Insect Consciousness

Defending and refining the Birch et al. (2021) precautionary framework for animal sentience

It is widely accepted that we ought to avoid taking excessive risks of causing gratuitous suffering. The practical implications of this truism, however, depend on how we understand what counts as an excessive risk. Precautionary frameworks help us decide when a risk exceeds the threshold for action, with the recent Birch et al. (2021) framework for assessing invertebrate sentience being one such example. The Birch et al. framework uses four neurobiological and four behavioural criteria to provide an evidence-based standard that can be used in determining when precautionary action to promote invertebrate welfare may be warranted. Our aim in this discussion paper is to provide a new motivation for the threshold approach that the Birch et al. framework represents while simultaneously identifying some possible revisions to the framework that can reduce false positives without abandoning the framework's precautionary objectives.

Grinding as a slaughter method for farmed black soldier fly (Hermetia illucens) larvae: Empirical recommendations to achieve instantaneous killing

At least 200 billion black soldier fly (Hermetia illucens) larvae (BSFL) are reared each year as food and feed, and the insect farming industry is projected to grow rapidly. Despite interest by consumers, producers, and legislators, no empirical evidence exists to guide producers in practicing humane - or instantaneous - slaughter for these novel mini-livestock. BSFL may be slaughtered via freezing, boiling, grinding, or other methods; however standard operating procedures (SOPs) and equipment design may affect the likelihood of instantaneous death using these methods. We tested how larval body size and particle size plate hole diameter affect the likelihood of instantaneous death for black soldier fly larvae that are slaughtered using a standard meat grinder. Larval body size did not affect the likelihood of instantaneous death for larvae that are 106-175 mg in mass. However, particle size plate hole diameter had a significant effect on the likelihood of instantaneous death, with only 54% of larvae experiencing an instant death when using the largest particle size plate (12-mm hole diameter) compared to 84% using the smallest particle size plate (2.55 mm). However, a higher percentage of instantaneous death (up to 99%) could be achieved by reducing the proportion of larvae that become stuck in the machine. We conclude by outlining specific recommendations to support producers in achieving a 99% instantaneous death rate through specific SOPs to be used with similarly designed machines. We also develop a protocol for producers that wish to test their own grinding SOPs.