I love the phrase by Duke Elsner of Michigan State University Extension. In his post, he called the Sphinx Moth Caterpillars “the big cats of the vineyard.” How true it is!
A member of the Hornworm group, one of these was found on my grapevines in September by a visiting MG Trainee. The caterpillar comes in green, orange, pink and cinnamon-to-dark brown. The one found on my grapevines was cinnamon-to-dark brown. The photo at top right shows this coloration and was taken by Maryann Frazier at Penn State Entomology Extension.
The Pandora Sphinx larvae is one of about a dozen hornworms known to feed on grapevines and related vitaceae in the eastern U.S. The adult moth is active only at night and, at times, may be found feeding on nectar from deep-throated flowers. They can hover like Hummingbirds and are attracted to bright lights. On occasion, they can be found resting near flowering plants in the morning hours.
Depending on location, their population will vary year-to-year, and, if the host plant is a small vine (such as one newly planted), one “cat” can defoliate the plant, reducing growth and killing the plant. Fortunately, like the Tomato/Tobacco Hornworm, they are heavily parasitized by predatory flies and wasps. They are not considered a pest except, possibly, in the case of new plantings, therefore, it is recommended that gardeners monitor new plantings of host vines.
Photo References: Pandora Sphinx Moth Caterpillar, Maryann Frazier, Penn State Entomology; http://ento.psu.edu/extension/insect-image-gallery/all-images/pandora-s-sphinx-moth-caterpillar.jpg/image_view_fullscreen. Pandora Sphinx Moth, Will Cook 2007, Montgomery County, VA, 07/13/2007; http://bugguide.net/node/view/270661. Pandora Sphinx Moth Pupa, Janice Stiefel, Sheboygan County, WI, 2007; http://bugguide.net/node/view/149248. Map; http://mothphotographersgroup.msstate.edu/large_map.php?hodges=7859.
Research References / Resources: “Hornworm caterpillars: The big cats of the vineyard,” by Duke Elsner, Michigan State University Extension; http://msue.anr.msu.edu/news/hornworm_caterpillars_the_big_cats_of_the_vineyard. Bugguide; http://bugguide.net/node/view/3937?printable=1. Caterpillars of Eastern North America by David L. Wagner, 2005.
Author: Jim Revell, Bedford Extension Master Gardener
Printable article: Nov2016 Pandora Sphinx
CLICK HERE to read more of Jim’s articles on our “Jim’s Bugs” page. Get to know your insect neighbors! As always, feel free to contact your local Extension Master Gardeners with questions or concerns you may have about insects in your area.