Detailed profiles of common plant diseases, pests, nutrient deficiencies and environmental problems.
Corn eyespot is a residue-borne fungal leaf disease caused by Kabatiella zeae, also known by its current name Aureobasidium zeae. It produces small, translucent…
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European spruce bark beetle (Ips typographus) is a serious bark-boring pest of spruce, especially Norway spruce, that breeds beneath the bark of stressed, recently…
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Impatiens necrotic spot virus (INSV) is a serious, thrips-transmitted disease of greenhouse and garden ornamentals in the United States. Symptoms vary widely by host…
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Cottony cushion scale, Icerya purchasi, is a sap-sucking insect that attacks citrus and many woody ornamentals in the United States. Females are recognized by…
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Ash dieback is a destructive fungal disease of ash caused by Hymenoscyphus fraxineus, formerly associated with the names Chalara fraxinea and Hymenoscyphus pseudoalbidus. Typical…
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The mealy plum aphid, Hyalopterus pruni, is a small sap-feeding pest of plum and other Prunus trees. Pale green aphids covered in whitish wax…
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Hyaloperonospora parasitica is an oomycete associated with downy mildew on selected plants in the mustard family, including shepherd’s purse and some ornamental brassicas. Identification…
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European apple sawfly, Hoplocampa testudinea, is an introduced sawfly pest of apple in parts of the eastern United States. Adults fly and lay eggs…
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The black plum sawfly, Hoplocampa minuta, is a specialized fruit-damaging sawfly associated mainly with European plum and myrobalan plum. Adults appear around plum bloom,…
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The yellow plum sawfly, Hoplocampa flava, is a fruit-damaging sawfly associated primarily with European plum and myrobalan plum. Adults appear around plum bloom, and…
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Beet cyst nematode is a microscopic, soil-borne plant parasite that attacks sugar beets, table beets, spinach, and many Brassica crops. Feeding on roots disrupts…
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Heterobasidion root disease—historically called annosus root rot or annosus root and butt rot—is a destructive fungal disease of conifers. It often remains hidden until…
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