Chapter 20
Effect of Methyl Parathion on the Growth
and Reproduction of Eisenia fetida
in Natural Soil
Ankurita Nath and Subrata Hait
Abstract A laboratory study was carried out to assess the toxic effects of organophosphate insecticide methyl parathion (MP) 2% dust (active ingredient, a.i.) on
epigeic earthworm Eisenia fetida at different lethal and sub-lethal concentrations. A
series of toxicity tests starting from range finding acute to chronic were conducted in
natural soil to determine the sensitive endpoints like survival rate, growth rate and
reproduction rate of E. fetida. Results from the study revealed a reduction in the
earthworm biomass and reproduction potential. The median lethal concentration
(LC 50 ) determined from 14-day acute toxicity test was 36.63 mg a.i./kg, which
confirmed the extremely toxic nature of MP 2% dust. The addition of septic tank
sludge as a feeding material in the chronic toxicity test helped the earthworms in
gaining biomass at lower doses of 2.5 and 4.0 mg a.i./kg of MP 2% dust. At a lower
concentration in the range of (6.4–26.2 mg a.i./kg), MP 2% dust showed sub-lethal
toxicity to E. fetida. Change in the earthworm biomass and reproduction rate during
the toxicity test appeared to be the more sensitive endpoints compared to the LC 50
value used for assessing the earthworm mortality from pesticide. This study provides
an insight into the ecological risks associated with pesticides and helps to provide an
understanding of the sustainable use of pesticides for ecological protection.
Keywords Methyl parathion · Organophosphate insecticide · Eisenia fetida · Ecotoxicology · Earthworm growth and reproduction
A. Nath · S. Hait (*)
Department of Civil and Environmental Engineering, Indian Institute of Technology Patna,
Patna, Bihar, India
e-mail: shait@iitp.ac.in
© The Editor(s) (if applicable) and The Author(s), under exclusive licence to
Springer Nature Singapore Pte Ltd. 2020
S. A. Bhat et al. (eds.), Earthworm Assisted Remediation of Effluents and Wastes,
https://doi.org/10.1007/978-981-15-4522-1_20
351
Effect of Methyl Parathion on the Growth
and Reproduction of Eisenia fetida
in Natural Soil
Ankurita Nath and Subrata Hait
Abstract A laboratory study was carried out to assess the toxic effects of organophosphate insecticide methyl parathion (MP) 2% dust (active ingredient, a.i.) on
epigeic earthworm Eisenia fetida at different lethal and sub-lethal concentrations. A
series of toxicity tests starting from range finding acute to chronic were conducted in
natural soil to determine the sensitive endpoints like survival rate, growth rate and
reproduction rate of E. fetida. Results from the study revealed a reduction in the
earthworm biomass and reproduction potential. The median lethal concentration
(LC 50 ) determined from 14-day acute toxicity test was 36.63 mg a.i./kg, which
confirmed the extremely toxic nature of MP 2% dust. The addition of septic tank
sludge as a feeding material in the chronic toxicity test helped the earthworms in
gaining biomass at lower doses of 2.5 and 4.0 mg a.i./kg of MP 2% dust. At a lower
concentration in the range of (6.4–26.2 mg a.i./kg), MP 2% dust showed sub-lethal
toxicity to E. fetida. Change in the earthworm biomass and reproduction rate during
the toxicity test appeared to be the more sensitive endpoints compared to the LC 50
value used for assessing the earthworm mortality from pesticide. This study provides
an insight into the ecological risks associated with pesticides and helps to provide an
understanding of the sustainable use of pesticides for ecological protection.
Keywords Methyl parathion · Organophosphate insecticide · Eisenia fetida · Ecotoxicology · Earthworm growth and reproduction
A. Nath · S. Hait (*)
Department of Civil and Environmental Engineering, Indian Institute of Technology Patna,
Patna, Bihar, India
e-mail: shait@iitp.ac.in
© The Editor(s) (if applicable) and The Author(s), under exclusive licence to
Springer Nature Singapore Pte Ltd. 2020
S. A. Bhat et al. (eds.), Earthworm Assisted Remediation of Effluents and Wastes,
https://doi.org/10.1007/978-981-15-4522-1_20
351