On May 3 I met Jon Nikkila at Box Elder SWMA in Lincoln county for a second look at this WMA. Our first visit was very early (April 11) and we looked almost exclusively for Giant Yucca Skipper tents (of which we found two) along with one Olympia Marblewing. This trip the main target species was the Fulvia Checkerspot. We were unable to locate that butterfly but should have other opportunities for that species through June. However our visit was not in vain. With a side trip to Jeffrey Canyon SWMA 10 miles to the east six more species were added to the 2020 Big Year list bringing the tyd total to 19 species.
Our best find of the day were Silvery Blues (Glaucopsyche lygdamus) which were almost common at Box Elder. This butterfly can only be found for a couple of weeks in the spring. In Nebraska it had only been found in the panhandle until the 1980s when it was discovered in the loess hills of southwest Nebraska. Subsequent investigations in that area have proved fruitful. In that portion of the state (and at Box Elder) the larval hostplant is slender milkvetch (Astragalus gracilis).
Our sightings for the day were (* denotes first Big Year sighting) Roadside Skipper (Amblyscirtes vialis), *Black Swallowtail (Papilio polyxenes), Tiger Swallowtail (Papilio glaucus), Olympia Marble (Euchloe olympia), *Clouded Sulfur (Colias philodice), *Gray Hairstreak (Strymon melinus), *Silvery Blue (Glaucopsyche lygdamus), *Variegated Fritillary (Euptoieta claudia), *Gorgone Checkerspot (Chlosyne gorgone), Red Admiral (Vanessa atalanta) and Painted Lady (Vanessa cardui).
Silvery Blue (Glaucopsyche lygdamus) 
Slender Milkvetch (Astragalus gracilis) – Larval hostplant for Silvery Blues 
Distribution of Silvery Blue in Nebraska 
Gorgone Checkerspot (Chlosyne gorgone)
Something else that caught our eye was three dung beetles, each attempting to wrest control of a dung ball from the other two. That picture begs a caption. If you think of one or have any questions or observations to share let us know at NebraskaButterflies@gmail.com
Dung beetles competing for a dung ball
All in all an enjoyable afternoon despite not finding Fulvia Checkerspots. Silvery Blues and Olympia Marbles should be out a couple more weeks before they disappear for the year so stay alert to the possibility of seeing them.