Tag Archives: identification

Learning the moths: do it in pieces

6842 - Plagodis phlogosaria - Straight-lined Plagodis (2)
Straight-lined Plagodis, Plagodis phlogosaria

This weekend saw some exceptionally warm temperatures for this time of year, weather that I equate more with mid-July than with late April. It was glorious, sunny and warm, shorts-and-tee weather. Providing that you don’t get rain accompanying the warm weather (and even if you do, to some extent), these sorts of temperatures usually stimulate a huge flight of spring moths. If you put your sheet out on an unseasonably warm night, you can be sure that it will be crawling with critters.

7179 - Leptostales rubromarginaria - Dark-ribboned Wave
Dark-ribboned Wave, Leptostales rubromarginaria

As a result of these warm days, I’ve seen a dramatic increase in the diversity of species coming to my lights. Yesterday evening, for instance, I tallied probably upwards of 75 species. For someone just starting out in moths, such an evening can be incredibly intimidating. In my first spring, I knew virtually none of the species that were flying. Keener that I am, I really wanted to know what everything was. I took photos of every single moth I could separate as a unique species, and then spent all day trying to identify it all. I was way over my head, and even though I knew it, I plowed onward, determined to try to figure it all out.

10520 - Morrisonia evicta - Bicolored Woodgrain (2)
Bicolored Woodgrain, Morrisonia evicta

Well, it’s a great way to burn yourself out. If you live in a rural area with a diversity of natural habitats, you’re likely to see several hundred species over the course of a year. My number one tip to new moth’ers, based off of my recent experience – don’t try to learn it all in one year! It’s a great way to really turn yourself off this budding interest. As much as you itch to know what everything is, draw yourself a line and stick to it. Learn a subset this year. Then, next year, when the season rolls around again, you’ll have a good base of all the species you’re familiar with, onto which you can build the next subset of species.

7330 - Anticlea multiferata - Many-lined Carpet
Many-lined Carpet, Anticlea multiferata

I would strongly suggest beginning by learning the common things – the moths that you see dozens of on a given night. There aren’t usually too many of these species, perhaps two or three a week, so they’re easy to start with. This is really just common sense – by learning a small handful of species you can often easily skim over a quarter to half or more of the moths on your sheet. It eliminates a large portion of the “unknowns” from further consideration.

7895 - Clostera albosigma - Sigmoid Prominent
Sigmoid Prominent, Clostera albosigma

Where you go next is entirely according to your own preference. Perhaps in your first year you’d prefer to choose to concentrate on just the noctuids (primarily “chunky-bodied” moths) or the geometrids (the “flat” moths). Or maybe you’d like to focus on the brightly coloured and/or unusually-shaped species, the eye-catching things that will be easy to call to mind again next year when you start to work on the more subtle patterns. If you’ve got lots of time at your disposal, or you’re particularly good at picking up and learning identifications, you could even broaden your scope to include all of the macros, and next year tackle all of the micros.

6252 - Drepana bilineata - Two-lined Hooktip
Two-lined Hooktip, Drepana bilineata

The main thing is to break the effort into manageable pieces, and how you go about doing that is up to you. Taking photos of the moths, and then sitting down to identify the photos later, will help to solidify the identification in your mind, as will sorting through, labeling and organizing your files. It also helps provide a useful reference both for re-familiarizing yourself with the species the following year, and for comparing other photos you take to.

7871 - Deidamia inscripta - Lettered Sphinx
Lettered Sphinx, Deidamia inscripta

Personally, I think if I were starting from scratch again, it would be the unusual and eye-catching species that I would start with after I’d learned the common stuff. Not only are they easier to remember, and stand out on the sheet, but they’re also more interesting and help to stimulate and solidify your further interest in moths. To use a bird comparison, it’s a little like learning to identify the Scarlet Tanager, Eastern Bluebird and Indigo Bunting before you start looking at sparrows. Probably there are not many birders who can say that their interest in birds was piqued by a sparrow, but I suspect many were sparked by a Scarlet Tanager.

7939 - Furcula occidentalis - Western Furcula
Western Furcula, Furcula occidentalis

I’ve included in this post a variety of the more interesting or eye-catching moths that I caught yesterday evening, a taste of what’s flying this time of year, at least here in the northeast. And if you think this is great, just wait till June!

