Research summary- Grinding parameters for humane slaughter of yellow mealworm larvae (Rethink Priorities)

Summary

• Grinding may be a humane method for slaughtering farmed yellow mealworm larvae. However, it is unclear what standard operating procedure producers should adopt if their machinery varies from the type used in the study.
• A single cut to any body segment rarely caused immediate death, as measured by a lack of response to mechanical stimuli, in larvae of any body size.
• By independently manipulating larval body size, particle size, plate hole diameter, and use of a filler (for the last larvae to exit the grinder), experimenters were able to assess the likelihood of instantaneous death using an industrial meat grinder.
  • The share of individuals who died instantaneously ranged from 73.27% to 96.47% depending on body size, use of filler, and particle size plate hole diameter.
  • Using a smaller plate (2.55 mm) and a filler increased the probability of instantaneous death.
• When machinery specifications differ from those used here, producers should follow directions in the supplementary materials to optimize the humaneness of their own protocol.