Mulberry-silkworm food chain--a templet to assess heavy metal mobility in terrestrial ecosystems.

Assessment of the food chain mobility of heavy metals in the natural ecosystem receives more attention nowadays. In the present study, mulberry-silkworm food chain has been focused as a templet to assess the biomobility of heavy metals in soil-higher plant-insect hierarchy. Both in the case of Cd and Cu treatments, higher mobility was observed in the level-1 (soil-root) followed by level-3 (leaf-larva), level-4 (larvae-faecal) and level-2 (root-leaf). Consequently, roots accumulated more amounts of Cd and Cu, with a limited transport to the leaves. Among the two metals (Cd and Cu) tested, in the plant, the transfer potential of Cd exceeds that of Cu. Whereas in the case of leaf-larval transfer, Cu precedes over Cd. Accumulation of Cd and Cu in all the levels (1-4) tested showed a concentration dependent increase, except in the level 4 (larva-faecal) of Cd treatment where a declining trend was noticed.