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Cosmopterix pulchrimella - Cosmopterix

Cosmopterix pulchrimella - Cosmopterix
Chicago Botanic Garden, Cook County, Illinois, USA
May 30, 2016
Size: 5 mm long
Collected as larva in Carex hyalinolepis in March. Pupated in leaf mine and emerged May 30th.

Images of this individual: tag all
Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix Cosmopterix pulchrimella - Cosmopterix


Moved tentatively - everything looks good for magophila...
except the antennae around the midpoint, but I suspect that's just a product of the flash. Moved from Cosmopterix.

Cosmopterix magophila
I noticed that in Koster (2010) that the antennae of magophila are described as having five white segments at the appex. This individual has brown segments at the appex?

Koster states that the apex of C. magophila has 8 white segments
However, the illustration Koster does not match perfectly (note the small black apial segment in the illustration and short white penultimate section). I have noticed a couple discrepancies like this in the past with Koster. Hodges' 1978 MONA fascicle also mentions magophila having a small black apical segment.

Do you have any other pictures of this specimen? Did you collect it?

I have at least five pinned specimens of this species. I also have several other pictures of the individual shown. I will attach one or two additional to the site.


If you have a microscope available, can you take a photo of the
apex of the antennae and the basal pair of silver spots? I'm still leaning magophila on this one, but would like confirmation. Were the other specimens reared from the same individual plant?

Larval plant
Yes, all specimens were from the same larval plants. I found, perhaps a hundred mines in February on those sedges with sometimes two to three mines per plant. Carex hyalinolepis is clonal so occurs in large patches and is somewhat evergreen through the winter. Larva were present in February and pupated in March.

Cosmopterix antennae

I did the best I could and have attached both an antenna apex and basal spots image.

Ran your specimen through Koster's key (again)
Still coming up with magophila. I'm not a fan of his key though. For example:

Forewing with outer dorsal spot opposite outer costal spot or nearly so ...................................................... 84
- Forewing with outer dorsal spot closer to base than outer costal spot ...................................................... 93

Seems kinda arbitrary to me. The key is chock-full of calls like that. It's frustrating.

It's especially frustrating when his key doesn't match his figures. Running your specimen through the MONA key by Hodges (1978) points to damnosa, but Koster's description doesn't match Hodges'.

I think it's best to leave this one at the genus level until they can be dissected. I can only imagine how many images I've keyed out here on BugGuide using these keys only now to find out how unreliable they are.


I attached two images of genitalia. I am just learning to do these so they may not be useful for ID. I could not find any images to compare to.



May not be C. pulchrimella
C. pulchrimella's transverse fascia is supposed to be bordered on both sides by metallic fasciae rather than metallic spots.

I don't know if pulchrimella's host plants include Carex spp., but C. clemensella's do, for what it's worth.

Moved from ID Request.

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