The spectral sensitivity of the ocellar system in the cricket Gryllus firmus (Orthoptera: Gryllidae)

In the field cricket Gryllus firmus, the electroretinographic visual spectral sensitivity functions [S(λ)] of the median and lateral ocelli show the presence of a single receptor system sensitive to the green region with a maximum at 520 nm. The S(λ) functions match the nomogram for a P520 visual pigment. The waveforms of the electroretinogram elicited by light stimuli across the spectrum are similar. The slopes of the Vlog I curves are also similar at different stimulus wavelengths across the spectrum. The ocelli are capable of responding over 3–5 log units of change in the stimulus intensity.