Spectral sensitivity of the compound eyes in two day-active fireflies (Coleoptera: Lampyridae: Lucidota).

The electroretinographic visual spectral sensitivity functions in day-active fireflies Lucidota luteicollis and Lucidota atra show a broad green sensitivity and a shoulder in the near-ultraviolet region of the spectrum as is commonly found among day-active insects. The nomogram for P530 visual pigment matches the spectral sensitivity curves in the green. The adult L. luteicollis retains its larval bioluminescent light organ which has a peak emission at 562 nm. The lambda max of the ERG spectral sensitivity does not match the bioluminescent peak as it does in twilight- and dark-active fireflies. Some relevant behavioural observations with respect to mating are presented.