An inchworm in a striking yellow and black jacket is devouring a favorite Florida shrub this summer, but horticulturists say it’s not the only insect making the most of the wet weather.
Prolific plant growth from record May rains and consistent showers means more tender new stalks for bugs to munch on, said Deborah Levulis, a University of Florida environmental horticulturist in Palm Beach County.
Levulis said the variegated pink, white and green leaves of the snowbush are especially attractive to spanworms, and can be most noticeable because the shrubs are often used as a natural barrier for yards.
“They are just one of these plants that make a striking statement in the landscape and if you are using it as a screen and it starts to get decimated by chewing insects, than you lose that look,” Levulis said. “We’ve had a lot of humidity and a lot of rain, so everything has put in an extra dose of growth and is extra lush.”
After a spanworm eats its fill, it buries itself in the ground and emerges in about seven days as the white-tipped black moth. The moths, which span a little more than an inch, have an orange thorax and white tips on their black wings.
They are daytime moths.
“There are moth issues right now, there are butterfly issues and they are all just taking advantage of this excessive growth,” Levulis said. “It’s beautiful to see all the butterflies, but you don’t want to see all your plants decimated.”
Another critter, which isn’t eating plants but may be even more intrusive, is the yellow-banded millipede.
The millipede feeds on decomposing landscape debris, mulch and thatch, but can end up in homes where they typically dry up in the air conditioning.
More plant growth means more landscape debris, which means more millipedes.
“We don’t recommend you vacuum them because the odor can get circulated and really stink,” said Bill Schall, a Palm Beach County extension agent with University of Florida’s Institute of Food and Agricultural Sciences, or IFAS, in a 2017 interview. “If you sweep them into a dust pan, or just pick them up, that is better.”
Levulis said the millipedes are beneficial because they break down debris to create topsoil.
“It’s all related to the weather and how much extra growth we’ve had,” Levulis said about a buggy invasion.
While snowbushes can usually withstand a single assault of inchworms, many attacks in a row may weaken the plant and it will “eventually bite the dust on you.”
To combat the moth, people can wipe the salmon pink eggs from leaves, prune branch tips with many caterpillars on them, and spray small caterpillars with an insecticidal soap.
“Most people can’t take a blemish on the fruit at Publix, so they definitely don’t want a leafless shrub in their yard,” Levulis said.