False Hemlock Looper

2017 February 15

This moth was hanging around our porch light on August 8, 2016. It had a fairly striking pattern of wavy dark lines across a light gray background.


It also had quite feathery antennae (so was probably a male), and small, but distinctive, yellow-orange spots on top of his head and on each shoulder.


When searching for it, the first reasonably close match was the Phantom Hemlock Looper, Nepytia phantasmaria. And yet, in addition to not looking quite right, the notes on BugGuide said that those (a) normally didn’t emerge as adults until September, and (b) are reported from further west in any case.

So, I checked its close relatives, and found a better match with the False Hemlock Looper, Nepytia canosaria. These not only live further east (including in Michigan), but also fly in mid-summer, like this one. There is considerable variation in how dark they are, but this specimen fits right in with the ones near the lighter end of the range.

So anyway, the caterpillars are green inchworms with distinct white lines running down their sides, which is fairly good camouflage on the needles of the coniferous trees (firs, hemlocks, and spruces) that the caterpillars eat. Given that the caterpillars apparently do eat hemlock, I don’t know what makes it a “false” hemlock looper, aside from its relatives probably getting the name first. Personally, I think I would have opted for something like “Northeastern Hemlock Looper”, or maybe “Summer Hemlock Looper”, or some other distinguishing trait, rather than just labeling it as some kind of fake.

One Response
  1. February 18, 2017

    Really. Calling it a False Hemlock Looper casts aspersions on its character.

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