Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2021
Publication Date: 8/18/2021
Citation: Burgess, E.T., Taylor, E.E., Acevedo, A., Tworek, M., Nayduch, D., Khurana, N., Miller, J.S., Geden, C.J. 2021. Diets of Erythritol, Xylitol and Sucrose affect the digestive activity and gut bacterial community in adult house flies. Entomologia Experimentalis et Applicata. https://doi.org/10.1111/eea.13088.
DOI: https://doi.org/10.1111/eea.13088

Interpretive Summary: Control of house flies is a global problem because of high levels of insecticide resistance. Recent research has demonstrated that flies are killed when they feed on the artificial sweeteners erythritol and xylitol, which are safe for humans and the environment. The reason for their toxicity to insects has been an open question. In this paper, scientists at Northern Illinois University and USDA-ARS in Gainesville, FL, and Manhattan, KS examined several possible explanations for the toxicity of these sweeteners for house fly. The possible mechanisms included 1) dehydration from excessive regurgitation; 2) arrestment of physiological processes due to abnormally high hemolymph osmolality or osmotic diarrhea; and, 3) reduction of the gut microbiome. The results showed that flies die from complications caused by excessive vomiting after consuming the sweeteners. This work supports the continued evaluation of these safe materials as a tool for house fly control where insecticides are no longer effective or for use in organic production systems.

Technical Abstract: Polyol sweeteners, including erythritol and xylitol, have been investigated for their potential insecticidal actions against a number of insect pests including mosquitoes, fruit flies and filth flies. Several insecticidal modes of action for the polyols have been proposed in non-biting flies and include: 1) dehydration from excessive regurgitation; 2) arrestment of physiological processes due to abnormally high hemolymph osmolality or osmotic diarrhea; 3) reduction of the gut microbiome. Here we explored the proposed modes of action in the house fly, a non-biting fly of medical and veterinary importance. House flies regurgitated at a significantly higher rate when fed erythritol or xylitol compared to sucrose, both when the polyols were presented in solutions or dry. The highest hemolymph osmolality was observed in flies fed sucrose solutions, who also deposited significantly more fecal spots than flies fed polyol solutions. Cultivable bacteria were least abundant in the sucrose solution-fed flies and most abundant in control flies provided water only. Of the tested hypotheses, complications from excessive post-feeding regurgitation seem likeliest to cause death after polyol consumption. Benefits of polyols as components to house fly control products are discussed.