**18. Conclusion**

Environmental pollution by heavy metals is the global hazard due to increased industrialization, urbanization as well as anthropogenetic activities that show detrimental effect on ecosystem. The analysis has shown that heavy metals accumulation along the food chain increased the bioaccumulation factor with increase in trophic level. However, it is not directly transferred from plants but need insects for the transfer to higher trophic level. The biochemical, physiological and behavioral alteration in insects confirms the accumulation of heavy metals activity thus they act as good bioindicators of metal pollution to demonstrate the ecological impact of metals. Recent advances at biochemical and molecular levels are being done to determine the toxicity of heavy metals in insects. Steps should be taken to lessen the metal pollution and enhance the survival of insects with accumulation at the cost of additional energy.
