Two Years Ago Today: Butterflies and Caterpillars

Two years ago today, on our way from here to there or back again, MOH and I hiked our usual central Nevada trail from Highway 50 near Cold Springs to the Cold Springs Pony Express station, high on an alluvial fan on the west side of the Desatoya Mountains. The first hike report, about horned lizards we saw on the trail, is here.

It was spring, and the usually dry creek, which must have at one time provided year-round water to the station, was muddy, though not flowing.
Several Painted Lady butterflies were hanging around in the creek bottom, patiently waiting to have their pictures taken.
The butterflies were eveywhere, and it was hard not to get two or more in the same photo. Here's one that posed for a considerable period of time, opening and closing it's wings so I had time to get the perfect shot.
These butterflies are officially known as Vanessa cardui. They can be found almost everywhere: for example, I've seen them flying by in the middle of the Black Rock Desert.
After observing the butterfly convention and taking several photos of the station itself (not yet posted anywhere), we decided to mosy back to the parking area down near the highway, taking an unmarked route along a dry wash to a nearby side road.
We came to a bush in the dry wash, possibly a Purshia tridentata, that was overgrown with caterpillars.

Caterpillar closeup.

Some bushes, like this one, were covered with Painted Ladies...
...and tents crawling with striped caterpillars.

Although the butterflies and caterpillars were associated closely together in time and space, I was pretty sure that the Painted Lady was not involved in stringing such wild, ever present white tents on so many bushes.
And it's true: the western tent caterpillar, Malacosoma californicum, is unrelated to the often gregarious, usually friendly, and brightly colored Painted Lady. Indeed, the western tent caterpillar gives way, eventually, to a rather plain brown moth and is known primarily for its defoliation of bitterbrush, willows, cottonwoods, mountain mahogany, and other trees and shrubs.