Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Elm > Unusual projections on leaves
Elm > Leaves > Unusual projections on leaves
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Elm finger gall
Eriophyes ulmi
- Fingerlike galls are erect ½ inch from the leaf surface
- Gall on upper side of leaf, potentially curled and deformed
- More information on Elm finger gall
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Elm cockscomb gall aphid
Colopha ulmicola and C. graminis
- Aphid induces a 1 inch long by ¼ inch high wrinkled swelling on the leaf surface, irregular like a rooster’s comb
- Reddish at first but turning brown as the season progresses
- Found on American and red elm
- More information on Leaf galls
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Elm casebearer
Coleophora ulmifoliella
- Larvae mine angular spots between leaf veins causing brown areas that can coalesce to complete browning in high infestations
- Create cigar-shaped cases out of leaf tissue and silk that hang from leaf underside
- Preferred hosts are American, red, and slippery elm
- More information on Elm casebearer
