Silvery Checkerspot on Ageratum

There are quite a number of these relatively small silvery checkerspot butterflies in the garden at the moment. Not as many as the hordes of swallowtails, but still - quite a lot of them. And there is also a lot of ageratum blooming. Which, it turns out, is basically an invasive weed in these parts. I got it from my mother, and it certainly does spread itself (self seed) wildly around the vegetable garden - but it hasn't really escaped into the rest of the property, so it doesn't seem so bad. There are a lot worse invasives out there...