The moth is often portrayed as the butterfly’s homely, drably-dressed cousin. In truth, they can be quite colorful in hue and in life history. Moths can spend the winter in any of their four life stages: egg, larva, pupa or adult, depending on the species. Finding cocoons (pupa) this time of year is tricky, because they’re often encased in leaves and smartly camouflaged. I have found a few caterpillars and adults at Mount Pisgah lately, though. 

You might have made the acquaintance of the orange and black woolly bear above. Folk tales say the size of the orange band on this caterpillar foretells the severity of the winter. This theory has been disproven, though, with several studies showing no correlation of weather to color band. However, there may be some sense to the idea that the more orange there is, the milder the past winter was. That’s because the caterpillars are mostly or all black when they emerge, and the orange band gets wider as the temperature warms. So, longer summer = wider band.

Woolly bears are immature Isabella tiger moths. Until recently, I had no idea what the adult looks like, and there are good reasons for that. They live at most a couple of weeks, and they fly mostly at night. I’d love to see one. They’re yellow with a deeper yellow underwing that is orange to pink on females. 

The caterpillar on the arboretum sign is a bagworm, which is a moth in the Psychinae family. This is one weird moth! I’m waiting for confirmation from the incredibly helpful folks at but I’m fairly confident this is Dahlica triquetrella. These moths are only female, they reproduce parthenogenically. They spend the winter as larvae, and to increase stealth, they accumulate debris like lichen, bark, or in this case sand, to make a sort of live-in Snuggie. This one, however, is failing at the camouflage game by posing on a lime green backdrop. The moths pupate in early spring, and females emerge from the bag a couple weeks later. They turn around and lay eggs, without male help, back into the empty bag. The adult moths are wingless, don’t eat, and only live a few days. Wow. 

I’ve seen a few brown and tan adult moths, wings included, on trees this winter. I think all of them have been species of geometer moths. Geometer caterpillars are the ones that have a big gap between the front and back pro-legs, so they measure (meter) the earth (geo) as they inch along. I’m going to guess the one in the photo is a winter moth, because they live as adults into the winter, then lay eggs that emerge as larvae in the spring. 

Female adult winter moths don’t have operative wings. Winter moths came to Oregon from Europe and are visually similar to a native, the Bruce spanworm moth. Remarkably, the two species can interbreed. 

Stay curious!
Karen Richards


Discussion of the woolly bear forecast: Accessed 2/22/21.

Pictures and descriptions of bagworm moths: Accessed 2/22/21.

Tale of winter moths from Alaska: Accessed 2/22/21.