Acoustic communication in Neoponera villosa (Hymenoptera, Formicidae, Ponerinae)
Bioacoustics; stridulation; drumming; social insects; ants; castes.
Acoustic and vibratory signals are used by several ant species in intraspecific and interspecific interactions, although studies concerning these signal modalities are scarce. Stridulation and drumming are among the main ways of producing vibroacoustic signals. These signals can transmit messages relative to alarm, distress, recruitment, attack, colony activation, clues for provisioning of larvae, evaluation of food resources and non-receptivity of females. The aim of this study was to investigate the use of acoustic signals in Neoponera villosa (Hymenoptera, Formicidae, Ponerinae). In order to achieve our aim, we characterized workers, gynes and males stridulation; we analyzed N. villosa colonies’ response to workers’ stridulation and evaluated the acoustic response of N. villosa colonies to nest disturbance. The results showed that stridulatory signals of N. villosa workers are composed mainly of monosyllabic chirp trains, with chirps composed of a single sequence of pulses. Nevertheless, the majority of the chirps produced by the reproductive castes presented a low amplitude pulse sequence preceding the main high amplitude sequence of pulses. These chirps were composed of two subunits and, thus, were identified as disyllabic chirps. The stridulatory signals presented significant differences among the N. villosa castes regarding the inter-chirp interval, the number of pulses per chirp, the inter-pulse interval and the pulse repetition rate. When exposed to workers’ stridulation, N. villosa colonies responded to the emission of stridulatory signals with behavioral pattern changes only if these acoustic signals were produced by nestmates. In nest disturbance context, N. villosa colonies did not respond with stridulatory signal emission, but with the emission of acoustic signals produced by drumming.