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European elm flea weevil

Quick facts about European elm flea weevil

  • The European elm flea weevil (Orchestes alni) is an invasive insect, common throughout Europe and first found in the U.S. in 1982.  
  • It was not found in the Midwest until 2003, and in Minnesota until 2007.
  • This weevil feeds on Siberian elm, Chinese elm and hybrids with Asian parentage.  
  • It rarely feeds on American elm.
  • The feeding damage only affects the appearance of the tree.
A red weevil on the under side of a green leaf with red veins
Adult elm flea weevil

How to identify them

The adult elm flea weevil is small, 1/10 - 1/8 inch long.  

It is reddish brown with black spots or dark brown to black, with a long snout and large back legs which allow it to jump.  

Life cycle

European elm flea weevils live through the winter as adults and in the spring, move to the elm tree. Soon after, the adults lay eggs along the edges of the veins.  

When the larvae hatch, they feed as leafminers inside the leaves. They move to the tip of the leaves where they create blotch mines.  

The larvae feed for a few weeks and then transform into pupae.  

Adults emerge later in the summer and feed until fall.

Browning at the tip of a green leaf
Blotch mines at the tip of leaves
Green leaves with brown tips and brown holes
Elm flea weevil feeding
Leaves with several brownish holes
Elm flea weevil feeding damage

Damage caused by elm flea weevil

European elm flea weevil does not cause serious damage to elm.

In case of heavy feeding on recent transplants or stressed trees, severe defoliation can occur. This might weaken the elm and make it an easy target for other problems.

  • The weevil feeds on the underside of leaves, feeding on the lower surface of leaves but not chewing through.  
  • A thin, opaque layer of leaf tissue remains.
  • Eventually, this chewed area dries up and fall out.  

The damage might look similar to injury caused by elm leaf beetle. But, elm leaf beetle feeding creates small oval holes in the leaves with the edge of the holes still green.

How to protect your garden from elm flea weevil

Treatment for european elm flea weevil is unnecessary.

If treatment is desired, apply a systemic pesticide like imidacloprid in early spring to control this weevil.

CAUTION: Mention of a pesticide or use of a pesticide label is for educational purposes only. Always follow the pesticide label directions attached to the pesticide container you are using. Remember, the label is the law.

Jeffrey Hahn, Extension entomologist

Reviewed in 2018

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