Tunnell Vision - April 2022

On March 2nd of this year, the Entomological Society of America renamed the gypsy moth to the spongy moth. For me, not realizing that this name was offensive, it was kind of like finding out that Pluto isn’t a planet anymore. The solar system as it was, was drilled into our heads in elementary school, now it’s changed based on science. Much like the numerous scientific plant names that have changed since I’ve been in the industry, I learned them as one name and now they’re another. For me, with plant names, I usually stick with what I learned originally, just like Pluto is the ninth planet. How long or how many generations will it take to consistently refer to something by its new name? Now that names are changing because they are offensive, maybe it will happen sooner than later. 

The spongy moth now refers to this insect’s egg casing rather than the migratory behavior of the older adult caterpillars. The caterpillars will march from the leaves, down the branches and trunk and rest in shady spots each day. The spongy moth is an invasive pest that migrated from Europe in the 1800’s. They look much like our native eastern tent caterpillar, both are about the same size, hairy, and have bands of black and brown colors with narrow yellow stripes, and blue spots. But the spongy moth also has red spots, the distinctive difference between the two. They are very harmful to deciduous hardwood trees, especially oak. The damage can range from light to near full defoliation. Most trees will survive a single infestation, but continual damage can severely stress a tree to the point where it can become susceptible to drought, cold, disease and other insects. 

The other major difference is their eating habits. Eastern tent caterpillars prefer to feed safely in their tent. Spongy moths do not make webbing and eat out in the open. After eating, they like to hide or find a nice shady spot, even on the ground or an object close by. Finally, we see the damage from our native tent caterpillars earlier than the spongy moth, which usually gives trees a chance to grow out of the damage. Tent caterpillars can become active in March compared to the April/May time of the spongy moth. 

Our state has done an excellent job on monitoring and controlling the spongy moth population. As a matter of fact, we have participated in some of these monitoring programs in the past. As mentioned, both pests can be destructive, but there are many options for control if one or both insects decide to visit your landscape.