A staged approach using ants as test organism in ecotoxicology

Abstract

Although ants (Hymenoptera: Formicidae) are ecological key components, they are currently not included in ecotoxicity testing. Based on their social organization, ecology and exposure routes to pesticides, we propose a multilevel testing scheme for ants starting from isolated workers (level-1), workers and brood (level-2) and founding queens or entire colonies (level-3). To evaluate feasibility, we tested three ant species (Camponotus maculatus, Crematogaster sp., Lasius niger) using the neonicotinoid imidacloprid as a test substance. Ants were orally exposed through liquid food. At level-1, worker survival showed a clear concentration response and allowed to estimate LC50 with sufficiently narrow confidence intervals. In level-2, worker mortality and sublethal effects negatively affected larval survival and development, e.g. occurrence of naked pupae, with a lower NOEC for larvae ( View larger version (28K): org.highwire.dtl.DTLVardef@11387feorg.highwire.dtl.DTLVardef@1456368org.highwire.dtl.DTLVardef@8171b5org.highwire.dtl.DTLVardef@504536_HPS_FORMAT_FIGEXP M_FIG C_FIG