Look at This: Glowing South American Roaches Mimic Toxic Beetles

By Veronique Greenwood | August 23, 2012 10:25 am


Under normal light, this roach looks normal enough. But under a fluorescent light, its three spots—two large ones and one very tiny one just visible under the right spot—light up like a Christmas tree.

This remarkable species of South American cockroach, Lucihormetica luckae, owes its fluorescence to bacteria. The spots on the dark brown area of its carapace are pits inhabited by microbes that glow under fluorescent light.

A recent analysis of these creatures’ bioluminescence demonstrates that they and their cousin species glow at the same wavelengths as a toxin-producing beetle that lives in their area, suggesting that the roaches are mimicking a deadly neighbor to avoid getting picked off by predators. However, it may not be predators these roaches need to worry most about: it’s habitat destruction. No specimens have been found since the volcano they live on erupted two years ago.

Image courtesy of Vršanský et al., Naturwissenschaften (2012)

  • graeme_from_It

    looks just like EVE from Wall-E ….

  • http://www.astraean.com/borderwars/ Christopher@BorderWars

    They should name it the Ewok Roach.

  • Jeremy

    Just another Jawa.

  • http://www.revengeofthejpeg.com Gregory Urbano

    scary looking face o the head of that thing!

  • semi

    Wait. I thought this was supposed to be a science site? You do know that “bioluminescence” and “fluorescence” are two completely different things, yet this article uses the terms interchangeably. FAIL. So which is it? Are the bugs bioluminescent or fluorescent??

  • Andrew

    A Jawa was exactly what I thought too, Jeremy.

  • Ian Jamie

    semi: “Luminescence” is a catch-all term for any sort of light emission not generated by heat (e.g., incandescent bulbs, “red-hot” objects). Fluorescence is a subset of this. It refers to emission of light after excitation (irradiation) by light – most commonly experienced as (but not confined to) emission of visible light after excitation by ultraviolet light. Bioluminescence is luminescence from biological systems, hence a fluorescent, living creature is exhibiting bioluminescence.

  • hilarleo

    Well-spotted! What semi said!
    “Bioluminescence” and “fluorescence” are discrete abilities, yet this micro-article appears to use the terms indiscriminately. At least the article is confusing. But … I can dig it- “Bio-anything” is trendy.

    So then- What’s the roach doing? This article is unclear. For the sake of definitions:
    “Bioluminescence”, in conventional usage, means any biological process which generates some light, as found in certain bacteria, insects, pelagic fishes and several zooplankton. “Bioluminescence” is not dependent on or related to fluorescence and can employ all the colors of the rainbow, but often dominated by characteristic greens.
    “Fluorescence” is the enhanced, spectrum-shifted reflectivity of certain minerals and pigments. Typically mineral fluorescence appears white; But a limited range of fluorescent mineral colors are known.

    The article muddies it all, suggesting this biology depends on “fluorescent light” (which itself uses novel fluorescent processes and a variety of gas-tube environments- but not reliably producing specific wavelengths) as if every glowing thing involved mysterious fluorescent minerals.

    But our Science is alive! Humans continue to discover more more forms of luminance regularly. Knowing this- It’s the fun stuff! Not difficult. Let’s all keep it meaningful.
    And so… where now is our perfect automated Editor?


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