Difficult Identification

“I found this neat butterfly, what is it?” As you might imagine I hear that question a lot and most of the time I can give a straightforward answer based on a photograph or basic description. Other times, it isn’t so easy. Many species of butterflies are pretty easy to identify. Even species that mimic each other usually have some telling marks or coloration to help separate them out from a mimicry complex.

But then, there are the Skippers. Many species of skippers are incredibly difficult to identify because their identifying marks are variable based on sex, season or location and also because some species so closely resemble each other that those variations are very minor. Especially difficult is the genus Erynnis, commonly known as the Duskywings.

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A few days ago I spotted a lovely little Duskywing skipper in the forest and collected her to get some photographs and see if I could make an identification. That hasn’t been the easiest. Instead of being able to figure the identification out right off I have instead had to narrow down based on what I know and can observe.

First, I can narrow down the suspects based on location. There are 17 species of Duskywing found in North America, 8 of which have been reported in Florida and 4 of those have been reported in Hillsborough County. New records are being added all the time, but for now we will just narrow down to the 4 reported species found in the county. Now I can further narrow the list to 2 species based on observations of patterns and spots. Both remaining species are incredibly similar in appearance, are found in the late spring and have been reported in Hillsborough County.

I’m pretty sure that this lovely little butterfly is a female Horace’s Duskywing (Erynnis horatius) but it could also be the closely related Juvenal’s Duskywing (Erynnis juvenalis). I may never know what species this butterfly is for sure, but it has been a fun bit of investigation.