Q: Yesterday I noticed the leaves were gone on our Desert Willow. As I got close I saw the same type of worm/caterpillar that were found on tomato plants back in Pennsylvania. There were four or five about five or six-inches long and two smaller ones. What are they? I removed them and have not found any more on any other plants.
A:Β Your insect is the rustic sphinx moth caterpillar. They are common across the U.S. and are not considered to be a pest insect worth managing. They will eat a few leaves but there usually arenβt enough of them to defoliate a tree. Picking them off the plants is often enough and as you saw they are only around for a short time before they crawl off to pupate. They are closely related to the tomato hornworm you remember from back in PA but they are a different species and feed on different plants.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed to
