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Why do fireflies glow?
One reason that fireflies glow is to attract a
mate. Males and females of the same species will flash
signals back and forth as a way of communicating. Each
firefly species has its own particular pattern. For example,
the fireflies of one species will fly around in the night sky
and dive steeply just as the flash begins and turn upward to make a
distinctive J-shaped pattern of light.
Female fireflies hang out on a tree branch or in the
grass while the males fly around showing off their best
flashes. When a female recognizes the flash from a male of
the same species, she will answer with her best flash.
Another reason that fireflies glow is to avoid
predators. Fireflies are filled with a nasty tasting
chemical called lucibufagens, and after a predator gets a mouthful, it
quickly learns to associate the firefly's glow with this bad
taste! So not only does the flashing help attract a mate, but
it also warns predators to stay away.
One species of firefly that can't make its own lucibufagens acquires it by eating others that can. To lure victims, these fireflies mimic the flashing pattern of another species. When the unsuspecting male approaches to find a mate, he instead becomes a tasty treat to the tricky firefly.
Genetic Science Learning Center. (2016, March 1) What Makes a Firefly Glow?.
Retrieved October 19, 2021, from https://learn.genetics.utah.edu/content/basics/firefly/flash
What Makes a Firefly Glow? [Internet]. Salt Lake City (UT): Genetic Science Learning Center; 2016
[cited 2021 Oct 19] Available from https://learn.genetics.utah.edu/content/basics/firefly/flash
Genetic Science Learning Center. "What Makes a Firefly Glow?." Learn.Genetics.
March 1, 2016. Accessed October 19, 2021. https://learn.genetics.utah.edu/content/basics/firefly/flash.