Fig. 1. (A) Spectral reflectance of stimuli (1=100%). (B) Spectral sensitivities of the photoreceptors of Deilephila elpenor assuming fused rhabdoms containing all three photoreceptor types. UV, B and G refer to the photoreceptors with peak absorption wavelengths of 350, 440, and 525 nm, respectively. Solid lines show normalized receptor sensitivities that were used to calculate relative quantum catches. The broken line shows the sensitivity of the green receptor that was used for the achromatic contrast calculations.