Small Rivulet Perizoma alchemillata

This delicate moth earned its charming common name—the small rivulet—for its appearance that resembles a tiny stream flowing across the wings. First scientifically described way back in 1758 by the great Carl Linnaeus himself, it's one of the oldest-known moth species in our modern scientific records. Like all geometer moths, the caterpillars move by looping along stems and branches, a behavior that earned the family their other nickname: measuring worms.