Potential Methods for Identification the Gamma Irradiated from Unirradiated Larvae of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

Abstract

To verify the irradiated from unirradated Helicoverpa armigera larvae through the two methods, the 1^st , 2^nd , 3^rd and 4^th instar larvae were irradiated with gamma radiation at 0, 75 and 150 Gy and observed in the late 5th instar. Irradiated at 75 Gy, the total haemocyte counts (THCs) of
the irradiated 1^st , 2^nd , 3^rd and 4^th were found to be 6207±178, 6990±215, 9014±244 and 9991±279 h/mm³ respectively while those irradiated at 150 Gy averaged 3939±156, 4988±157, 5704±203 and 5904±218 h/mm³ respectively. It was also revealed that phenoloxidase (PO) activities of the irradiated 1^st , 2^nd , 3^rd and 4^th larval stages were 2.6±0.7, 9.7±0.7, 16.6±2.6 and 23.7±2.6 units/mg protein respectively whereas those irradiated at 150 Gy averaged 0.8±0.1, 4.6±0.5 , 10.4±1.3 and 15.0±1.4 units/ mg protein respectively. The results of the effects of radiation on THC and PO activity
supported each other. The changes in such experiments on each instar at each dose were found to be significantly less than THC (12921±605          h/mm ³) and PO activity (31.6 units/mg protein) of the controls. In both doses, percent reduction of THC and PO activity also increased from the 4^th to 1^st instars.