What do we do with moth "complexes" regarding ID?

In moth identification, there are a number of Genera that have 'species complexes" (i.e. https://bugguide.net/index.php?q=search&keys=xestia+complex&search=Search). The moths, occasionally three or four in a complex, cannot be told apart without dissection and genital comparison. Since most of our ID’s are made from photographs, what would be the best way of identifying these moths that would satisfy most experts? Should they be labelled as simply Genera with ‘as good as it gets’ label, or is there some other way of dealing with these complexes?


This problem is common to all groups of small organisms, and the general solution is to ID to the lowest possible rank and include in your comments or in a holding bin field what the possibilities that you cannot rule out are. You can also now create species complexes and use them as if they were a regular ID.


Is there a specific taxonomic definition of “species complex” that should be used when making a new “taxon” on iNaturalist, or can it be used for any tricky species group (like a slash or sp. on eBird)?

Edit: Might have been smart to look it up. Here is the help page section on it: https://www.inaturalist.org/pages/curator+guide#complexes
So yeah there is a pretty specific definition, which may not cover many examples of species groups that can’t be identified from photos.

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Is there a way to see what species complex have been created as regular IDs? Will they pop up under the species suggestions?

I just tried it for Xanthotype (2 closely related species that require dissection to ID), and the individual species (urticaria & sospeta) came up, but not the two together as a complex. Has it simply not been created yet?

It’s a new rank on iNat, so there are only a few so far:



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Thank you all for the help. I’ll follow the suggestions. I’ve come across a number in the Noctuids, some of which are routinely caught, so I’ll probably make some new ones.

Here’s one way they were dealt with in the past:


Could someone walk me through steps of making a complex from Xestia c-nigrum/Xestia dolosa? I’ve tried a number of times with no success. Reference is https://bugguide.net/node/view/30522

My approach would be:

After this, when someone wants to use the complex as an ID, they’ll need to type in the species for which it was named, and choose the complex instead of the species from the list. (Or you could create a unique “common name” for the complex for lookup purposes.)


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