Metal kinetics and respiration rates in F1 generation of carabid beetles (Pterostichus oblongopunctatus F.) originating from metal-contaminated and reference areas.

We investigated resistance to metals in carabid beetles inhabiting metal-polluted and reference areas. Chronic multigeneration exposure to toxic metal concentrations may potentially result in adaptation through decreased metal uptake rate and/or increased excretion rate. The cost of resistance to pollution could be associated with increased metabolic rate. To test these predictions, laboratory cultured F(1)-generation beetles originating from metal-polluted and reference sites were exposed to food contaminated with zinc and/or cadmium for 10 weeks. After that, uncontaminated food was offered to the animals for another 3 weeks. During the experiment, internal concentrations of Cd and Zn were measured as were respiration rates of the animals. The results obtained show no significant differences in metal accumulation and excretion patterns or respiration rates between the populations. This may suggest that adaptation has not occurred in the beetles chronically exposed to toxic metal concentrations. The possible explanations for the lack of differences between the populations are discussed.