I have Ehrharta growing in my backyard. It is a very common weed. It was brought to the UC Berkeley campus on the shoes of researchers, and has spread everywhere. Including my yard. The Grass Skippers love it. They lay their eggs on the underside of the leaves.
The eggs are white and pretty easy to find. The caterpillars sew themselves into a leafy tube. I think the Ehrharta makes this easy to do because the blades are soft and wide. They are not much fun to raise because the caterpillars are generally hiding. But it is not that hard.
Grass skippers are kind of brownish/orangeish butterflies. People ask me, "Are those butterflies?" Maybe because they are not showy. Yes, they are butterflies. Most day-flying lepidoptera are butterflies. They also ask, "What are those butterflies with four wings?" This really confused me at first. All butterflies have four wings, but given the way they hold them, I guess people think they have two. When skippers land, they look different. They often hold their wings in four separate planes so that you can see them clearly. So, the butterflies "with four wings" are skippers.
Ehrharta
There are other skippers, like the common checkered skipper. It is gray and white. It doesn't hold its wings in four separate planes. And it lays its eggs on mallows. Completely different from grass skippers.
Umber Skipper
And there are several different grass skippers in this area. Fiery and Umber are the most common. And they are difficult to tell apart, so I don't even try. I don't understand why the spellings are
F-I-R-E and F-I-E-R-Y. They are both all about fire. Weird!
Ehrharta
And I don't understand the spelling of Ehrharta either. It sounds more like "air harta." Must not be derived from English.
Grass Skippers do use other grasses, like Bermuda Grass and St Augustine Grass. And they must use some kind of natives. But I unusually see them on flowers or Erharta. They love Ehrharta! It is a great host plant. If you are planting a butterfly garden, leave some grasses at the edge of a lawn to grow tall and go to seed. This creates habitat for the skippers, and lets them complete their lifecycle on the hostplant.