Abstract: In order to explore the effects of heavy metals on transfer, biomagnification and developmental duration in spiders, the changes of cadmium content in various instars of Pirata subpiraticus fed with Drosophila melanogaster flies reared on artificial diets were detected by atomic absorptions spectrometry and indirect effects of cadmium on its developmental duration were measured. The results showed that excessive cadmium in food could be transferred by food chain and accumulated in P. subpiraticus and the accumulation level increased with instar duration extended, which was significantly positively related with the number of fruit flies ingested and the cadmium content in food, respectively. It was estimated that 65.4% of the Cd²⁺ was assimilated by the spiders and the biomagnification factor was approximately 1.8. Cd²⁺ content in P. subpiraticus had no significant change in the observed 4 weeks of feeding with uncontaminated flies. Cadmium in food significantly led to lengthening of developmental duration and reducing of starvation tolerance in P. subpiraticus. The results might provide adequate basic theory on Cd²⁺ transmission, biomagnification and physiological tolerance along the soil-insects-predators.

Key words: Pirata subpiraticus, food chain, heavy metal, cadmium, accumulation； elimination, biomagnification, developmental duration