Learning to identify moths – part 2

Eastern Tent Caterpillar Moth, Malacosoma americanum – often one of the most common moths at your sheet during its flight period

Even with learning the different groups of moths, however, it is still easy for one to feel in over their head. As with birds and other organisms, there are two ways of deveoping some confidence and developing a base from which you can build the rest of the trickier identifications. The first is to learn to recognize the common stuff. Like birds in migration, moths have windows of time where they will be quite common, and outside of that you won’t see them much, if at all. Figure out what seems to be common during any given time frame. Some species of moth are so common during their flight windows that every third or fourth moth on your sheet might be of that species. If there’s lots of something, chances are the next thing that looks something like that is probably it as well. Also, if you get to know your common species, then when something different appears, you’ll be more likely to recognize it as a different species. You can save a lot of time by not having to identify every single moth at your light.

Hologram Moth, Diachrysia balluca, a more northern species

The second is to learn to identify the very unique or striking species. It can’t be underestimated how satisfying, and what a boost to the confidence, it is to know the name of something as soon as it lands on the sheet, without having to go look it up. For many species, this can be achieved through spending some time with your field guide, or browsing through the plates at Moth Photographers Group. For instance, when I discovered this moth in my trap one morning, I didn’t need to reach for my guide, I knew immediately that it was a Hologram Moth, Diachrysia balluca. (I didn’t know the scientific name at the time, which I personally find hard to store in my memory, but for species with a recognized common name, usually that’s sufficient for identification.)

9286 - Harrisimemna trisignata - Harris's Three-Spot
Harris’s Three-Spot, Harrisimemna trisignata

The other thing I should mention is that quite often, because these unique species tend to be easy to identify and remember, you come away from your guide studies with a bit of anticipation to seeing it. So when the moth does eventually turn up, not only is there satisfaction in being able to name it, but also excitement that this long-awaited species has appeared. So it was for me with the Hologram Moth, or the above, a Harris’s Three-Spot, Harrisimemna trisignata. Eventually, once you’ve come to know and be able to identify most of the regulars at your light, the stuff you still haven’t seen, even the little brown jobs, will acquire this sense of excitement – but it will probably take a number of years of mothing to get you to that point.

Here are a few other easy-to-identify species, some of them fairly common, that you should be able to easily pick out.

Dogwood Thyatirid
Dogwood Thyatirid, Euthyatira pudens

Ailanthus Webworm, Atteva punctella
Ailanthus Webworm, Atteva punctella

Silver-spotted Tiger Moth
Silver-spotted Tiger Moth, Lophocampa argentata, a western species

Black-rimmed Prominent
Black-rimmed Prominent, Pheosia rimosa

Chickweed Geometer
Chickweed Geometer, Haematopis grataria

The Herald, Scoliopteryx libatrix

Horrid Zale
Horrid Zale, Zale horrida, an eastern species

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