Dragonfly Again

Yesss! I have witnessed a real biological phenomenon!
I wrote last week about seeing a dragonfly zooming around the roof of a dark car. Now I just read in Science magazine that that really happens.

"Ever since 1998, the year the water-beetle journal Latissimus published a landmark paper entitled 'Another case of water beetles landing on a red car roof,' entomologists have sought to understand why aquatic insects tend to lay their eggs on dark-colored vehicles.

Now a Hungarian team explains why. Biophysicist Gabor Horvath and colleagues of Eotvos Lorand University in Budapest laid out red, black, yellow, and white plastic sheets by a marsh one sunny summer day. Over the course of 3 hours, 1229 aquatic insects landed on the sheets: 700 on the red and 398 on the black, but only 88 on the yellow and 43 on the white. The scientists then measured reflection and polarization patterns from four automobiles in the same colors.

The secret? Aquatic insects detect water based on the horizontal polarization of reflected light. Light from the red and black cars was highly and horizontally polarized, so from a bug's point of view, the darker surfaces look like water, the team concludes in the 7 July issue of Proceedings of the Royal Society B.

'We propose that visitors to wetland habitats drive light-colored cars to avoid egg loss by confused water insects,' the team wryly advises."

I get such a kick out of seeing things in the natural world and understanding why they're happening. Sometimes I think I missed my calling as a research scientist. I had the opportunity to go that route, and lots of encouragement. The specificity of the focus and the monotony of the routine turned me off though. I am really more of a naturalist.