Agathymus stephensi

California Giant Skipper

This is an agave-feeding skipper that flies ca. September-October in the desert from southern California into Baja California. The type locality of "La Puerta" is clarified by H.A. Freeman as Mason Valley, in San Diego County. Freeman has the following distribution for this skipper: "Western Colorado Desert of Californa; type locality [Mason Valley]; Banner Grade; Sentenac Canyon, 9-10 miles east of Julian; Palms to Pines Highway [i.e. highway 74 out of Palm Desert up to the Santa Rosas such as Cactus Spring Trail]; San Felipe Valley; Vallecitos; near Jacumba. Northern Baja California, Mexico" (Journal of the Lepidopterists' Society, 1969, Supplement 1).

Agathymus stephensi was named (as Megathymus neumoegeni stephensi) by Henry Skinner in the Philadelphia-based journal Entomological News, March, 1912, Vol. 23, No. 3. It was then illustrated - a photograph unfortunately - in Vol. 2, No. 1 (1913) of Contributions to the Naturnal History of the Lepidoptera of North America by William Barnes and J.H. McDonnough. I much prefer the often-beautiful drawings from the older journals. H.A. Freeman revised the genera of the Megathymidae in 1958, introducing the genus Agathymus (The Lepidopterists' News, Vol.12, nos.3-4 (1958)). By then, stephensi was recognized as a species separate from neumoegeni.

Agathymus stephensi - California Giant Skipper
Agathymus stephensi flies in the Colorado Desert in the autumn. Late September along Cactus Spring Trail in Riverside Co. is a good time and place to search for these butterflies. September 28, 2019.
Agathymus stephensi - California Giant Skipper
Another Agathymus stephensi along Cactus Spring Trail about a week later. October 6, 2019.
Agathymus stephensi - California Giant Skipper
Same individual showing the underside. These can be pretty tame and relatively easy to photograph.
Agathymus stephensi - California Giant Skipper
This one was one of a half-dozen stephensi I saw along Cactus Spring Trail in Riverside Co. on September 20-21, 2014.
Agathymus stephensi - California Giant Skipper
California giant skipper from Plum Canyon, Anza-Borrego Desert State Park, on October 3, 2014.
Agathymus stephensi - California Giant Skipper
A collage of Skinner's description of stephensi in 1912 and the first illustration, which was published in 1913.

©Dennis Walker