Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes


Miner on bulrush - Elachista

Miner on bulrush - Elachista
Dickinson County, Iowa, USA
September 10, 2016
On what I believe to be a rush, Juncus sp., at the edge of a wetland. Note the darkened larva/pupa in center of image and the similarly sized pale larva on the right side of the image.
UPDATE: Michael Palmer suggests the host is Schoenoplectus/Scirpus (Cyperaceae), not Juncus, and I am inclined to wetland plant ID needs some work :)
UPDATE, Feb 2017: Regarding the host plant, John Pearson writes, "Either Hardstem Bulrush (Schoenoplectus acutus) or Softstem Bulrush (Schoenoplectus tabernaemontani). In fact, I once heard that the two might have taxonomically merged as the same species." Thanks, John!

Images of this individual: tag all
Miner on bulrush - Elachista Miner on bulrush - Elachista Miner on bulrush - Elachista

John, would it be possible for you to add closer views of the larvae in this photo? I found the Acalyptris on Schoenoplectus in Michigan this summer and the mines look very similar. The larvae were yellow like the one at the right edge of the photo, and I'm wondering if the dark one might be dead/dying. I'd be interested to see any other shots you have might have.

Slightly better shot of the yellow ones

Best I can do and that's the highest resolution :/

While we're on the subject of larvae that feed in Cyperaceae, this seems like pretty distinctive sign (and a pretty distinctive larva) and I wonder if you have run into it before:

Moved from Acalyptris.

I see what you mean, Erik. Also the margins of the mine are rather irregular for an Acalyptris, and if that thin brown line in the above photo is the beginning of the mine, we should be seeing the eggshell if it were a nepticulid. Naturally, there is no Elachista known on Schoenoplectus.

Moved from Unidentified Signs on Twigs, Stems, and Stemlike Structures.

There is a complex of Acalyptris species on various sedges, and a lot more work needs to be done on them. A species similar to A. thoracealbella has been reared from Schoenoplectus americanus in Maryland.

Acalyptris or Elachista?
Looking at the photo of the larva I am not so sure it is a nepticulid, it looks more like an Elachista to me. The dark colour and distinct segmental divisions are more like that.

Thanks so much, Charley! :-)
I'll have to keep an eye out for this in the New Year.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.