BLUE THROUGH UV POLARIZATION SENSITIVITIES IN INSECTS - OPTIMIZATIONSFOR THE RANGE OF ATMOSPHERIC POLARIZATION CONDITIONS

A Signal-to-Noise optimization model has now been extended to explain the range of species-specific polarization sensitivities of insects. T he different polarization sensitivities are shown to represent optimiz ations for the detection of plane polarized (Rayleigh-scattered) skyli ght over a range of atmospheric polarization conditions. Rhodopsin abs orption spectra with peaks in the Blue (lambda max approximate to 450 nm) maximize detection efficiencies under conditions of high polarizat ion. Rhodopsin absorption spectra peaking in the UV (lambda max approx imate to 350 nm) maximize Signal-to-Noise Ratios for the detection of polarized skylight at the other extreme of low polarization.