Why do fireflies exist?

  1. EnumaElish

    EnumaElish 2,332
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    Homework Helper

    As anyone who, as a child, trapped fireflies in a glass jar could testify, fireflies' glow makes it easy to find them.

    Why isn't their glow a disadvantage when it comes to natural (detection, then) selection?
  2. jcsd
  3. Danger

    Danger 9,663
    Gold Member

    It's primarily a mating lure, as far as I know. Most likely, any predators who could see them easily are diurnal and so will be asleep when they're lit up. Bats don't count, because they can 'see' them just as well with sonar. That's just an educated guess, though.
  4. baywax

    baywax 2,002
    Gold Member

    Good guess Danger.

    its a "showy display of courtship" according to the Chronical of Higher Education.


    Here's some of the amazing facts about the fireflie's unique use of luciferin and luciferase.

  5. Danger

    Danger 9,663
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    You have a gift for making bugs interesting, Baywax. Thanks.
  6. Ouabache

    Ouabache 1,316
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    when i go outside at night, this time of year, I see a multitude of these lightning bugs across nearby open fields, many flying to the top of tall pine trees. They remind me of bioluminescent organisms I'd seen in the ocean on a evening dive.
  7. Danger

    Danger 9,663
    Gold Member

    Well, it's the same chemical reaction involved in both cases (with, perhaps, minor differences). The reasons for bioluminescence vary from one species to another, but the mechanism is the same. Squids, who are actually quite intelligent, use it for communication, angler fish use it as bait, outdoorsmen and party girls use it (in synthisized form) as glow-sticks...
  8. jim mcnamara

    jim mcnamara 1,565
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    Actually, to answer the title: 'Why do fireflies exist (implied: when it seems they should not exist)'

    Let's define improbable: 'couldn't or shouldn't exist' from my own point of view.

    When you find an improbable creature or plant: it got that way as a positive response to being able to reproduce and survive better than it's cousins who were very likely less improbable, but who may no longer be around.

    Each firefly has a species-specific flash - the males cruise around flashing, the females park on a leaf and flash greetings back. Boy meets girl.

    Except in the case of Photuris - a predatory firefly that mimics the flying/flashing behavior of male Photinus. When female Photinus flashes back a predator finds dinner(1). When Photuris are active, female Photinus became shy about flashing back. No wonder....

    (1) Kristian C. Demary and Sara M. Lewis. (2007) MALE COURTSHIP ATTRACTIVENESS AND PATERNITY SUCCESS IN PHOTINUS GREENI FIREFLIES. Evolution 61:2, 431–439
  9. baywax

    baywax 2,002
    Gold Member

    Well, you might be right. I tried to explain fireflies to Sonny Terry from out of Chicago... the famous blues harmonica player (Sonny Terry and Brownie McGee) who happens to be blind... The insects were going at their mating ritual (not unlike myself) and I said, "Sonny, the fireflies are out tonight". He wondered what I was trying to say and so did I. But I did my best to explain the wonder it makes you feel to see these lights swirling around in a place where the only electricity is feeding the stage and a few little kiosks surrounding an audience of 20,000 people. Very cool dude. Never fazed unless Browny was telling him what to do.
  10. It probably is a disadvantage, to some degree. This is one of those cases where natural selection and sexual selection can have a sort of see-saw effect on certain traits. Females can more easily see and respond to a male who flashes brightly and obviously - so that male reproduces more. But get too bright and too obvious, and those types of males get eaten before they can reproduce much. It probably goes back and forth a little bit for each successive generation. You see this is lots of animals, like male deer having very large antlers the impress the females, but take a lot of energy to make and are just damned heavy besides. Male birds with super long tails to impress females, but too long and they have trouble flying.
  11. baywax

    baywax 2,002
    Gold Member

    This survival/sexual contradiction is also evident in humans. However its often the female human who adopts disadvantageous, but effective mate-luring features like.........high heels, implants, application of carcinogenic make-ups and dyes.:rolleyes:
  12. I love fireflies on summer nights.
  13. Danger

    Danger 9,663
    Gold Member

    I don't know if the things even grow up here. I've never seen one in my life. :frown:
  14. Greg Bernhardt

    Staff: Admin

    Fireflies are quite common in SE WI in the summer months. I would agree with the above that the nocturnal predators don't rely on sight in the first place.
  15. 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.

  16. baywax

    baywax 2,002
    Gold Member

    I doubt it has to do with latitude Danger.


    Last ones I saw were in the province of Manitoba, Canada. They have severe winters there (sometimes 40 below C) but they also have flooding and a large number of lakes (over 6000) So, for a short time during summer the conditions are right for fireflies to "skip the light fantastic" even in the Great White North, eh?

    You'll notice the article mentions how the beetle uses its bioluminescence to attract prey as well as mates... Many smaller insects are attracted to light.
    Last edited: Jun 29, 2007
  17. There are 125 species of lightning bugs in the U.S. and Canada.

    Each species has their own blinking code. Females of some species mimic the codes of other lightning bugs to lure a hormone-primed male to his death.

    Ca'mer big boy!:!!)
  18. Danger

    Danger 9,663
    Gold Member

    It gets colder than that here, but not by much. The prairies are all pretty much the same. We don't, however, have any lakes around here.
    It's more likely, though, to be on account of me not being in a rural area.

    Hypatia, I'm sure that I'd have the same reaction if you flashed me.
  19. jtbell

    Staff: Mentor

    Where is "here" (at least generally)? I don't think they exist outside of North America, at least not in the countries in South America and Europe from where my college gets its native-speaker foreign language assistants. My wife is their "mother hen" while they're here, and so we have them at our house for dinner as a group occasionally. They always marvel at the fireflies when they're "in season," because they don't have them at home.

    I've always had fireflies around in the places where I've lived (Ohio, Michigan, upstate New York, South Carolina).

    You do mention prairies. Maybe fireflies need trees or similar vegetation for shelter. I've always lived in places with plenty of trees.
    Last edited: Jun 30, 2007
  20. Danger

    Danger 9,663
    Gold Member

    I'm in a town close to Calgary, but I also spent 13 years 35 miles SE of Detroit (still in Canada). I started a few miles from here, which was very rural, then moved down there in '65, then back here in '78.
  21. baywax

    baywax 2,002
    Gold Member

    I'm pretty sure you'd have seen the ICE GLOW WORMS that inhabit the frozen reaches of the Bow River then. (:uhh:)

    It's interesting they call them "glow worms". I always wondered where that name applied or came from.

    Since when is Calgary urban!!?
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