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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous > Lilac > Holes in stems

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Lilac > Stems/branches > Holes in stems

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  • lilacborer1
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Lilac Borer (also known as ash borer)
Podosesia syringae

  • Wilted or dead stems
  • Base of stem swollen with ¼ inch exit holes
  • Sap, sawdust and frass exuding from holes
  • Reddish-brown pupa cases sometimes found protruding from exit holes
  • Larvae are 1' long; creamy white with light brown head
  • Adult is a clear wing moth that resembles paper wasp; smoky brown forewing, hindwing is clear with brown edge.
  • More information on Lilac borer

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