Chlorination Is Ineffective at Eliminating Insects from Wastewater: A Case Study Using Ceratitis capitata

Authors: KAFUNDA, FLORA - Iowa State University; BLANCHET, ARNAUD - European Biological Control Laboratory (EBCL); DESURMONT, GAYLORD - European Biological Control Laboratory (EBCL)

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2025
Publication Date: 11/28/2025
Citation: Kafunda, F., Blanchet, A., Desurmont, G. 2025. Chlorination Is Ineffective at Eliminating Insects from Wastewater: A Case Study Using Ceratitis capitata. Insects. 16,1213. https://doi.org/10.3390/insects16121213.
DOI: https://doi.org/10.3390/insects16121213

Interpretive Summary: This study examines the effectiveness of using chlorine to eliminate insect eggs from water, specifically testing its impact on Ceratitis capitata (Mediterranean fruit fly) eggs. Eggs were exposed to various chlorine concentrations for different durations (4, 24, and 48 hours). Results showed that although high doses of chlorine exposure reduced egg hatch, it never completely eradicated eggs, even at very high doses and prolonged exposure. These results indicate that chlorination is ineffective for insect eradication from liquid waste and should be avoided due to its environmental risks. Instead, alternative methods such as heat treatment, UV exposure, and filtration are recommended for more reliable insect removal.

Technical Abstract: Eradicating insects from small bodies of water without resorting to environmentally-harmful methods is a challenge. Among the practices used to treat the water waste of arthropod containment facilities, chemical treatments such as chlorination are still commonly used, despite their known negative impacts on the environment. Here we evaluated the efficiency of chlorination to kill insects by immersing eggs of the Mediterranean fruit fly Ceratitis capitata in solutions containing different concentrations of chlorine for a duration of 4, 24, and 48h, and measuring egg hatch. Results showed that egg survivorship was negatively correlated with chlorine dose and immersion duration. However, chlorination never killed one hundred percent of insect eggs, even at extremely high doses and for a 48h immersion period, demonstrating that it is not an effective treatment method to ensure insect eradication from liquid waste. Moreover, chlorine concentrations recommended to kill microorganisms from water waste had little effect on egg survivorship. In conclusion, the use of chlorine should be avoided as a means to eliminate insects from bodies of water. More effective alternative methods such as heat treatment, UV treatment, and water filtration are preferable.