6240 - Euthyatira pudens - Dogwood Thyatirid
Dogwood Thyatirid, Euthyatira pudens

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

Learning to identify moths – part 1

Feeling a little overwhelmed by all the moths fluttering to your lights at night? It can seem a bit daunting at first. With upwards of 1000 species or more potentially being recorded in any given area (with higher numbers in the south or in habitat rich regions), your reservations are justified. Even the best birder, who can identify every single species of bird in North America, still only has some 700-odd species to contend with.

Still, there is some measure of satisfaction in being able to identify something, whether it be bird or moth or tree. There are a few species in any group that are easy to identify simply based on colour or pattern. Among North American birds, for example, nothing quite looks like a robin, with its gray back and orange-red belly. The same is true of moths, of course. Everybody knows the soft pale green of the Luna Moth, often seen floating through the room in sleep-aid medication commercials.

But it’s not just the smooth green that helps us identify the moth as a Luna. The other two characteristics we key in on are its size (quite large) and the two long tails streaming from its hindwings. Just like as with birds, size and shape are the most important characteristics to note when trying to identify a moth. Different groups of moths have different characteristics that set them apart. Once you’ve narrowed your moth down to a particular family or group, it’s much easier to then use the colours or pattern to make an identification.

There are two large, distinct groups of moths. The micromoths are 90% little wee guys (there are a couple of larger species that are classified in with them), and taxonomically make up the first half of a field guide. The macromoths are typically larger, and taxonomically come later in lists. It’s usually macromoths that are treated in most field guides. For instance, Covell, in the ex-Peterson guide, has just three and a half of 64 plates given over to micros. Most micros tend to be harder to identify than the macros, simply because their size makes it harder to pick out distinctive field marks.

However, one rarely chooses begin with the tough groups when learning to identify something new. Who starts with sparrows or warblers? Usually you begin with learning to identify the robin, Blue Jay, chickadee. The easy stuff. So let’s begin with the easy stuff. Here are some of the groups that I found the easiest to identify (at least to group) when I was starting out. By being able to recognize some common and characteristic groups, it makes it easier to quickly figure out where in the field guide you should be looking for the ID.

Groups ending in -idae represent the taxonomic level of family, while those ending in -inae are subfamilies.

Blinded Sphinx - Hodges#7824 (Paonias excaecatus) Lettered Sphinx Laurel Sphinx - Hodges#7809 (Sphinx kalmiae) Sphinx_drupiferarum
Sphingidae – the sphinx moths
The sphinxes are characterized by tapered, chunky abdomens and long, narrow wings. A few of these are daytime feeders, and when they’re hovering in front of a flower in a garden can often be confused for a small hummingbird. The ones with slightly less pointy wings often have eyespots on their hindwings, while the ones with pointy wings usually don’t.

Aug70a Aug79b White Underwing, Catocala relicta Woody Underwing
Noctuidae – Catacolinae – the underwings
These are mostly (though not all) large moths, with brightly-coloured hindwings. A few have dark hindwings, but all moths in this group share the characteristic broad wings that form a thick triangle when folded.

Aug72a Aug72b moth50 moth26
Pterophoridae – the plume moths
These are one of the most distinctive of families. Sometimes colloquially called the airplane moths, they have skinny little abdomens and long, narrow wings. They’re not very big, less than an inch and sometimes only half an inch in length.

Agreeable Tiger Moth Ruby Tiger Moth Harnessed Tiger Moth Isabella Moth (Wooly Bear Caterpillar) - Pyrrharctia isabella
Arctiidae – Arctiinae – the tiger moths
Arctiidae is a broad family that includes moths with a number of different appearances. However, the quintessential “tiger moth”, primarily those in the taxonomic tribe Arctiini, has a fuzzy thorax, a lightly furry abdomen (commonly orange or pink), longish triangular wings, and is often (though not always) brightly coloured. There are a couple other groups that are also fuzzy, but they tend to either be more stocky, all-over fuzzy, have broader wings, or fuzzy legs.

unknown76a Aug126 White-streaked Looper - Hodges#8953 (Plusia venusta) Aug127
Noctuidae – Plusiinae – the loopers
Superficially similar in shape to the tiger moths, the loopers tend to have a more strongly “tented” appearance, with wings that are broader at the outside tip than those of tiger moths. Loopers also usually have a hunch-backed appearance as their furry thorax forms shapely little tufts that make their head seem quite low. Many have a loopy little spot in the middle of their wing, as per the last photo.