Aporrectodea caliginosa, a relevant earthworm species for a posteriori pesticide risk assessment: current knowledge and recommendations for culture and experimental design

Abstract

Ecotoxicological tests with earthworms are widely used and are mandatory for the risk assessment of pesticides prior to registration and commercial use. The current model species for standardized tests is Eisenia fetida or Eisenia andrei. However, these species are absent from agricultural soils and often less sensitive to pesticides than other earthworm species found in mineral soils. To move towards a better assessment of pesticide effects on non-target organisms, there is a need to perform a posteriori tests using relevant species. The endogeic species Aporrectodea caliginosa (Savigny, 1826) is representative of cultivated fields in temperate regions and is suggested as a relevant model test species. After providing information on its taxonomy, biology, and ecology, we reviewed current knowledge concerning its sensitivity towards pesticides. Moreover, we highlighted research gaps and promising perspectives. Finally, advice and recommendations are given for the establishment of laboratory cultures and experiments using this soil-dwelling earthworm species.

Keywords: Agroecosystems; Agroecotoxicology; Aporrectodea caliginosa; Breeding; Lumbricidae; Plant protection products; Soil ecotoxicology.

Fig. 1

World distribution map of A. caliginosa based on the literature review. Each number represents an area or a country where the species was found (see Appendix, Table S1 for the list of countries or regions and references)

Fig. 2

Number of references dealing with Aporrectodea caliginosa and Eisenia sp. and pesticides over the last 20 years (Source: ISI Web of Knowledge, using “All Databases” option, with the formula (in Topic): (pesticid* OR herbicid* OR fungicid* OR molluscicid* OR nematicid* OR insecticid* OR plant protection product* OR crop protection product*) AND (eisenia OR fetida OR foetida OR andrei) for Eisenia sp. or (caliginosa* AND earthworm*) for A. caliginosa. The search was performed in 2017 and includes references from 1996 to 2016

Fig. 3

Life cycle of A. caliginosa under laboratory conditions in a loamy field soil supplemented with horse dung milled at 1 mm as food, 15 °C, 60–70% of the soil water holding capacity (personal observations, photos ©Sylvain Bart)

Fig. 4

Steps and their duration for the culture of A. caliginosa under laboratory conditions

Fig. 5

The wet sieving method for retrieving cocoons (1-mm mesh size)