Fig. 1. Spectral sensitivity curves of pigment nomograms (according to Stavenga et al., 1993), calculated for the values of maximum sensitivity of the honeybee’s ultraviolet, blue and green receptors (after Peitsch et al., 1992). Curves are normalized to a maximum value of 1.0. Similar curves are shared by many pterygote insects and possibly even the Cambrian ancestor of the mandibulates (Crustacea and Insecta).