Urban Wilds Vol. 5 – Luna Moths

Photo by ggallice via wikipedia

Urban Wilds is written by Lela S. Lela lives in Petworth. You can read Lela’s previous post on raccoons here.

Insects are as close as we get to alien life on Earth – skeptics, just google “macro photo insect.” Their lives run on cycles and timing that can seem cruel or bizarre from a mammalian standpoint. We’re about to witness a big upswing in the insect interest factor when Brood II of the periodical cicadas hatches out after spending 17 years underground. Luna moths, among the most beautiful of insects, have a less dramatic but equally exotic life marked by a complex, colorful development and an early death.

The color of pistachio ice cream, with feathery antennae and long ‘tails’ at the bottom of each wing, Lunas are among our larger moths, with wingspans up to five inches. (You may recognize them from a pharmaceutical ad that aired a few years back.) These gorgeous animals, widespread in eastern North America, are hatching now in our area. Luna moths are similar to cicadas in that their adult phase is poignantly short. After hatching, a Luna caterpillar will go through five stages, or instars, as an increasingly large bright green caterpillar. Pupation takes about two weeks. After emerging from their cocoons, the insects immediately begin to breed. A female Luna sends out pheromones that males of the species can pick up, using their antennae, from several miles away, and glues her 200 or so eggs to host tree leaves. They have to move quickly, because Luna moths pupate with a cruelly efficient structure: they don’t have mouths. Once hatched from their cocoon, they only live long enough to breed and lay eggs, and die within a week.

Continues after the jump.

Moths sport some of the most wonderfully odd or mystical names out there. In the DC area alone, we have species like the Mournful Thyris, Grapeleaf Skeletonizer, Unsated Sallow, Shy Cosmet, and Green Marvel. The Lunas, rather bland sounding in comparison, are named for the moonlike eye spots on their wings, but it can’t hurt the comparison that they’re nocturnal, and use the moon to navigate, like most moths.

Luna moths are becoming increasingly threatened by habitat loss, pesticide use, and the proliferation of bright (moon-like) lights, which disorient them. They’re still considered common, but because the butterfly stage is so short, are hard to run across. You may spot them out in the woods, or clinging to a screen door or window at night.

11 Comment

  • Great post! I’m going to keep an eye out for these guys; they are beautiful!

  • You picked my very favorite bug, and a great photo of her. (I think that one is a her… narrower antennae.)

    My dad is a moth hobbyist. He raises the giant saturniids inside zippered mesh branch covers, to protect them from birds. He moves them gently to a new branch when they’ve eaten everyone on the old one. And when they spin their cocoons, he puts ’em in a cage to hatch, mate, and lay eggs. Then he plants the eggs on appropriate host trees all over his region, to increase the wild population (keeping a small fraction of the brood for his next generation, of course). In the 10 years he’s lived in his current house, we’ve gone from never seeing a giant silkworm moth to seeing them routinely, all over the county. Being big and colorful and slow, with no natural defenses, they’re heavily preyed-upon by birds. But enough seem to make it.

    Here, check out my favorite caterpillar, a 5th (final) instar cecropia: http://lifecycle.onenessbecomesus.com/cecropia%2072409%20032crop.jpg. If they get their favorite food (mulberry or cherry tree leaves) they can get to be the size of a small hotdog!

    • Working as a tree pruner in a huge commercial nursery we encountered dozens of cecropia caterpillars about to pupate. We were told to kill them since they were destructive to the young trees. I collected them and once in captivity they spun their cocoons. The next spring within a period of two days I had 20 of them slowly flapping in my house. I turned them loose and some mated while in my yard.

      • You, sir or madam, are gold. Did you take pictures of your cecropia-fest? I guess I can see the point of view of the nursery owners– the caterpillars DO eat leaves– but the very idea of killing a giant silkworm is so abhorrent…

  • There’s something magical/heavenly about these creatures. Seeing one it like running into a friendly ghost.

  • Anyone know where I can find some death’s head moth larvae?

    • In a tomato patch…?

      The tomato hornworm (green body, red hook on the tail) produces the death’s head sphinx. Not sure why you’d want to cultivate a pest for a relatively meh-looking moth.

      Anyway, Bill Oehlke is the man to see. If it’s a saturniid for sale, he’s selling it. Google him. He’s a god to my people.

  • It rubs the lotion on the skin or it gets the hose.

  • This is a fascinating and beautifully written post. Reading this has made my day.

    Thanks, Lela! 🙂

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