Tiger moth – Grammia

2009 October 17

We had a serious snowfall last week which really knocked out the active insects, so I guess it’s time to look at some of the insects from earlier this summer. This moth is one that came to our porch light in June[1]. There were several others just like it, so they are obviously pretty common locally.

They are pretty large moths, and in daylight they are practically comatose, so it was easy to use my thumb to spread the forewing so we could see a hindwing:


And, as it turns out, once the wing was spread it would keep it like that for a while, so we can also see it with both wings spread:


It would also lay on its back for a while. Overall, it was very cooperative:


And, as is common for moths, it had long, feathery antennae:


This looks like one of the tiger moths in the genus Grammia, which have that characteristic black forewings with white stripes, and orange hindwings with black spots. As far as which species it is, I’m not so sure. I thought at first that maybe it was a Virgin Tiger Moth, Grammia virgo, but it could just as easily be the Parthenese Tiger Moth, Grammia parthenese. The striping patterns and hindwing spots don’t seem to match any of the BugGuide pictures perfectly, so I guess we’ll have to leave it at that.

Update: After capturing another one in 2014 and going back through BugGuide, I see that they now have pictures of the Little Virgin Tiger Moth, Grammia virguncula, which in at least some pictures is a much better match than I was able to find back in 2009.

Like the other tiger moths, Grammia tiger moths have woolly caterpillars, and evidently some of them look like this one that I photographed previously. They generally overwinter as caterpillars, although that probably depends on the species.

[1] When we were getting ready for our insect presentation at the library on June 22, we decided to leave the porch light turned on the night before, and go out around midnight to catch what was there and pop them into a screen cage to take in. We found a lot of good moths, there are several more to come. This one was one of the more common species.

2 Responses
  1. Daniella permalink
    December 4, 2011

    what do they eat? do they drink water? how can yu tell the diffrence between a female and a male?

  2. December 5, 2011

    The caterpillars of tiger moths tend to eat grass and other plants that are likely to grow in lawns. The adults evidently eat nectar (although some some species may have short-lived adults that don’t eat at all). I expect that the water they drink is mostly dew from plants.

    Male moths tend to have feathery antennae (like this one), while females usually have threadlike antennae with very little feathering.

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