Perhaps it was searching for a thistle.
The Mylitta Crescent butterfly (Physiodes mylitta) did not find the thistle—at least in our bee garden.
What it did find were the leaves of a tower of jewels (Echium wildpretii) where it sunned itself before fluttering off to parts unknown.
This butterfly breeds on thistles, says noted butterfly expert Art Shapiro, professor of evolution and ecology at the University of California, Davis. He monitors the populations of Central California butterflies on his website.
"With the naturalization of weedy European species of Cirsium, Carduus and Silybum, it (the Mylitta Crescent) is now found in all kinds of disturbed (including urban) habitats," he says on this website.
Perhaps the next time we see the invasive bull thistle, Cirsium vulgare, growing in a field or alongside a road, it will be occupied by not only a spotted cucumber beetle (a pest) but a Mylitta Crescent.
Author - Communications specialist