Quick! What's orange and black and tan and metallic with sea-blue highlights?
Hey, look for yourself! I'm not making this up. Check out the post pix. See, orange and black and tan and metallic with sea-blue highlights…and no, it's NOT a beetle, but a moth. That's right—moth! Unlike most moths which keep their wings outspread when resting or feeding, this one with the fancy paint job—the Ailanthus Webworm Moth, Atteva aurea—keeps its wings rolled tightly against its body.
The Ailanthus Webworm Moths are part of a family known as "ermine moths," most of which are found in the tropics. Ermine moths build communal web nests for their larvae. Originally native to South and Central America, and possibly south-Florida (various texts disagree on this point), the Ailanthus Webworm Moth was once found only concurrent to the historic habitat range of its larval host plant, Simarouba glauca—commonly known as Paradise Tree. When another, quite similar tree species, Ailanthus altissima, or Tree-of-Heaven was imported as part of the attempt to get a silk industry started in the U.S., the webworm jumped hosts. It is from this newer host plant that the moth received its common name.
Though the American silk-making business fizzled, the Ailanthus tree quickly became popular with gardeners and lanscape nurseries because it was flowering, fast-growing and undemanding, thriving in wastelands and disturbed areas, and amid the exhaust-fumes miasma of a big city. This is the tree famously referred to in the best-selling book by Betty Smith, A Tree Grow in Brooklyn. As Ailanthus trees spread their way across the continent, so did the Ailanthus Webworm Moth.
[As it turned out, Ailanthus trees spread too well, soon becoming invasive in many areas and earning the derisive nicknames, "ghetto palm," and "tree-from-hell." Moreover, it's habit of putting out root suckers broke up foundations, roads, sewer pipes and other underground lines, and sidewalks. Too, much like a walnut, the Ailanthus tree puts out a natural chemical herbicide, ailanthone, that inhibits growth in nearby plants, thus helping the Ailanthus to thrive. Finally, those pretty yellow flowers smelled like male cat urine, prompting the unflattering but honest epithet, "stink tree."]Ailanthus Webworm Moths are ecologically harmless, and actually serve as a beneficial pollinator as they go about visiting and feeding on various plants. Most moths seen in the northern states probably don't manage to overwinter, though a new generation migrates in from the south each summer.
Incidentally, the only reason I know a little bit about these bright-colored creatures, and was able to recognize them when I recently spotted several feeding on a clump of boneset, was that a year or so ago, my friend George, of the splendid Transit Notes, posted a bug photo he'd made which he hoped some reader could help identify. I had no idea, either, but I liked the photo and the crazy-patterned look and gaudy colors, and decided to make it a sort of mini-mission to figure the puzzle out. It took me about an hour and looking at a lot of possibilities—I started out thinking beetle—before I stumbled in the right direction and managed the identity. But once seen, it's not a creature you soon forget.
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