Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
White Mayfly -  Maccaffertium? - Ephoron album - female

White Mayfly - Maccaffertium? - Ephoron album - Female
Grand Junction, Mesa County, Colorado, USA
August 30, 2007

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White Mayfly -  Maccaffertium? - Ephoron album - female White Mayfly -  Maccaffertium? - Ephoron album - female

Moved from Mayflies.

White Fly
This is a female Ephoron, or "white fly" (family is Polymitarcyidae, and E. album is the only species listed for your state). In this interesting genus, the females do not have a final molt into the imago stage, but mate and oviposit as subimagines. The males do molt into imagines, and lose the middle caudal filament in the process. Another interesting trait of these mayflies is atrophied legs (all legs in females, but males have functional forelegs for grasping their mates); this causes the females to flop helplessly on the ground rather than being able to cling to vertical surfaces like most adult mayflies.

Thanks . . .
Lloyd: Thanks for the very help information! Best wishes, Scott

My pleasure, Scott.
This would be the first representative of this family/genus/species in the Guide. You can request a new guide page in the forum section entitled "Requests for Additional Guide Pages." Just to clarify my earlier comment about the two-tailed male imagoes, the middle filament is lost during transition from nymph to imago. This filament is thin and short in the male nymphs.

Thanks . . .
Thanks very much for your ID help! Best wishes, Scott

could this be smth in Oligoneuriidae?

However, I'm not sure what you meant by "smth?" I couldn't find anything by doing a bugguide search on either Oligoneuriidae or on something comparable to "smth."

I also did a Google search on Oligoneuriidae and found the following species found in the United States: Homoeoneuria alleni, Homoeoneuria ammophila, Homoeoneuria cahabensis, Homoeoneuria dolani, Lachlania dencyannae, and Lachlania saskatchewanensis.

Best wishes,

sorry, sorry to have confused you: smth = something,
the mayfly is distinct, so i'm sure your pic shows enough to ID the genus [perhaps even species] for an experienced eye -- mine is not

Ah ha!!
Well, you can tell that I'm still learning internet vocabulary! I am embarrassed to say how long it took me to understand that LOL does NOT mean "lots of luck!" :) Thanks again for the ID help! BW, Scott