Monday Moth: White-tipped Black Moth

Melanchroia_chephise_IMG_1241_1200x800_enh

Photo details: Canon 100mm macro lens on Canon 50D (manual mode), ISO-100, 1/250 sec, f/22, MT-24EX flash w/ Sto-Fen diffusers.

When is a ctenuchid moth not a ctenuchid moth?  When it’s a White-tipped Black Moth (Melanchroia chephise) in the family Geometridae!

I may be a beetle guy, but I also consider myself a competent general entomologist.  What is a competent general entomologist?  Someone who can identify any insect to order at first glance and a majority of them to family – regardless of one’s own taxa of expertise.  Thus, when I encountered this mating pair of moths on the outside wall of my sister-in-law’s condominium in Seminole, Florida, I “recognized” them as something in what I learned as the family Ctenuchidae (later subsumed within the Arctiidae, first as a subfamily and now as several disparate tribes).  They had all the hallmarks of ctenuchids—black and red coloration, narrowish wings with light colored patches, and about the size of the wasps that they presumably mimic.  Upon my return to St. Louis, I sat down to identify the moths—confident that their distinctive appearance would lead to the quick ID that never materialized after scanning through all of the ctenuchine pages at BugGuide.  Frustrated, I resorted to posting the photo on the site’s ID Request, never questioning my ctenuchine placement.  Precisely 4 minutes later, the moths were identified by John Maxwell as Melanchroia chephise and moved to their proper place—among the 50 other adult photographs of this species that can be found on the site!  I might as well have failed to identify a monarch butterfly!

Melanchroia chephise is apparently common in the American tropics, reaching its northern distributional limit along the coastal plains of Florida and Texas but straying further north in certain years.  Larvae feed on several plants in the family Euphorbiaceae, primarily Breynia and Phyllanthus species.  The adult coloration strikes me as obviously aposematic (warning coloration), but I could find no specific references to this.  However, considering that euphorbiaceous plants are famous for their diverse arsenal of latex and irritant toxins (e.g., diterpene esters, alkaloids, glycosides, ricin-type protein toxins, etc.), it seems reasonable to presume that Melanchroia larvae have evolved mechanisms for sequestering one or more of these compounds.  NABA South Texas states that adults of this species are probably mimics of the Red-bordered Pixie (Melanis pixe), an aposematic metalmark butterfly also of Neotropical distribution that reaches south Texas (but not Florida).  Personally, I don’t really see the resemblance (but then, nor am I an avian predator).  I suppose it’s possible that a species such as this can employ different defense strategies in different parts of its range, relying on Batesian mimicry in areas where suitable models occur and aposematism in areas where they don’t, but I have to admit that I’m now straying well outside the coleopteran-centric bounds of my expertise.

Copyright © Ted C. MacRae 2009

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About Ted C. MacRae

Ted C. MacRae is a research entomologist by vocation and beetle taxonomist by avocation. Areas of expertise in the latter include worldwide jewel beetles (Buprestidae) and North American longhorned beetles (Cerambycidae). More recent work has focused on North American tiger beetles (Cicindelidae) and their distribution, ecology, and conservation.
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19 Responses to Monday Moth: White-tipped Black Moth

  1. Crystal says:

    My first thought was “looks like Ctenucha virginica”…fooled me too. I agree that it doesn’t look like M. pixe either, at least not more than very superficially; I’ll join you on the “safe to presume sequestration” bandwagon.

  2. jason says:

    “I might as well have failed to identify a monarch butterfly!” I laughed uproariously at that. Ever seen a viceroy? Well, they don’t really look like monarchs as far as I’m concerned, but your statement reminded me of Alex’s post on the mimic issue. Thanks for the chuckle.

    The photo is gorgeous, as are the subjects! And I like images that show the more intimate side of nature (i.e. critters gettin’ to know each other in the biblical sense). Being a prude isn’t my thing.

    Cool learning experience. I know a lot less than you about insects, so I pretty much feel certain I would have made a similar mistake trying to ID them. (At least now I can always point and say, “Well, he did it too, and he’s a lot smarter than me!”)

    • jason says:

      BTW, the ‘subscribe to comments’ function seems to be broken. Each time I leave a comment and check the box, I get an e-mail saying I have to click a link to confirm that I want to receive notices for future comments on that post. It happens for every post I comment on. But when I click the links, I’m asked to login with a wordpress.com ID and password so I can confirm. Strange… (Or is it just me? That would not surprise me in the least!)

    • I’m with you – photos that reveal aspects of behavior and biology are much more interesting. If you like bug love, you’ll enjoy the photos in my post, Oklahoma is for lovers.

  3. Wilma Lingle says:

    Great story, Ted. The detail in the photo is superb. I hope I can remember the “moral” of the story when I next get fixated on an ID.

  4. Phil Koenig says:

    Those who know better sometimes even confuse Monarchs and Viceroys. The Idalia Soc. occasionally has specimens donated by collectors and offered for a donation to benefit the society. I found a diminutive Monarch that had been passed off as an unwanted Viceroy and snatched it up. We all make mistakes but it is admirable when we are willing to admit it.

    Phil

    • Hi Phil – well, I don’t feel too bad about it, since I am, afterall, a coleopterist. I would have a hard time ‘fessing up if I was a lepidopterist and mis-ID’d a monarch as a viceroy!

  5. Mike Quinn says:

    Ted, Your bug can be common along the Texas coastal plains primarily from September through December. (See link.) In 2007, strays were recorded from Arizona, Oklahoma, Arkansas, Kansas and even southern Illinois!
    Mike Quinn, Austin

  6. Leslie says:

    I came across this beautiful moth this morning while walking my dog on my property. I’ve never seen one before, and so I “Googled” it and now I know what it’s called. Strange tho’ – seems since 2009 it may be straying further west, as I live on the Sonoma Coast (Northern California) about 1200′ above the Coast Highway. Lots of evergreen and redwoods – are they destructive?

    • This moth occurs in the US along the Gulf Coast from Florida to Texas. It can stray further north in some years, but I’ve not heard of it reaching California – I suspect you saw something else, but I’m not really a moth person so I can’t give any suggestions. Do you have a photo?

      • Leslie says:

        Hi Ted –
        Thanx for getting back to me. I don’t have a photo – I tried to bring it home with me to photograph (a few times – it flew further into the tall grasses each time until I lost it). But it definitely was a white-tipped black as I had never encountered a moth with such color distinctions of black, red, a most intense blue and the tiny white tips on the bottom edge of the wings – it was most beautiful! But I worry if it is destructive as I have many fir, tan oak and redwood trees on the property. Anyhow, I’m taking my camera with me tomorrow morning just in case!
        Leslie

        • That doesn’t sound like any ‘destructive’ moth that I’m aware of – I think you can relax and enjoy its beauty.

          • Leslie says:

            Hi Ted –
            I saw two more yesterday late afternoon at a friend’s property about 3 miles down the road. She thought they were beautiful too and had never seen one before. I tried to catch one to bring home to photograph – to no avail. I’ll be taking my camera everywhere from now on; I’m determined now to capture a photo of this unusual moth! I’ll send you a pix if I’m successful. Thanx for all your input –
            Leslie

            • If you do get pics, I suggest submitting them to BugGuide.com – you’ll get an answer there for sure, probably within minutes!

              • Leslie says:

                Thanx Ted – I’ll do just that. Saw two more yesterday but wasn’t able to get a picture. And I was told they’ve been seen down in the State Park (Fort Ross); sea level. I have two friends now that have seen them and they are going to try and capture one for me to photograph. Gee – what an adventure this is turning out to be!

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