Modelling the effects of the pyrethroid insecticide cypermethrin on the life cycle of the soil dwelling annelid Enchytraeus crypticus, an original experimental design to calibrate a DEB-TKTD model

Sylvain Bart; Tjalling Jager; Stephen Short; Alex Robinson; Darren Sleep; M Glória Pereira; David J Spurgeon; Roman Ashauer

doi:10.1016/j.ecoenv.2023.114499

Modelling the effects of the pyrethroid insecticide cypermethrin on the life cycle of the soil dwelling annelid Enchytraeus crypticus, an original experimental design to calibrate a DEB-TKTD model

Ecotoxicol Environ Saf. 2023 Jan 15:250:114499. doi: 10.1016/j.ecoenv.2023.114499. Epub 2023 Jan 5.

Authors

Sylvain Bart¹, Tjalling Jager², Stephen Short³, Alex Robinson³, Darren Sleep⁴, M Glória Pereira⁴, David J Spurgeon³, Roman Ashauer⁵

Affiliations

¹ Department of Environment and Geography, University of York, York YO10 5NG, UK; UK Centre for Ecology and Hydrology, Wallingford OX10 8BB, UK; MO-ECO2 (Modelling and Data Analyses for Ecology and Ecotoxicology), Paris, France. Electronic address: sylvainbart.moeco2@gmail.com.
² DEBtox Research, Stevensweert, the Netherlands.
³ UK Centre for Ecology and Hydrology, Wallingford OX10 8BB, UK.
⁴ UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, UK.
⁵ Department of Environment and Geography, University of York, York YO10 5NG, UK; Syngenta Crop Protection AG, Basel 4058, Switzerland.

PMID: 36610295
DOI: 10.1016/j.ecoenv.2023.114499

Abstract

The Dynamic Energy Budget theory (DEB) enables ecotoxicologists to model the effects of chemical stressors on organism life cycles through the coupling of toxicokinetic-toxicodynamic (TK-TD) models. While good progress has been made in the application of DEB-TKTD models for aquatic organisms, applications for soil fauna are scarce, due to the lack of dedicated experimental designs suitable for collecting the required time series effect data. Enchytraeids (Annelida: Clitellata) are model organisms in soil ecology and ecotoxicology. They are recognised as indicators of biological activity in soil, and chemical stress in terrestrial ecosystems. Despite this, the application of DEB-TKTD models to investigate the impact of chemicals has not yet been tested on this family. Here we assessed the impact of the pyrethroid insecticide cypermethrin on the life cycle of Enchytraeus crypticus. We developed an original experimental design to collect the data required for the calibration of a DEB-TKTD model for this species. E. crypticus presented a slow initial growth phase that has been successfully simulated with the addition of a size-dependent food limitation for juveniles in the DEB model. The DEB-TKTD model simulations successfully agreed with the data for all endpoints and treatments over time. The highlighted physiological mode of action (pMoA) for cypermethrin was an increase of the growth energy cost. The threshold for effects on survival was estimated at 73.14 mg kg^{- 1}, and the threshold for effects on energy budget (i.e., sublethal effects) at 19.21 mg kg^{- 1}. This study demonstrates that DEB-TKTD models can be successfully applied to E. crypticus as a representative soil species, and may improve the ecological risk assessment for terrestrial ecosystems, and our mechanistic understanding of chemical effects on non-target species.

Keywords: Annelida; DEBtox; Effect modelling; Energy budget; Environmental risk assessment; Potworms; Toxicokinetic-toxicodynamic modelling.

MeSH terms

Animals
Ecosystem
Insecticides* / toxicity
Life Cycle Stages
Oligochaeta*
Pyrethrins* / toxicity
Research Design
Soil

Substances

cypermethrin
Insecticides
Soil
Pyrethrins