Larose Forest. I photographed this caterpillar in Larose Forest about 6 years ago and was never sure if it was a Harris's or a Baltimore Checkerspot as they look nearly identical. If it had been found on a plant that might have helped as this species only feeds on flat-topped aster. Thanks to Ross Layberry, however, who confirmed that there really is a faint black stripe along the back of the caterpillar, a defining characteristic to separate one species from the other!