Demography of Paronychiurus kimi (Lee) (Collembola : Onychiuridae) under the influence of glufosinate-ammonium on plaster charcoal substrate and in artificial soil

The demography of Paronychiurus kimi (Lee), a dominant springtail in the pa ddy fields of Korea, was studied under the influence of glufosinate-ammoniu m (GA), a herbicide, on two different substrates: plaster-charcoal and arti ficial soil. On plaster-charcoal substrate with brewer's yeast provided as food, survival rate of eggs, juveniles and adults, and life table statistic s of P. kimi did not reveal any significant influence of GA except at an ex tremely high concentration (1572.70 mug/cm(2)). The EC50 of GA for reproduc tion of P kimi was estimated to be 446.21 mug/cm(2). In artificial soil wit h brewer's yeast, P. kimi was susceptible to GA. Reproduction of P. kimi wa s significantly reduced at 0.5 mg/kg and the adult survival rate decreased at 50 mg/kg. The life table statistics showed significant influences of GA even at low concentration, and the EC50 was estimated to be 0.039 mg/kg. Th e fact that acute toxicity of GA to the springtail is negligible does not g uarantee negligible impact of the herbicide on springtail populations in th e field. (C) 2001 Elsevier Science B.V. All rights reserved.