EFFECT OF GAMMA IRRADIATION ON CERTAIN BIOLOGICAL ASPECTS OF THE BLACK CUTWORM, Agrotis ipsilon ( HUFN.)

The biological effects of low doses of gamma radiation on full grown male and female pupae of the black cut worm, Agrotis ipsilon (Hufn.)  concerning their (P₁) generation and its influence on their first (F₁) generation were studied. 
       The results confirmed that, the average number of eggs of the parental generation (P₁ ) was significantly reduced when both sexes were exposed to 100 and 150 Gy. The highest reduction was clearly observed in P₁ female. However, on exposing both sexes to 50 Gy, results showed that, the average number of eggs was not significantly affected in case of  full grown male pupae, while it was significantly reduced in case of irradiated full grown female pupae in comparison to the untreated control.
               Results also showed that the percentage of egg hatch of P₁ generation was gradually reduced by increasing the irradiation dose in both the full grown male and female pupae. This reduction was significant at 50, 100 and 150 Gy in case of P₁ female generation and at 100 and 150 Gy in case of P₁ male generation in comparison to the untreated control as the percentage of egg hatch was not significantly reduced at 50 Gy for P₁ male. The results on mating ability through the P₁ generation showed that irradiation of males and females by low doses of gamma rays at 50 and 100 Gy did not clearly affect the percentage of mating at any of the tested doses.
              While the percentage of mating clearly reduced at 150 Gy in both sexes. Results also showed that, the average number of spermatophores per mated female was decreased by increasing the dose to parental males.
          The Percentage of F₁ progeny survived to adult stage was reduced at 50 Gy and the reduction increased by increasing the dose of irradiation. the average larval duration seemed to be about the control in the progeny of the 50 Gy, while the average larval duration increased at 100 and 150 Gy compared to their control treatment. The average pupal duration seemed to be about the  control in the progeny of the 50 Gy, while  the average pupal duration at 100 and 150 Gy was clearly affected compared to the control treatment. The percentage of pupation seemed to be about normal at 50 Gy, while it was reduced at 100 and 150 Gy, respectively. The percentage of adult emergence decreased with increased irradiation dose. The sex ratio among the progeny of irradiated males seemed to be skewed some what to male side especially at 100 and 150Gy