Hoplitis tridentata 6 prepupa with a triangularly shaped white callosity on the clypeus and a horseshoe-shaped white callosity around the anus, which both are used for sound production 7 clypeal callosity in profile distinctly projecting over the antennae (photo J. Sommerhalder) 8 anal callosity (photo J. Sommerhalder).

 
 
  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