July 4th, 2008
precious metals
One evening last week, just before sunset, I spotted a bead of molten gold on a morning glory leaf in the garden. Closer inspection revealed a mating pair of Golden Tortoise Beetles (Charidotella sexpunctata bicolor). For once, I didn’t have a camera in hand — I was taking vegetable scraps out to the compost heap — so I returned to the house to get one. By the time I returned, the beetles didn’t seem quite so golden. I wondered how that could be. Had I just imagined them to be pure gold and not tinged with red and with a pair of black dots on the elytra (wing covers)?
I checked Stephen Marshall’s Insects: Their Natural History and Diversity to confirm the ID of these beetles and discovered this comment:
The Golden Tortoise Beetle (Charidotella sexpunctata bicolor, often called Metriona bicolor, 5-6mm) changes color from gold to red when excited. Larvae with their protective fecal parasols, are common on Morning Glory (Ipomoea violacea) and related plants. Pinned specimens of these beautiful beetles undergo a one-way transformation from gemlike specimens to drab pinned beetles as they dry out in insect collections.
Interesting and beautiful, no?!
Tags: Golden Tortoise Beetle, Charidotella sexpunctata bicolor
July 4th, 2008 at 8:17 am
Oh my, that’s really beautiful. There was a moment last spring, with the white-margined beetle, when I thought I had a tortoise beetle, but it was not to be. Quite a coup!
They’re certainly magnificent enough even if they lost that golden color you saw.
Also, it’s no surprise at all why they’re named so, is it?
July 4th, 2008 at 9:12 am
What a stunning gem of a beetle. Those colors are beautiful, and how incredibly cool that they can change to flaming gold in the heat of the moment. What evolutionary and artful excellence!
July 4th, 2008 at 11:12 am
these are splendid! Did you return after leaving them some privacy to find them back to their normal colours?
July 4th, 2008 at 2:40 pm
Wow–fascinating.
Like little mood rings? (but probably not heat sensitive)
July 4th, 2008 at 9:20 pm
Tortoise beetles always remind me of my friend John from Colorado. John is a big chrysomelid beetle expert, and has taught me many. many things about beetle identification. Those are great photos. I’ll be seeing a whole bunch of tortoise beetle species in 3 weeks when I’m down in southeast Arizona. I’ll try to get some pictures.
July 5th, 2008 at 8:32 am
I thought that “when excited” citation would be the explanation!
July 5th, 2008 at 11:10 am
Wayne - Yes, aren’t they really quite something? Although very small, they were shining so brightly that they caught my eye from several feet away!
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robin - I love the transformational aspect too. How neat!
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Ruhh - Unfortunately, they had moved off by the time I returned, so I didn’t get to see if they returned to their former gold coloration.
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Nina - Yes, just like tiny mood rings. (-:
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Doug - I didn’t know there were a lot of tortoise beetles in Arizona. I’ll definitely have to be on the look-out for them next time I’m there.
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pablo - The “excited” citation is interesting. Why red? Red for Warning?
July 8th, 2008 at 7:56 am
Bev, it’s the typical tortoise beetle drill down there. You look on morning glories. I typically see the beetles in Madera Canyon and Patagonia. I’m sure they’re lots of other places, too.
July 12th, 2008 at 6:31 pm
Bev - your photos are really super. Always something exciting to see! The beetles are just magnificent and your shots really capture the color!
July 16th, 2008 at 2:13 pm
Wow! They look like little jewels, don’t they? I really enjoy your blog, by the way. I’ve been really stressed out lately and for some reason your photos and observations really calm me down :)
July 19th, 2008 at 5:13 pm
Those are really great shots. It is very peculiar to see it change from a gleaming gold to a dark red. Since we’re are in the bug/arachnid category in the post, can you please identify the strange looking spider in this picture: http://farm1.static.flickr.com/37/89405927_e5385823aa.jpg
I think it’s a white crab spider, but it looks very strange with that white yellow bulge.