Answer: Did you check for mites or spruce needle miners? Needle cast is a result of needle miner feeding and you can detect them by inspecting the shed needles and looking for tiny openings at the base. Spider mites leave a tell tale webbing between the needles. There are controls for each of these insect pests but of course controlling them now will not replace the lost needles. For even more information you can contact your local cooperative extension office. Best wishes with your spruce tree!
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