Steelman: Caterpillars on the move

Caterpillars of all sorts seem to be plentiful right now. Some become beautiful butterflies and moths (order: Lepidoptera), while others become nondescript moths. Monarch, black swallowtail and pipevine swallowtail caterpillars tend to be abundant at the UT Gardens. "We intentionally grow plants that attract these spectacular caterpillars and butterflies to the gardens," said Jason Reeses, with the UT Gardens in Jackson. The horticulturist recommends interested gardeners and butterfly enthusiasts check out this website to help identify specimens: http://www.butterfliesandmoths.org/.

Reeves says some of the specimens are really unique. "Last week, I found the amazing, wavy-lined emerald moth (Synchlora aerate) caterpillars on my zinnias and marigolds at home. This caterpillar attaches flower petals to its body to act as camouflage.

"Recently, I found the Paw Paw Sphinx moth caterpillar (Dolba hyloeus) feeding on my winterberry hollies. Its appearance is similar to the tomato hornworm, which can be seen at http://www.silkmoths.bizland.com/dhyloeus.htm."

Reeves also commented that white wooly worms, or wooly bears, have been eating away at the zinnias at the UT Gardens in Jackson. He says because they are so large and easy to see, that he justs pick them off the plants. "You can see one at http://www.eons.com/groups/topic/1085975-A-very-white-woolly-bear-worm," he said.

This time of year Reeves says dogwood sawfly can be a problem on red twig and yellow twig dogwoods. For more on dogwood sawflies, visit http://woodypests.cas.psu.edu/factsheets/InsectFactSheets/html/DogwoodSawfly.html.

"Also, watch for Redbud Leaffolder (Fascista cercerisella) on your redbuds. This caterpillar folds the leaf over itself and holds the leaf together with silk while skeletonizing the leaf as it feeds. They are considered to be damaging only on young trees that don't have a lot of foliage," Reeves said. He recommends http://entnemdept.ufl.edu/fasulo/woodypest/401.htm for more information.

Caterpillars are some of the easiest insects to control. An organic insecticide containing Bt (Bacillus theringiensis) is the safest way to control them. Bt primarily targets caterpillars and mosquito larvae but will not work on the dogwood sawfly larvae. Chemicals with the active ingredient Spinosad will work on all caterpillars with minimal impact on beneficial insects. Reeves said Sevin dust or liquid works as well but is less selective in that it will kill many insects, including honeybees. He recommends always following label instructions and precautions when applying any insecticide.

"Just remember, not all caterpillars are bad," said Reeves. "Be sure to identify the caterpillar you have before treating with insecticides. The monarchs, swallowtails and other beautiful winged Lepidoptera will appreciate it! You will too when you see them flying about your garden."

Bruce Steelman

614 Lehman Street

Phone: 615-563-2554

E:mail- tsteelm2@utk.edu