Phototransduction is the process whereby a molecule converts light into electrical signals. A case of phototransduction or photovoltaic conversion has been described in the oriental hornet Vespa orientalis (Hymenoptera, Vespinae; Fig. 23.1; Plotkin et al. 2010). Under illumination of the cuticle, the voltages measured ranged from 60 to 180 mV (Fig. 23.2). The cuticle of specimens was irradiated with monochromatic light in the 250–700 nm spectral range. The recorded light-induced voltage was on the order of 10–100 mV with maximal quantum efficiency in the 360–380 nm range (UVA). Placed back in the dark, discharge currents of several microamperes were observed (Sverdlov and Ishay 2004). Such a photoelectric phenomenon has been detected in both ether-anesthetized live hornets and dead hornets, although in the latter, the electrical values recorded were lower. The members of the colony emerge from the dark nest during the day and finally return to the nest at nightfall. Each hornet thus undergoes a daily cyclical process of electrical charging and discharging in the outer part of its integument, the cuticle, which lasts up to 30–40 min.