Apodemia mormo "cythera"

Mormon Metalmark

True cythera has a type locality west of Lone Pine, in Inyo County. The range of this taxon is not yet known, but preliminary genomic work suggests it gets at least to the Greenhorn Mountains. In much of the current literature, populations on the northern edge of the transverse range and into the Mt. Piños area are considered cythera. That is almost certainly wrong, but until we have a better grasp of the situation, this name will have to do.

There is a remarkable population of "mormon metalmarks" that fly in a single brood ca. late July into September on the northern side of the San Gabriels and east to around Coxey Meadow in the San Bernardinos. My favorite place to see them is up Big Rock Creek Road, where they take nectar at the many yellow scale broom flowers along the road. This golden-orange butterfly is starkly different - visually - from nominate mormo, which is very dark. In this particular creek area, there is plenty of late summer blooming Eriogonum heermannii, the larval food plant of this population. I soon found this butterfly up at Mt Islip to the south around fasciculatum, and at Grizzly Flat as well, all in the same general part of the San Gabriels. Some thirty air miles east at Mojave River Forks, a similarly orange late summer/fall-flying mormo may be found on Eriogonum fasciculatum and E. wrightii. These populations along the desert edge foothills of the San Gabriels and western San Bernardinos are well to the south of true cythera. According to the Pratt and Emmel article from 2011 in American Butterflies, our desert-edge populations have a narrow blend zone around Gold Mountain, northeast of Big Bear Lake, with the nearly black fall flyer we've been calling "near mormo" that uses wrightii around Wildhorse Meadow and vicinity. Stay tuned.

Apodemia mormo cythera from Big Rock Creek, on the northern side of the San Gabriels. Note the extensive yellow on the hind wing. July 29, 2009.
Apodemia mormo cythera - Cythera Mormon Metalmark
A ventral of Apodemia mormo cythera from Big Rock Creek. July 29, 2009.
I revisited Big Rock Creek on August 17, 2010 and again found Apodemia mormo cythera in good numbers on the rabbitbrush. For those used to seeing the very common, widespread virgulti or the dark varieties of mormo, seeing these much more golden yellow cythera from this location should be a treat. When fresh, they really are striking.
Apodemia mormo cythera - Cythera Mormon Metalmark
Another ventral, same day as above. These single-brooded butterflies are easily found in late summer and/or early fall up Big Rock Creek Road where rabbitbrush is blooming. The caterpillars will do some of their feeding next year in the early summer when the buckwheat flowers are in bloom.
Apodemia mormo cythera from Mojave River Forks
Apodemia mormo cythera from Mojave River Forks, about 30 miles east of the above population. These have an interesting phenotype, with small white macules and extensive dark orange coloration. Sept. 6, 2007. They fly only in the late summer/early fall, and the buckwheat hosts are E. fasciculatum.
Apodemia mormo cythera - Cythera Mormon Metalmark
Apodemia mormo cythera from below Mt. Islip in a patch of E. fasciculatum at approx 6790' elevation. The phenotype is close to what one sees a few miles downhill to the north in Big Rock Creek (4-5000' elev.), where the mormo cythera are almost yellow.

©Dennis Walker