An attempt was made to find out the effect of heavy metal zinc (25ppm median lethal concentration) on fat body, testis, seminal vesicle and MAGR’s of Odontopus varicornis. Zinc is the fourth most widely used metal in the world and also one of the ubiquitous elements in the world. Heavy metal zinc causes the destruction of the beneficial species directly or indirectly through breaking the biological food chain. Enzymes are the attractive indicators because they are more easily quantified than the other indicators. The metabolic pathway mainly depending on enzyme- activities may be affected due to the destruction under the stress, reflecting the changes of enzyme activities. Investigators were made on the TCA enzymes, SDH, GDH and MDH. The heavy metal, zinc brought drastic changes in the antioxidant enzymes to reduce the detoxification mechanism which intern causes the mortality of the insects. In conclusion, the heavy metal zinc decreased the enzymatic antioxidant levels drastically from the selected tissues of Odontopus varicornis.
