Invader!? A White Moth was Resting in the Arboretum

 

We spotted an all-white moth on the exterior of the Science Building, Mickle Hall, resting on a concrete window ledge near the arboretum shed. It's small, measuring less than an inch in length, and it is mostly inconspicuous against the gray cement.

 

Surprisingly, the proximity of the camera didn't seem to bother the moth―hence it was subjected to some close-up photography. The wings look very soft and legs carry black markings. This delicate creature is very neat! Which species of moth might we be looking at? Consulting our most popular search engine for 'white moth' results in immediate & sheer terror: the white satin moth (Leucoma salicis), an invasive species known for large-scale defoliation.

After extensive combing through online image catalogs, notably the Pacific Northwest Moths hosted by Western Washington University, another possibility arises: it's simply a native nuisance, the fall webworm (Hyphantria cunea). Zooming in on the photo, we see a yellowish color on the front legs, which is a characteristic of our fall webworm. A more thorough examination was not conducted, i.e., the moth would essentially have to be killed and autopsied, so we cannot give a firm identification of this individual. But we must note that fall webworm caterpillars were previously hard at work in the arboretum, feasting on a young sweetgum; you can read that blog post here.

Tree of the Week: Sweetgum (Liquidambar styraciflua)

For the past two weeks, you may have noticed ripe fruits on the ground around our young sweetgum (Liquidambar styraciflua.) Some gum balls can be found still attached to the tree. This tree is approximately 10 years old, and over the past several years we have followed it closely. Its exact age is nevertheless unknown due to its origin as a volunteer. You can read more about this individual here, here, and here. 

 

Sweetgum fruits (or 'gum balls' as they are popularly called) are generally thought of as troublesome and trashy. It's unpleasant, and potentially hazardous for those traveling barefoot, to step on a gum ball―they are large and prickly. Furthermore, on the ground under mature trees, the fruits are numerous.

But gum balls aren't all bad. A local Shreveport resident, Linda, recounts how as a girl of four living in rural Rapides Parish, she and her older sister would use gum balls to make Christmas tree ornaments. The sisters would wrap gum balls in pieces of aluminum foil, pressing it into the prickly fruits, and then hang the shiny orbs from the branches of their Christmas tree. Attaching a small bow made from scrap pieces of ribbon adds a little holiday color.

 

Another Shreveport resident, Sidda Ogea, has also found beauty in the prickly gum balls. Sidda spray painted the fruits gold and incorporated them into a holiday display, or altar, celebrating the Virgin Mary.

 

Working closely with sweetgum fruits will teach you something about the reproductive cycle of this species. Shaking or thumping these fruits releases seeds and other tiny pieces of plant material, some kind of natural packing material.

 

The seeds are the larger pieces. They measure a ¼ of an inch in length. We ought to plant a few seeds in the arboretum to have a replacement for our current specimen.