Help with understanding Entomological terms

Hello, fellow iNaturalists! I recently found a book, Rindge, 1975. I want to use it to help me distinguish between members of the family Ennominae. However, I have hit a problem. While I took Anatomy in High School, I did not take Zoology, so I am having trouble understanding what is being said for the descriptions. Are there any iNaturalists out there who are Entomologists that can “translate” the Entomological vernacular, or at least help me understand it better? Here are the pages from the book:

I appreciate all of the help in advance!


Bugguide does have a glossary, although it’s got a lot more entries than it does info at the moment.

Arnett’s Handbook of North American Insects has a rather comprehensive glossary as well, but it’s not selling cheaply these days, apparently.


Here’re two online introductory courses for entomology:

And this classic entomological dictionary is freely available:
(Jardine’s Dictionary of entomology)


Which terms in particular are you referring to?

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When I have trouble with entomological terms, I usually ask Google to “define X” and if that doesnt work, I search the term on Google Images. I’ve been doing this since day 1, and it’s served me well.


I am not sure when the book refers to “Vein M2”, " R1+2 (I just realized that the editor does not contain superscripts or subscripts!), or cells Cu2. It sounds like the book is going into very fine detail about the different veins and intermediate lines on the wings. A figure pointing to these structures would be very helpful for someone who does not know anything about them.

Moths can have their own terminology. A basic very useful glossary with images (e.g. all the veins numbered on a forewing image) is from the Pacific Northwest Moths site:


Thanks @krancmm ! I will check it out! Also, do you suggest looking at the wiki about Noctuid moth identifying features by @mamestraconfigurata?

Since you’re now looking within the Geometridae family, some of ID features of Noctuids don’t “translate” perfectly. However no good info goes to waste. That’s a good primer and if you keep moth-ing you’ll invariably have a Noctuid or ten.


So I’m just an enthusiast, but this is what I have learnt.

  1. M2, Cu2 etc. are the names that are given to the veins that are present in the butterfly’s wings.
  2. The above system (Comstock system) is not the only vein naming system. There is also a Numerical Notation system.
  3. There seems to be a general venation pattern for Lepidoptera, and different families can be distinguished by paying attention to certain modifications within that general venation pattern (amongst more obvious morphological differences).
  4. Vein names are important as they serve as precise locational cues to look for distinguishing patterns between similar looking species.

A more “for the layman” reference on Lepidoptera wing venation would be (


How do you find these things? It takes me several hours just to find a reliable source on Google that is not Wikipedia. I am not sure if I would have found the Rindge, 1975 book without @treichard’s help. I guess it is just the right wording and persistence.

Just google insect venation or vein R1+2 in insects.

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I’ve often thought myself that a guide or website that just showed insect wing venations would be a very useful thing, given how many groups have ID’s based on them.


I second @krancmm’s suggestion. It’s a good glossary. Part of the problem with Entomological terms is that each group may have it’s own specialised terms. Odonata has a different nomenclature for wing veins than Lepidoptera (there are some similarities). There are a lot of good suggestions above - I would only add “An introduction to the study of insects” by Borror and deLong. The book does cost a lot, but I believe it can be downloaded free. I don’t know how well it works (or if it’s legal!), but it’s a good resource. I prefer books to downloads, but they do help. I’d also recommend William T. Forbes Lepidoptera of New York and Neighbouring States: Noctuidae. Memoir 329 Cornell University Agricultural Experimental Station (1954). I was able to download a copy, and it has basic terms at the beginning. If you use it for a key or for descriptions use Ctrl F and search for species names in the text - most of the Genera have been changed.
My stuff (which I haven’t updated in a while!) is more of a simple visual reference. I hope folks find it useful, but it is by no means comprehensive.


Heh. Welcome to entomology. Where diversity goes to extremes, terminology included. I picked up a copy of The Torre-Bueno Glossary of Entomology back in grad school. You want to buy it, cheap? It’ll get you going in the right direction but even then, you’ll often need to chase down other references.


I have been reading that blog even before that article was up. It is primarily focused on Singaporean butterflies but its a very good blog and lots of fun and informative reads. It’s also useful to me because Hong Kong also has many mutual species and I learn more about them there.

To add to point 4 of my previous reply, its like using the venation system (eg. “missing white spot near the base of space M2…”) vs. using a photo to point to where the features are (points “there is a white spot missing here…”). Technical terms are helpful in that sense. I certainly have not even struck the iceberg tip on that aspect.


All 4 volumes of Forbes’ Lepidoptera of New York and Neighboring States are useful for moth terminology.

Part 1

Part 2 covers the Geometridae and includes vein diagrams for that family.


Thanks! I just found free pdf online. It is a bit long and general, but it describes the characteristics of Lepidoptera in more simple terms, as well as the characteristics of Superfamilies, Families, Subfamilies, and Tribes of Lepidoptera in Canada - I hope other people find this useful as I have.

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Must be a newer edition. Mine is Borror, Triplehorn, and Johnson. Useful for getting to family, not so much beyond that.