Ranges of Chyromyidae

Something iNat has been immensely useful for is helping me to determine the range of different species or groups of species. However, I recently learned about Chyromyidae, or Golden Flies, which seem to be an unfortunate exception. There are very few observations of flies within this family on iNat, and even fewer have reached research grade. Chyromyidae appears to be understudied and I have been struggling to find information elsewhere online regarding where certain species or genera within the family can be located. Would anyone here be able to give me some info on this or point me in the direction of somewhere that I can find it?


What part of the world are you interested in?

If you didn’t already see it, there seems to be a key to genus, presumably for N.America, here :

Unfortunately this is the case for many fly families!
We need more people to record flies ;)
This family just isn’t so common to find though I think.
At least in my 5000+ observations of Diptera so far in UK, I’ve only seen 1.
And when identifying N.American records at order I don´t recall coming across many.
I imagine some are misplaced by autosuggest as Lauxaniidae though…


I thought you had misspelled Chironomidae!! As well as the resources mentioned above, the Bugguide Family page is here - Family Chyromyidae - BugGuide.Net. It really doesn’t say much. You could also search Google Scholar for papers about the Family.
One of the things about flies is that finer identification is often based on small features that are hard to capture on pictures, and may often need a dissecting microscope to see. A number of the physically smaller insect groups are like that. Some are not even described to species. A possible career change for you? :grin:


Well, I’m always curious to learn as much as I can about things so any information would be nice, though I was the most interested in figuring out which genus/genera could be found in the US, particularly the midwest.

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This probably isn’t much use to you in that case, as I think they are all British:
Collin, J.E. 1933. Five new species of Diptera. Entomologist’s Monthly Magazine, 69: 272–275.

As someone has already said, there is plenty of more modern info available through Google Scholar.


According to the Manual of Nearctic Diptera:

The family consists of three genera, Chyromya, Gymnochiromyia, and Aphaniosoma, all of which occur in the Holarctic, Ethiopian, and Oriental-Papuan regions; 15 of about 40 known species occur in North America. The genus Chyromya has many synonyms and misspellings, most of which were summarized by Malloch (1914); Frey’s (1958) subgenus Somatiosoma (type, Chyromya (Somatiosoma) nitescens Frey, from the Cape Verde Islands) is probably an additional synonym. The three species of Chyromya that occur in the Nearctic region also occur in the Palaearctic region. About six Nearctic species of Gymnochiromyia, four of which are undescribed, are known in North America; the same is true of Aphaniosoma.


Also try the website Diptera.info. It has an extensive photo gallery and is frequented by international experts who are often willing to send pdfs.


Thank you for the help! So all three genera occur in North America? Do specific genera occur only in certain regions of North America or can any of them be found anywhere? If it’s the former, could you find the details of that?

Yes, the MND lists all three genera as “widespread”, so they can be found throughout the continent.

Hmm. I suspected range might be a way to help determine genus but it seems I was mistaken. Thank you for clarifying :)

Besides the MND, pp. 985-998, I think the most up-to-date resources we have on this family in North America are Malloch 1914 and Wheeler 1961.

They have some location data for species, but with the family being so infrequently collected, it’s hard to know where they truly don’t exist vs. where they just haven’t been recorded yet.


We need more people who can ID flies.


Also, yes.
(I editted that part of original comment)

For me, recording lead to identifying …but now each informs the other.

To obtain more obscure fly records, we need recorders who know what the more obscure flies look like, where to find them, how to record them, and have access to good equipment and/or desire to work with specimens.
OP also mentioned increasing numbers at Research Grade, but this could be a bit more complex in families like Chyromyidae with limited keys/undescribed species, or in geographies where the taxa aren’t well documented at present.

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