Letter to the Editor: Save the Blue Spruces!

Los Alamos

I’ve noticed that many Blue Spruce trees in White Rock are being eaten, and killed, by caterpillars. Perhaps same is occurring to other trees, and perhaps in Los Alamos too.

Per the LA County Extension website (http://losalamosextension.nmsu.edu/problems.html), under “Plant Problems of Los Alamos” à”Conifer Pests” à”Douglas Fir Tussock Moth” link


Caterpillars of the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), chew the needles of spruces, Douglas fir and true firs. During outbreaks they may cause extensive defoliation, with injury typically first concentrated at the top of the tree. Older caterpillars may rapidly defoliate a tree and tops may be killed, sometimes after only a single season of severe injury. Following repeated attacks over several seasons whole trees may die or be weakened to the point of inviting fatal attacks by bark beetles.

If your Blue Spruce is turning brown, even if only at the very top, it probably has these caterpillars (even if you cannot see them), or had them and now has the more mature forms of the moth. Contact a tree expert or sprayer about whether your tree is savable, when to treat (now and/or next spring) and with what.

I’ve heard good things about both companies listed under “Tree Sprayers” in the LA 2014 Names and Numbers Directory. There are probably others. I don’t care WHOM you use, but please treat your trees as necessary.

IMPORTANT: As these caterpillars can cause painful skin reactions, no one should touch them.


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