[Structure of acoustic signals in the larvae of Dolihovespula wasps and Vespa crabre hornets].

Studies have been made on factors which account for the structure and noise-resistance of signals emitted by larval wasps and hornets. It was shown that temporal structure of a signal is determined by the roughness of cell walls against which the larva rubs by its mandibulae. Spectral structure of a signal depends on the size and configuration of combs. Maximum of spectral energy of each signal lies in the same frequency band from the very first up to the last impulse. This fact together with constant duration of the signal makes the latter different from other similar sounds emmitted by other members of a wasp family.