Thermo- and photoelectric current in hornet cuticle

Thermoelectric and photoelectric currents were measured in the cuticle of hornets. The spontaneous current in the studied specimens ranged between 30-40 nAmp under conditions of darkness whereas under illumination the current drops to near zero. Upon warming up to 28-29 degrees C, the current rises to 50-200 nAmp but subsequently, after a while, it declines, regardless of whether the temperature is held steady, continues to rise or is lowered. In light, the current values are lower than in darkness and this under all conditions. When the specimen is charged with an electric current under fixed temperature, the current attains several microAmp in darkness but is usually less than that under illumination by about one order of magnitude. The capacitance values range between 1-7 mFarad both in light and in the dark. Possible mechanisms for creating this cuticular current and the changes which it undergoes under the various experimental conditions are discussed, and so also the properties of hornet cuticle as a semiconductor and possible applications of the described phenomena in everyday life of hornets.