Identifying trends in reporting on the ethical treatment of insects in research

Abstract

Transparent reporting on the ethical treatment of research animals (e.g., implementation of the 3Rs, replace, reduce, and refine) is recommended when publishing in peer-reviewed literature. This is meant to foster public trust, safeguard animal welfare, and generate reproducible science. However, entomologists are not expected to engage in such reporting, as their research is not subject to legislated ethical review. Recently, however, entomologists have reported increased concern about the ethical treatment of insects in research, and associated reproducibility and public trust issues. To what degree are these increasing concerns reflected in changes in practices? We surveyed 15 high-impact journals that publish on insects over 20 years to collect data on reporting related to the ethical treatment of insects in research, including animal reduction methods, analgesics/anesthesia statements, and information regarding sacrifice. Out of 1359 sampled papers, no studies reported any methods to reduce animal use. Over 20 years, we found an increase in the proportion of papers reporting insect death and a decrease in the papers reporting significant invasive handling. 84% of papers with significant animal handling or death did not report the use of any anesthetics. We also found an increase in animal-treatment-specific ethics statements (from 0% to 8%), largely driven by the journal Animal Behaviour. We end by 1) making recommendations for entomologists looking to improve their reporting practices and 2) providing tools to improve transparent reporting of information related to the ethical treatment of insects in research.

Fig 1. The percentage of studies that resulted in insect death increased over time.

There was a significant increase in the proportion of studies containing insect death (with or without handling) over time (linear regression; t_20,18 = 2.33, p = 0.031, R² = 0.23). There was a significant decrease in the proportion of studies reporting just invasive handling (without death) over time (linear regression; t_20,18 = 4.00, p = 0.001, R²= 0.44). There was no change in the percentage of studies containing death only (no handling), both death and significant handling, or neither death nor significant handling (linear regression; t_20,18 < 1.19, p > 0.05).

Fig 2. The percentage of studies that contained an ethics statement increased over time, largely driven by Animal Behaviour.

There was a significant increase in the proportion of studies containing an ethics statement over time (green line; general linear model, quasibinomial family, t_20,18 = 4.35, p < 0.001). Much of this increase in the use of ethics statements was driven by publications in Animal Behaviour, however even with this journal excluded there was still a significant increase from 0.00% in 2003 to 1.35% in 2022 in the proportion of studies containing an ethics statement in the other 14 journals (black line; general linear model, quasibinomial family, t_20,18 = 2.40, p = 0.03).

Fig 3. The journal Animal Behaviour has a greater proportion of papers with an ethics statement than any other journal.

(A) None of the other 14 journals, excluding Animal Behaviour, have a significantly different proportion of papers with ethics statements from each other (ANOVA, F = 1.29, p = 0.22). Journal abbreviations: ASaD - Arthropod Structure and Development; EE – Ecological Entomology; IBaMB - Insect Biochemistry and Molecular Biology; IS – Insect Science; JEB – Journal of Experimental Biology, JoIP – Journal of Insect Physiology; JoPS – Journal of Pest Science; MaVE – Medical and Veterinary Entomology; Nature – Nature; PNAS – Proceedings of the National Academy of Sciences; ProcB: Proceedings of the Royal Society B; ICaD - Insect Conservation and Diversity; JIFF – Journal of Insects as Food and Feed; eLife - eLife. (B). The journal that requires an ethics statement for studies that use invertebrates (Animal Behaviour) has a higher mean proportion of papers with an ethics statement compared to journals that do not require an ethics statement for studies that use invertebrates.

Fig 4. The percentage of papers reporting relevant anaesthesia or sacrifice statements by journal taxonomic scope.

(blue) Journals that publish vertebrate research as well as invertebrate research had a significantly higher proportion of papers reporting an anaesthesia or analgesia statement compared with journals that publish only invertebrate research (t-test, t_40,3= 3.19, p < 0.003). (black) Journals that publish vertebrate research also had a significantly higher proportion of papers reporting a sacrifice statement compared with journals that publish only invertebrate research (t-test, t_40,38 = 3.05, p < 0.005).

Fig 5. Percentage of studies with an anaesthetic or sacrifice statement prior to handling or death by order.

Left) Percentage of studies with an anaesthetic statement prior to handling varied by order. Letters indicate statistically significant differences between orders. Middle) There was no significant difference in the percentage of studies with an anaesthetic statement prior to death among orders. Right) There was no significant difference in the percentage of studies with a sacrifice statement prior to death among orders.