Fig. 6. (A,B) Mean (± S.E.M.) colour contrasts of different body parts of melanic Nephila pilipes viewed by achromatic and chromatic vision. Broken lines indicate the threshold for colour-contrast detection estimated for honeybees. (C,D) Schematic drawings mimicking the (C) dorsum and (D) ventrum patterns perceived by bees using chromatic vision following scenarios used in Fig. 5.