Sound production in prepupae of Hoplitis tridentata. The tapping sounds (left) are produced by knocking the clypeal callosity against the cocoon wall and the stroking sounds (right) by rapidly moving the anal callosity over the cocoon wall.

 
 
  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