Extension > Garden > Diagnose a problem > What's wrong with my plant? > Deciduous Trees > Elm > Sawdust at base of trunk
Elm > Trunk/Branches > Sawdust at base of trunk
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Carpenter ants
Componotus spp.
- Excavate smooth tunnels in moist or 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 ¼- ½ inch long and queens over ½ inch in length
- More information on Carpenter ants
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Carpenterworms
Prionoxystus robiniae
- Exit holes in wood are round and large, about 1/2 inches
- 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
