Challenges In Understanding Farmed Insect Welfare

Este blog ha sido traducido de Inglés a Español por Vegan Linguists. Puedes encontrar la traducción de este blog en Español aqui.

As the human population grows, more people are interested in using insects as a more sustainable source of protein. Insect welfare presents serious challenges as this new industry scales.

While some research has shown evidence of pain and suffering in insects, we still have much to learn about their subjective individual experiences. That data will be slow to come. In this paper, researchers assert that we should adopt a precautionary approach to insect welfare, instead of waiting to protect insects until we have definitive evidence of sentience. Over 1 trillion insects per year are already farmed. That number may rise to 8 trillion by 2030. By comparison, only 79 billion farmed birds and land mammals are slaughtered per year. 

The challenges of farmed insect welfare spiral out from there. The authors note that insect agriculture will have to grow rapidly to meet the potential demand for insect protein. Mass-production systems pose unique welfare concerns, such as an increased risk of insects overheating in large, high-density environments. Technological innovation, including emerging biotechnologies like genetic modification, is necessary for scaling up. Still, the paper notes that new technologies can create new welfare problems. Currently, only a small percentage of edible insect species are farmed, but if insect agriculture expands, more species may be used in agriculture. Each individual insect species has their own needs, and accurately characterizing the welfare needs of each species will be difficult.

The authors also note that existing welfare assessment tools may not work for insects because their physiological and behavioral needs are different from farmed land animals’ needs. For example, it is difficult to estimate pre-slaughter mortality in insects, because individuals may cannibalize the entire bodies of dead insects. Temperature variations matter more for insects, who are cold-blooded, than for mammals or birds.

Given the difficulty in estimating what insects may feel, the researchers say that housing and management systems should be designed using the Five Domains Model, which uses physical markers (such as nutrition and physical health) as rough indicators of mental states. The Five Domains Model may measure insect welfare more effectively than the traditional Five Freedoms model, which requires that we have information about the animal’s internal states that we simply don’t have for insects. 

Genetic drift, the change in frequency of a gene in a population by random chance, occurs naturally in isolated animal populations, especially in artificially isolated insect populations. Therefore, the researchers say, farmed insect populations may evolve to have different needs than the laboratory populations animal welfare scientists study. In addition, the range of individual traits within an insect population makes it challenging to create standardized assessments that guarantee high welfare for all insects. As in other species, different insect individuals have different preferences and needs.

Unlike terrestrial animals, insects begin life as larvae and change into other forms until reaching their final adult form, a complex process called metamorphosis. Metamorphosis is different for all insect species, and our understanding of cognitive processes at each life stage is limited. Even if we understand the needs of adults, the authors assert that the needs of larva may be very different.

Advocates will have to determine appropriate trade-offs between species. For example, some insects are farmed for use in fishmeal. If insects aren’t farmed, then fishers will catch wild fishes for fishmeal instead. It takes more insect individuals to produce the same amount of fishmeal, but fishes may be more sentient than insects. We currently lack a principled way to make such trade-offs or assessments. The authors assert that sentience and the total number of farmed individuals are important assessments when making decisions involving different species. 

We need research that addresses these challenges. Stakeholders need to collaborate, because farmers and entomologists lack guidance on how to address ethical concerns, while welfare biologists and animal ethicists lack insect-specific and industry-specific knowledge. While borrowing theoretical models from the vertebrate welfare literature may be helpful, all borrowing must take into account insects’ specific needs. Insect welfare tools developed in labs may not address industry-specific welfare problems. As this issue progresses, the authors say we must frequently change insect welfare assessment tools in response to changes in industry practices, which insect species are farmed, and the genetics of farmed insect populations.