Gardening question: What are the most common pests, specifically worms, that infest Cedar trees? ?

Question

I am currently battling weird worms on my Cedar tree; they have cocoon like wraps from their mid-section to end. The worms look like mealy (?) worms, with segmented bodies.

THEY WILL NOT DIE FROM NORMAL INSECTICIDE! They seem to feed on bark, not on the green "leaves" or "fronds" or whatever you call it on a Cedar.

Thanks!

Answer 1

boy, wish we had a picture.  First thought was bagworm http://www.pestproducts.com/bag-worm.htm

Then thought some type of flathead wood borer larvae but there's no cocoon on the butt: http://www.ext.vt.edu/departments/entomo...

Final thought was some type of scale.  Tiny. They indeed are hard to kill.  It can be done but first we have to know if that's the problem and then timing is critical for control.  

You didn't mention their size and if you are finding holes, if you can pick them off, do they scurry about.   What is the damage?  

Answer 2

Cedar is famous for it's ability to discourage insects and about the only pest that will bother a cedar tree is the Cypress Beetle.  These bore into and feed on the bark, and certainly don't match your description.  It is possible these critters aren't the cause of your tree fading.  Why don't you take one of them and a sample limb to a garden store or nursery.  They can probably help you out.