Cindy Burkhardt had been watching a sphinx moth caterpillar in her garden for several days, but then it disappeared. Soon thereafter, she saw another trundling across a dirt road on Rabbit Mountain.

Q: We’ve had this guy around for the last few days. What is he? A luna moth perhaps? What should we look for in coming days? A: It’s a hornworm, Manduca rustica (aka rustic sphinx moth), to be precise ...