. Byther Biology Powdery mildew of crabapple is typically seen on the foliage, but may also occur on twigs, blossoms, and fruit. Characteristic patches of white, powdery fungus develop on the leaves and terminal shoots. […]
Crabapple: Scab categories: Crabapple Crabapple Diseases Ornamental trees Ornamentals revision date: 2024-06-05 02:07 Apple scab on leaves and young fruitPhoto by: R.S. Byther Biology Scab of crabapples is caused by the same fungus which causes scab on apple and hawthorn. The disease infects during wet weather in the spring and initially causes small, pale, watersoaked […]