Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Elm > Leaves are curled or twisted or distorted
Elm > Leaves > Leaves are curled or twisted or distorted
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Woolly Elm Aphid
Eriosoma americanum, E.lanigerium and E. rileyi
- Severe infestation can twist and curl leaves; leaves can yellow; branches can dieback
- Colonies on wood are covered by a white waxy or cottony material
- Produces honeydew from the aphid feeding, look for sooty mold on leaf surfaces or twigs
- Adults are dark colored (reddish, brown, purplish), tiny size (1/16 to 5/32 inch)
- Preferred hosts are American and slippery elm
- More information on Woolly Elm Aphid
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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
