Subject:  Antlion maybe
Geographic location of the bug:  west Delores River, fir tree trunk near flooded river
Date: 07/09/2019
Time: 12:34 PM EDT
Your letter to the bugman:  I would like an identification on what is probably a mature ant lion of south western Colorado at a picnic area 10 feet from the stream.
How you want your letter signed:  Joanne


Dear Joanne,
This is not an Antlion.  It is a Giant Stonefly in the genus
Pteronarcys, commonly called a Salmonfly.  Since the larvae are aquatic, Stoneflies are usually found quite close to water.  According FinsAndFeathersOnline:  “25%, maybe more of our ramblings as anglers is about the mythical, 3-inch enchanting salmon fly. Especially around this time of year! It’s hard to avoid the fly fishing chatter of anglers exploiting the famed long aquatic insect. Fishing this hatch gets our blood bumping and longing for the story to our arsenal of impressive fishing stories.  Salmonflies are very large stone flies! Montana has three salmonfly species: the most common being the giant salmonfly (Pteronarcys californic. The other two are the American salmonfly (Pteronarcys dorsat), and the least salmonfly (Pteronarcella badia). The least salmonfly is a little bit smaller than the giant and the American. They usually get up to 2 inches, and are in their nymph stage for about 2 years. The American and giant have the bright orange or red band behind their head and the underside of their abdomen.”

Thank you very much.  And so quick too. I see a almost perfect match in my Kaufman Book but didn’t know where to look.  Joanne

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BugMan aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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