Fate of gamma radiation exposure on radio-tolerant insect Chironomus ramosus

Following Chernobyl nuclear plant explosion in 1986, various research groups investigated flora and fauna inhabiting the radioactive fallout zones. Chironomid midges attracted the attention of radiobiologists as they showed remarkable ability to survive in highly contaminated areas. Our previously published work also discussed tolerance of Indian tropical species of midge Chironomus ramosus to high doses of gamma radiation stress. Present work focuses on the fact that differential dose rates of gamma irradiation led to differences in survival pattern of Chironomus larva. Acute exposure of larvae with a dose rate of 55.6 Gy/min (HDR) showed LD₂₀ of 1700 Gy while larvae subjected to chronic exposure with a dose rate of 5.5 Gy/min (LDR) led to LD₂₀ of 2200 Gy. Enhanced larval lethality with increment in dose rate motivated us to investigate the mode and mechanistic basis of lethality