Wavy-lined

October 14, 20254

Melissa tends to keep the back door to the porch open to help provide a breeze and keep down the humidity for the succulents.  If the air conditioner is not running, she will often keep the house door open as well.  This provides a breeze for us and allows the kids to roam freely in and out of the house without having to get up every time they hear a noise or want to go outside.  While this is convenient, it allows house flies (Musca domestica), moths (order, Lepidoptera), and other flying insects (and occasional birds) to fly enter both the porch and the main house.  I have tried to combat this by placing a bug-zapper next to the doorway.  The blue light is not visible during the day but does attract moths at night.  When it is time for a final constitutional, Loki will wait at the door for Melissa or I to go first to “protect” him from the sounds of the moths hitting the zapper.  When I got up yesterday, I noticed one of the moths had avoided the zapper and was attached to the wall above the kitchen sink.  When I looked closer the moth’s coloration was “wavy-lined”.

When I went online, I found the wavy-lined emerald moth (Synchlora aerate), or camouflaged looper, is a species of moth of the family Geometridae.  The species is found in the US and Canada and was described by Johan Christian Fabricius in 1798.  There are dozens of species in the subfamily of emeralds in North America.  Most look incredibly similar, being green (sometimes tan) and typically resting with their wide wings spread out to the sides.  The key identifying features for the species are the mildly wavy white lines that run across the wings, a pale green fringe on the wings, and a long, thin white stripe running the whole length of the abdomen.  The adult wingspan is about 0.67 inches (17 mm).  The caterpillar of this species is an inchworm (looper) that camouflages itself from predators with small clippings from flower petals they are feeding on.  The wavy-lined is a common moth that has two or three broods a year and overwinters as a partially grown larva. 

The wavy-lined emerald moth is an important food for birds and other predators.  While some insects use camouflage or mimicry to outwit predators, the wavy-lined caterpillar blends these two defenses.  Insect camouflage often refers to creatures like stick bugs (order, Phasmatodea) that have evolved to look like their surroundings.  Mimicry means looking like a completely different creature, like the less toxic Viceroy Butterfly (Limenitis archippus) which looks like the toxic Monarch (Danaus plexippus).  The wavy-lined larva will attach bits of the plant material on which it is feeding to its back with bits of silk to blend into its host plant and avoid detection.  When it feeds on a different plant it will “wear” the appropriate foliage.  These fragments start off colorful (to blend in with the flower) and then dry out to look like a chunk of debris.  It also seems to detach and replace the parts as they wilt, keeping the larvae covered in fresh adornments that match its meal.  While it is essentially using camouflage, the insect is an active participant in the process, mimicking whatever flower it feeds on. 

THOUGHTS: While I have no problem swatting the flies and mosquitoes (family, Culicidae) that invade my house, I did not feel threatened or bothered by the wavy-lined emerald moth.  It spent the entire day resting on the wall as Melissa and I came and went around the sink, allowing me to admire its delicate lines many times.  When I got up this morning the moth was gone.  Hopefully it made it past the bug zapper on its way outside.  Most insects tend to go about their business and do not seek out humans.  Flies and mosquitoes are an exception and use humans as a source of food (dead skin, blood), water (sweat), and salt.  The fact that the moths are aesthetically pleasing is another plus.  Sometimes I need to remind myself that every creature has a role to play in the larger biome.  Act for all.  Change is coming and it starts with you.