LALL, Abner B.; CRONIN, Thomas W.; JARVILEHTO, Matti V. A.; CARVALHO, Alexandre A.; DE SOUZA, John M.; STEVANI, Cassius V.; Howard University, Washington, DC; University of Maryland, Catonsville, MD; University of Oulu, Oulu, Finland; Universidade de Sao Paulo, Sao Paulo, Brasil; Universidade de Sao Paulo, Sao Paulo, Brasil; Universidade de Sao Paulo, Sao Paulo, Brasil: Spectral Tuning Between Bioluminescence Emissions And Visual Sensitivities Among Beetles

Von Uexk�ll in 1928, proposed a functional model for instinctive behavior where the receptor and the effector systems are dovetailed to each other. An example of such a relationship both qualitative and quantitative exists among beetles. Tuning between the electroretinographic visual spectral sensitivity (VSS) and bioluminescence (BL) emission spectra of the optical signals is observed among lampyrids (10 firefly species) elaterids (4 click-beetles) and phengodid (1 rail-road worm). In situ MSP measurements show that vision is mediated by photopigments (P540 to P560) in conjunction with species specific screening pigments whose lambda maxima varies from 460 to 517 nm housed in scotopic superposition eyes adapted for night vision. The species specific screening pigments shift the VSS functions of the visual receptors towards longer wavelengths in all species and also narrow the ERG VSS among twilight-active firefly species such that the shape of the VSS and BL emissions match. These pigment screens act as noise filters to maximize signal-to-noise ratios by absorbing green foliage-reflected sunlight at dusk among twilight-active fireflies, and short wavelength space light at night among night-active beetles which possess broad green VSS functions. A mathematical optimization model based upon the efficiency for the detection of the bioluminescent optical signal in the presence of background light predict the colors of BL optical signals among fireflies.