Scientists Figure Out How -- and Why -- This Cockroach Glows in the Dark

This cockroach is not your everyday insect to scurry out from under the refrigerator or one that elicits startled shrieks when you turn on the bathroom light. In fact, you wouldn't have to even turn on your light to see this one coming.

It's a South American cockroach, Lucihormetica luckae, that Discover Magazine reports was recently studied by scientists for its ability to glow in an effort to explain how bioluminescence began on land (it is more common in marine mammals).

In studying the bio-luminescent qualities of terrestrial organisms, the researchers restricted their study to 13 species of luminescent cockroaches and found the "photo-characteristics" of three of them mimic that of a toxic click beetle.

Similar in concept to the non-toxic Viceroy butterfly, which mimic's the look of the toxic Monarch butterfly, this cockroach mimics the same effect of a toxic click beetle so it does not get eaten.

"These observations are the evidence for the mimicry by light—a new type of defensive, Batesian and interordinal mimicry," the researchers write in the study abstract. "Our analysis surprisingly reveals an evolutionary novelty of all living luminescent insects, while in the sea (and possibly in the soil) luminescence is present also phylogenetically in very primitive organisms."

Discover Magazine explains that the back of the cockroach is full of "pits inhabited by microbes."

New Scientist reports Peter Vršanský, a palaeobiologist at the Slovak Academy of Sciences in Bratislava, as saying that with this evidence alluding to a more modern emergence of terrestrial animals to bioluminescence, most likely from one ancestor, it "suggests they are extremely rare and vulnerable to extinction."

Science Magazine reports habitat destruction could be a greater threat than predators though -- one that it's glow won't have any effect upon:

The only known specimen of the insect was collected in 1939 on the slopes of Ecuador’s Tungurahua volcano, and the site was damaged when the peak erupted in December 2010.

For a bit of fun, io9 thinks a Star Wars character may be borrowing from the cockroach's look. It calls the comparison between the cockroach and jawas (pictured below) "uncanny...right down to the little bandolier."

(H/T: Daily Mail)