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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Oak > Sawdust at base of trunk

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Oak > Trunk/Branches > Sawdust at base of trunk

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  • Image: Carpenter ants 1
  • Image: Carpenter ants 2
  • Image: Carpenter ants 3

Carpenter ants
Componotus spp.

  • Excavate smooth tunnels in dead, decayed wood, creating coarse sawdust around openings
  • Galleries can weaken branches and cause them to break
  • Black or black and red; workers range in size from 3/16 to 3/8 inch long and queens up to ½ inch in length
  • More information on Carpenter ants
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  • Image: Carpenterworms 1
  • Image: Carpenterworms 2
  • Image: Carpenterworms 3

Prionoxystus robiniae

  • Exit holes in wood are round and large, about 1/2 inch
  • Galleries start in sapwood, eventually entering heartwood
  • Large amount of sawdust in piles present at trunk base
  • Stout bodied moths, black and light gray mottled forewings as large as 2 1/2 to 3 inches
  • Yellowish white caterpillars with brown heads; 2 to 3 inches long
  • More information on Carpenterworms

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