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Acute contamination with esfenvalerate and food limitation: Chronic effects on the mayfly, Cloeon dipterum
Author(s) -
Beketov Mikhail A.,
Liess Matthias
Publication year - 2005
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/04-256r1.1
Subject(s) - mayfly , microcosm , toxicology , intraspecific competition , biology , contamination , ecotoxicology , population , chronic toxicity , pesticide , larva , toxicity , zoology , ecology , environmental health , medicine
Results of environmental risk assessments based merely on toxic effects of contaminants at the individual level, without consideration of population‐level effects, may be questionable. The aim of the present study was to investigate how limited food resources, resulting in intraspecific competition, could interact with the chronic effect of short‐term contamination with the insecticide esfenvalerate. Larvae of the mayfly, Cloeon dipterum , were exposed to esfenvalerate (0.001–100 μg/L) for 1 h and then transferred to indoor microcosms containing insecticide‐free water, where they were maintained at various food levels until emergence. The results showed that short‐term exposure to 10 or 100 μg/L resulted in acute mortality. Chronic effects on survival occurred at concentrations up to three orders of magnitude lower than that causing the acute effect (0.01 μg/L). Food limitation increased effects on organisms during medium‐term observation (8–15 d), but assessment of long‐term survival rates suggested that the chronic effects of low insecticide concentrations could be compensated for, at least regarding some endpoints. The authors assume that in limited‐food conditions, lethal and sublethal effects reduced competition between individuals, resulting in significantly increased final survival.