24 votes

Why flying insects gather at artificial light

4 comments

  1. Happy_Shredder
    Link
    As a side note, apart from the great research, I love the figures in this paper. They're so clear and concise, and appropriately pretty. Reducing 500 videos to a handful of figures is a huge task...

    As a side note, apart from the great research, I love the figures in this paper. They're so clear and concise, and appropriately pretty. Reducing 500 videos to a handful of figures is a huge task - great scientific communication!

    7 votes
  2. updawg
    Link
    So it's not that more bugs fly there, it's just that bugs get trapped in the general area of the lights? Also, I'm not going to read this entire paper, but it seems like the bugs would orbit the...

    Abstract
    Explanations of why nocturnal insects fly erratically around fires and lamps have included theories of “lunar navigation” and “escape to the light”. However, without three-dimensional flight data to test them rigorously, the cause for this odd behaviour has remained unsolved. We employed high-resolution motion capture in the laboratory and stereo-videography in the field to reconstruct the 3D kinematics of insect flights around artificial lights. Contrary to the expectation of attraction, insects do not steer directly toward the light. Instead, insects turn their dorsum toward the light, generating flight bouts perpendicular to the source. Under natural sky light, tilting the dorsum towards the brightest visual hemisphere helps maintain proper flight attitude and control. Near artificial sources, however, this highly conserved dorsal-light-response can produce continuous steering around the light and trap an insect. Our guidance model demonstrates that this dorsal tilting is sufficient to create the seemingly erratic flight paths of insects near lights and is the most plausible model for why flying insects gather at artificial lights.

    So it's not that more bugs fly there, it's just that bugs get trapped in the general area of the lights?

    Also, I'm not going to read this entire paper, but it seems like the bugs would orbit the lights. Why does it seem like they don't fly around back?

    5 votes
  3. NickyPants
    Link
    That's a pretty awesome proof. The most common justification given in my entomology classes just a few years ago had to do with celestial navigation interference. Either way, completing our insect...

    That's a pretty awesome proof. The most common justification given in my entomology classes just a few years ago had to do with celestial navigation interference. Either way, completing our insect collections would have been significantly harder without a black-light and white sheet. Cool to know a solid justification for why.

    2 votes
  4. doingmybest
    Link
    This is cool. So it seems like the old “moon navigation” theory is sort of right. But insects use light from the sky is an indicator of “up”. So if you tilt your top toward the light, you will on...

    This is cool. So it seems like the old “moon navigation” theory is sort of right. But insects use light from the sky is an indicator of “up”. So if you tilt your top toward the light, you will on average tend toward the light source if it is not, in fact coming from true the sky.