Observation field or other data format for info about difficult-to-distinguish species that are not eligible for a species complex

I have a question about what the best way is to mark ID info for some difficult-to-distinguish species on iNat.

Bombus vosnesenskii and B. caliginosus are two very similar-appearing bumblebees in subgenus Pyrobombus whose ranges are overlapping. In some cases, a clear view of the underside or face or antennal dimensions can allow them to be distinguished from each other, but most photos don’t make this possible. Right now, they are usually only IDable to subgenus Pyrobombus, which has over 30 species in it.

A couple of us looked into whether it would make sense to have a species complex made, but they don’t meet iNat’s guidelines for that because this pair is not monophyletic (if I understand correctly, they are no more closely related to each other than they are to other species in subgenus Pyrobombus.)

So, it seems like under the current iNat guidelines, we’re stuck at Pyrobombus. But I would love to have some way to still mark the fact that it’s either Bombus vosnesenskii or B. caliginosus.

My ideas so far are to make an observation field or a tag. Is one of these the right way to go? Whatever we choose, I would love to have it be widely adopted, searchable, etc.


I use observation fields for likely Malacothamnus intermediates/hybrids. Seems like you could do similar for Bombus IDs. See: https://www.inaturalist.org/observation_fields/12106


Thank you, @keirmorse! I really like the structure of that example you gave. I had been imagining just dealing with those two species, but now I’m thinking I could make a field for all of Pyrobombus, with options corresponding to all the groups listed on BugGuide within that subgenus: https://bugguide.net/node/view/240705/tree

Voilà! The observation field: https://www.inaturalist.org/observation_fields/13422

Excellent! Hope it works well for you.