Treading Lightly

Insect eyes, much different from human eyes, are sensitive to polarized light, especially of the horizontal variety -- the kind of light reflected off of bodies of water when the sun hit them. It is known that insects sometimes lay their eggs on glass buildings and other highly reflective surfaces, and these surfaces become ecological traps associated with reproductive failure and mortality. So the researchers decided to test if solar panels, very reflective devices, act in a similar beguiling way. The scientists used imaging polarimetry and measured reflection-polarization characteristics of various types of solar panels when they were presented to mayflies (Ephemeroptera), caddisflies (Trichoptera), stoneflies (Plecoptera), dolichopodid dipterans (Diptera), and tabanids (Tabanidae). They found that at a certain angle (the Brewster angle) solar panels reflect polarized light almost completely. Mayflies, stoneflies, dolichopodids, and tabanids were found to be the most attracted to solar panels. Based on this result, they then tested different panel designs and found that aquatic insects are less attracted to solar panels that have a white borders and white grids, 10-26 fold less attracted. This research highlights the need to research more into solar panel design and placement in the environment.

Here's the paper:
Horváth, G. et al. (2010). Reducing the maladaptive attractiveness of solar panels to polarotactic insects. Conservation Biology (DOI: 10.1111/j.1523-1739.2010.01518.x)

(image from http://lhalter.files.wordpress.com/)