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

Upcoming Events

Information about the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Baetidae - Callibaetis fluctuans

Baetidae - Callibaetis fluctuans
Marlton, Burlington County, New Jersey, USA
May 7, 2008
Came to the light at night. Is this maybe Callibaetis? But also looks similar to this one Any ideas?

Images of this individual: tag all
Baetidae - Callibaetis fluctuans Baetidae - Callibaetis fluctuans

Callibaetis fluctuans
Hi John-

I believe this male subimago to be Callibaetis fluctuans.


Moved from Mayflies.

Most, but not all Callibaetis display a distinct speckled pattern on their wings and fine spots on their abdomen. In addition, the pattern of cross-veins seems too sparse for this to be that genus, although I wouldn't completely rule it out because the costal angulation of the minute hindwing is blunt or obtuse. Size might be helpful, if you can remember the size with some degree of accuracy.

Many (most?) baetids are very difficult to take genus with a photo, let alone to species. The species you found on Troutnut is common, transcontinental, and is one of the earliest mayflies to emerge in the East. Despite that, Jason probably keyed it out just to be sure. Even though tricaudatus is often multi-brooded (more than one generation per year), I really doubt that's what your specimen is. Notice the sharp costal angulation on the hindwing in Jason's specimen.

How do you feel about Cloeon dipterum for this one? Look pretty close?

Yes, except...
that I'm pretty sure that's a tiny hindwing at the base of the forewing. :)

Added another to show base better. Looks like you are correct?

it shows a tiny hindwing with a blunt costal angulation. That might help to get this one to genus at some point. I did find three or four others that probably are C. dipterum.

I appreciate all of the help (and the great information). It really is nice to learn about these guys. Unfortunately size is unknown. I got the one shot and it was gone, and I would rather not guess and further confuse the issue.

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