Crawlies with Cri: by Christy Solo

(Photo by Christy Solo, Illinois Valley News)

If you’ve seen this week’s adorable mini-Muppet of a crawly in real life, you are one lucky Oregonian.
Meet the warm-chevroned moth (Tortricidia Testacea), also known as the early button slug moth.
That second name may sound weird, but their teeny, tiny ‘pillars really look like “What if a slug were a button?”
For simplicity’s sake we’ll call them “buttons” for the duration of this article (because that’s cute and takes less time to type than either of their full common names).
Why would you be lucky to see one in Oregon? It’s not just because of their tiny size – adult buttons are just under one-half inch – but also their rarity.
To date there are just 17 recorded sightings of buttons in Oregon: 16 adults and one impossibly small caterpillar.
Buttons are somewhat common east of the Mississippi, but in the West they seem to be making a home in Washington, Oregon and California. The earliest Oregon sighting was back in 2011 so they seem to be new to the West Coast.
Buttons are in the Family Limacodidae – slug caterpillar moths along with 49 other species. Not one of those other 49 species can be found in Oregon.
In fact, only one other slug caterpillar moth species, Monoleuca occidentalis, lives on the West Coast and they only live in California and nowhere else in the United States.
The other 48 species of slug moth all live east of the Mississippi.
Slug caterpillar moths in general are pretty darn cool. It’s worth doing an internet search when you’re done reading about buttons.
Their sluggish name isn’t exactly spot on. Most of the ‘pillars look more like sea slugs than land slugs. Some are quite fancy. The adult moths tend to be chunky and cute. A winner of a moth family all around.
Except – most of the 49 other slug caterpillar ‘pillars are very much “look but don’t touch” critters because they are covered in small hairs that pack a sting.
Button moth ‘pillars lack that defense. Instead they went in for being very small and looking like “just an odd bit of stem or leaf” or even a leaf bud.
An adult button’s best defense is that “I’m bigger than I look!” stance, with the end of their abdomen curled up over their head. Still, it’s hard to take an adorable blue-eyed Muppety moth seriously.
Button ‘pillars eat the leaves of a variety of hardwood trees, including beech, birch, black cherry, chestnut, oak and witch-hazel. The pictured button was perched a few feet from a cherry tree in my yard.
Don’t panic about a sudden plague of buttons defoliating your trees. First, there are so few of them they’re inconsequential. Even if we had large numbers of buttons, they’re so small just a few leaves would be enough for the very slow-moving pillars to grow to their final instar.
Moreover, female buttons are savvy and lay their eggs singly on the underside of the leaves of the food-plant, so the ‘pillars will be spread out making any damage even less noticeable than if 20 of them went to town on one branch of leaves.
Bitty buttons overwinter in cocoons that are sturdy and brown. They resemble cardboard and have a cap on one end from which the adults eclose from June – August. They are attracted to light, so if you don’t spot one on a hardwood tree, you may see one around a porch light. Good luck!
Photo link: https://www.inaturalist.org/observations/181342332