Hemlock Tree – White Things At Base

hemlock adelgid

Q: We have a ten-year-old hemlock tree. We noticed a few tiny white things at the base of the needles on some branches but not that many. I’m worried these could be hemlock woolly adelgid. The temperature got down to 1° F this past Christmas eve. Would that have killed any insects on the tree?

A: Like all living things, hemlock woolly adelgid can be killed by cold temperatures. A high percentage of these sucking insects will die when temperatures drop to -4° F, but some will survive. These individuals will be the basis of a big population surge in spring. I have details on how to control adelgids here.

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