The effect of zinc (Zn2+) on cellular immune system of American cotton bollworm, Helicoverpa armigera Hübner (Lep.: Noctuidae)

Natural activities such as volcanic eruptions, erosion, springs water and human activities such as exploration, mining, agriculture and fossil fuels forms due accumulation of heavy metals in soil and implicit toxicity to plants, animals and humans. Among heavy metals, Zinc is considered as an essential element. The effect of median concentrations of zinc (25, 50 and 100 mg/ kg diet) was studied on cellular immune of American cotton bollworm. Our results demonstrated significant increase in total hemocytes count (THC) in 50 and 100 mg/kg concentrations of zinc compared to the control. In differential hemocytes count (DHC), prohemocytes were significantly reduced in 100 mg/ kg concentration of zinc but in 50 and 100 mg/ kg concentrations of zinc, oenocytoids increased significantly compared to the control. After latex bead injection, immune response (nodulation) significantly was enhanced in 100 mg/ kg concentration of zinc compared to the control. Understanding, the influence of environmental factors and stresses on immune responses can be effective solutions for pest control.