Amplitude plot (above) and spectrogram (below) of a prepupal stroking sound of Hoplitis tridentata of 46 ms duration containing 15 syllables; the sounds were recorded with a batlogger in a distance of 20 cm from the opened nest stem.
Part of: Müller A, Obrist MK (2021) Simultaneous percussion by the larvae of a stem-nesting solitary bee – a collaborative defence strategy against parasitoid wasps? Journal of Hymenoptera Research 81: 143-164. https://doi.org/10.3897/jhr.81.61067