Dragonfly Death Traps

May 1, 1996 5:00 AMNov 12, 2019 6:12 AM


Sign up for our email newsletter for the latest science news

When Iraqi forces finally pulled out of Kuwait in 1991, they left in their wake hundreds of blown-up oil wells and pipelines. Much of the spilled oil still pollutes the Kuwaiti desert, in the form of oil lakes and ponds. These oil lakes have proved to be a death trap for water-seeking insects like dragonflies. The reason: To insects, oil looks more like water than water itself. Biophysicist Gábor Horváth of the University of Tübingen in Germany and his colleague Jochen Zeil, a biologist then at Kuwait University and now at the Australian National University, studied how the oil pools reflect light. Light reflecting from both water and oil is partially polarized--that is, the light waves reflecting from these liquids vibrate at a distinct angle. Insects, unlike humans, can see polarized light and use it to find water. In fact, says Horváth, the oil surface is more polarized than the water surface, and therefore oil is more attractive to insects. He has found that oil can trap 25 times more dragonflies than water. A small oil pond could trap thousands of dragonflies when they are swarming, Horváth says, and nobody has studied yet what impact that would have on the insect population.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.