Nessus Sphinx

In the interests of habitat improvement, I really ought to remove every trace of a long-ago Eurasian immigrant known to gardeners everywhere as Dame's Rocket. Hesperis matrionalis, a member of the Mustard family, was brought to North America in the 17th century by colonial horticulturists, but the plant promptly escaped and became quite comfortable in the wild... too comfortable, it turns out. Considered an invasive species in Connecticut, I nevertheless allow it to persist because a. it looks and smells wonderful, and b. it is a butterfly, moth, and bee magnet. The swallowtails, tiger and spicebush alike, and various bumblebees, love the four-petaled flowers, but my prime reason for letting H. matrionalis stick around is that the flowers are beloved by an early-flying hummingbird moth called the Nessus Sphinx. Every late May when the Dame's Rocket reigns supreme, I started combing the blossoms for these marvelous twin-ringed moths and voicing nervousness about their non-appearances. This year, I needn't have worried. Looks like I'll be keeping the Dame's Rocket around for another year.