Hawthorn Archives
Insects and diseases that can affect Hawthorn (Crataegus).
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Aphids
Many species of aphids or plant lice occur on ornamental trees and shrubs in Pennsylvania.
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Cedar Apple & Cedar Hawthorn Rust
Cedar-apple rust and closely related diseases, cedar-quince, cedar, hawthorn, and Japanese apple rusts are caused by fungi of the genus Gymnosporangium.
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Eastern Tent Caterpillar
The Eastern tent caterpillar has been observed in the United States since 1646.
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Fall Webworm
The fall webworm is a widely distributed native pest that appears from late summer through early fall. It feeds on many species of deciduous trees and shrubs.
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Fire Blight
Fire blight is a disease caused by the bacterium Erwinia amylovora. Twigs, branches, and leaders on trees and shrubs wilt…
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Hawthorn Lace Bug
Lace bugs are common pests of a variety of ornamental trees and shrubs.
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Hawthorn Leafminer
A moderately common pest problem observed on hawthorn trees in May and June is the hawthorn leafminer, Profenusa canadensis. The leafminer is the larval stage of a sawfly. The larvae live inside the leaf causing the leaf tips to turn brown. Leaves appear to be diseased or damaged by frost. However, frass and at certain times even the larvae can be seen between the upper and lower epidermis by holding the leaves up to the sun.
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Leafminer
A moderately common pest problem observed on hawthorn trees in May and June is the hawthorn leafminer, Profenusa canadensis. The…