Measuring the earth, one millimetre at a time

Here's another of my midnight visitors. I've never seen an inchworm this tiny before. It was hurrying across my nightstand, a mere thread stretching out, then folding itself in half. I moved a box aside, and it leapt onto my finger.

As thin as a sewing thread.

Racing across my palm.

It's about 4 mm. long.

And here it is, folded.

The inchworms are the larvae of the Geometrid moths; they get their names, both common and scientific, from their walk; it looks as if they're measuring as they go.

Other caterpillars have 5 pairs of rear legs, called prolegs; the Geometrids have 2 or 3. They grab the substrate with their front legs, then bring forward and attach the rear legs. Then they stretch out their front end again, grab and repeat.

This little guy will grow; the moth larvae go through 5 instar stages (growth between molts) and may measure 10 times his present length by the time he's ready to pupate.

I think it may be the Pale Beauty moth, Campaea perlata, common in this area, going by the stripy body pattern. I've loaded it to iNaturalist; someone there will know.

They eat plants, not found in my bedroom. I would have taken him outside, but while I checked the photo on my camera, he found a place to hide. Sorry, little guy!

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Aquí tenemos otro de mis visitantes nocturnos. Nunca antes he visto una de estas orugas geomensoras tan pequeña. Esta se apuraba cruzando mi mesita de noche; se parecía a un hilo de coser que se extendía, luego se doblaba, volviéndose a extender inmediatamente. Arrimé una cajita, y la oruga saltó hacia mi dedo.

    1. Del grosor de un hilo.

    2. Aquí está en la palma de mi mano.

    3. Mide unos 4 mm. de largo.

    4. Aquí se ve como se dobla.

Estas origas medidoras son las larvas de las polillas Geomensoras; se llaman así por su manera de proceder; parece que van midiendo el camino.

Otras orugas tienen 5 parejas de patas traseras, pero las geomensoras tienen solamente 2 o 3. Para caminar, fijan las patas anteriores en el sustrato, luego se doblan, trayendo las patas traseras hasta casi tocar las anteriores. Luego se estiran, avanzando las patas anteriores a la máxima distancia posible, fijándolas de nuevo, para repetir el movimiento.

Esta larva va a crecer; pasan por 5 mudas, al desechar la piel que ya les queda apretada. Al llegar a la hora de formar una pupa, medirá tal vez 10 veces su tamaño actual.

Creo que puede ser la polilla "Bella Pálida",  Campaea perlata, que se encuentra comunmente por aquí; el diseño de su cuerpo se parece a la de esta polilla. Subí las fotos a iNaturalist; alguien allí me podrá informar mejor.

Las larvas comen plantas, y no las iba a encontrar en mi cuarto; la hubiera llevado afuera, pero mientras miraba la foto en la cámara, se fue a esconder. Lo siento, bichito.

Green-feathered visitor

This little moth turned up on the shade of my bedside light the other night.

Pasiphila rectangulata, against the light. About 3 cm, wingtip to wingtip.

One of the amazing people at BugGuide identified it as a Green Pug moth, one of the inchworm family.

Against the wall, the green feathers show up.

I'm keeping a camera on my bedside table, these warm days. No telling who'll come to visit!

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Esta palomita se detuvo en la pantalla de mi lámpara de noche. Uno de los asombrosos expertos de BugGuide, la identificó como Pasiphila rectangulata, de la familia de los geométridos, los gusanos medidores. En inglés, su nombre común, Green Pug, trae a la mente los perros pug, pero verdes.

1. En la pantalla, contra la luz. Mide de 2 a 3 cm, desde la punta de una ala hasta la punta de la otra.
2. Contra la pared, con la luz de este lado ahora, se le ven las plumas verdes.

En estos dias, cuando ya no hace frio, tengo una cámara siempre en mi mesa de noche, en espera de visitas.

Ghost in the rain

How, when everything around him is dripping wet, does he manage to keep those wings so dry?

Phantom hemlock looper moth, Nepytia phantasmaria, ♂. A geometrid.

The last time I saw these, in September of 2019, they were everywhere. I found this one in the woods behind the museum, and then wandered all the trails looking for more. I only saw this one. They don't like bright light; they're night flyers, but in the daytime they can be found in shady spots. It may be that they hide from rain, too.

This is a male; if you look in front of the right side of his face, you can see the edge of his feathered antenna.

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¿Cómo es que, cuando todo el bosque está escurriendo agua, y constantemente caen gotas desde las hojas allá arriba, esta palomita mantiene las alas tan secas?

Es una paloma o mariposa nocturna de la familia de los geométridos; o sea que sus orugas son geomensoras. Una paloma fantasma Nepytia phantasmaria, que pone sus huevos en las aguja de los árboles abeto canadiense.

La última vez que vi estas, en septiembre de 2019, las había por todas partes. Esta la encontré en el bosquecito atrás del museo, y luego di vuelta por todos los senderitos buscando más. Solamente hallé esta. Vuelan de noche, pero de dia se pueden encontrar en sitios sombreados. No les gusta la luz fuerte. Pero tal vez se esconden de la lluvia también.

Esta es un macho; si se ve muy de cerca, se puede ver un poco de la antena emplumada que llevan los machos.

Spring fever in November

The temperature is hovering around freezing; frost on the grass only thaws in direct sunlight. Spiders and beetles have gone into hiding. There are no flies to eat, anyhow.

And now, a tribe of tiny, fragile moths have come out to play in the cold. I found four on one window yesterday, not sleeping; when I touched them, they flew away.

A few days ago, I caught a slower-moving one.

Bruce spanworm moth, Operophtera bruceata. ID'd by the line of single dots at the edge of the wing.

There are several species of similar winter-flying moths around here. They all have one thing in common; if they're flying, they're males, out looking for a mate.

The females don't look (to us) like moths at all: they have just a hint of undeveloped wing stubs. (See this photo in BugGuide.) When they emerge from their pupae, in October or November, they crawl up tree trunks, emitting pheromones, and wait for the males to find them.

Then they lay their eggs one at a time in cracks of the bark. In frozen cracks of the frozen bark. And the tiny eggs develop over the winter, changing colour from green to orange before they hatch in early spring.

I don't think I've ever seen a female, but where the males congregate, they're somewhere near.  I've always found the males on walls or windows; maybe I should be looking on nearby trees for their mates.

(Unfortunately for this guy, my spider had just laid eggs and was hungry, so he went into her box and became a spanworm wrap.)

Crazy mixed-up moth

These warm days, the coffee shop where we refuel after walking on the beach keeps all its doors wide open, to catch the breeze. Last Sunday, this moth flew in and settled on the floor near our table.

I think it's a geometrid, a measuring worm moth.

It's a pretty moth, hardly tattered at all yet; a youngster. And do you see what's odd about it? I was so concentrated on getting it all in focus that I didn't even notice until Laurie pointed it out at home.

The wings on the left side are mostly brown, with black designs. On the right, they're mostly grey, with brown accents. And if you look at the thorax, it's also split down the middle. Here, the right is mostly grey, and the left is brown.

Thorax, collar, and upper wing.

I thought it was an effect of the light, but in all my photos, from whatever angle, it's the same. And the lighting was uniform; the shadow falls evenly underneath the moth. Wonky genes?

I've sent it in to BugGuide for an ID.
UPDATE: Triphosa haesitata, a Tissue moth (one of the Geometrids). BugGuide is wonderful!