الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 197 |  |  |
| | | from | 197 | | |
Abstract
The present work deals with the effects of gamma irradiation on Agrotis ipsilon (Hufn.), to induce inherited sterility. Special attention was given to study reproductive biology and inherited sterility throughout two successive generations, in hope of promoting the sterile insect method for the pest. br This work comprised the study of effects of six low doses (75, 100, 125,150, 175 and 200Gy) of gamma radiation as well as two species of EPNs (Steinernema Carpocapsae All and Steinernema riobrivae ). Special stress was given to compare the responses of F1 progeny of partially sterile male parents to S. Carpocapsae with those of F1progeny of nonirradiated male parents. br The obtained results can be summerized as follows: br 1. Effect of Gamma Irradiation on Reprodutivity: br When full grown male pupae were irradiated with the doses of, 75 100, 125,150, 175 and 200Gy and crossed with untreated females br 1. Both the percentage mated males with untreated females and copulation duration to format spermatophores directly in the female bursa copulatrix were not affect with the doses used. br 2. The percent of mated female with spermatophores and percent of mated female with sperm in spermatheca were not evidently different -#102;-#114;-#111;-#109; the control except on the high doses 175 -200 Gy. br 3. Lower percentages of males were observed in copulation with untreated virgin females in the second and third mating than the first mating . br 4. Number of eggs /female deposited by females mated to irradiated males and egg hatch were significantly reduced as a result of irradiation male treatment through three females. br 5. Also Number of eggs /female deposited by females mated to irradiated males and egg hatch were significantly less in second female and third female compared to the first . br 6. Significant differences in mating aspects and reproductive parameters within three sequential mated females, however significant differences was not be observed within the doses. br 7. Slight reduction in the average number of matings of the treated males was observed due to radiation doses. br 8. The irradiated males with tested doses as well as untreated control could be responsing to calling females and start copulation at the same period of the scotophase. br 9. The mating competitiveness calculated -#102;-#114;-#111;-#109; the direct observation in A. ipsilon revealed that males emerged -#102;-#114;-#111;-#109; pupae irradiated at 75 to 125 Gy are equally capable of mating as control. While, the competitive value decreased with the dose increased after that. br 2.Effect of dose 125 Gy used to irradiated males- females full grown pupae on biological aspects of P1and F1generations br A. Effect of dose 125 Gy used to irradiated female br 1. Radiation exposure of 125 Gy had no effect on percentages of treated females mating or times in copulation with untreated males. br 2. Percentages of females mating over all radiation doses decreased with new virgin males provided during the second and third mating period the first male more than the first male. br 3. The fecundity of the black cutworm, female was not significantly affect when full grown female pupae were exposed 125 Gy while, the percentage of egg hatch was significantly reduced br 4. The average numbers of sequential male matings not affect br 5. The treated females with 125Gy had no effect on calling behavior and attracting to wild males. br B- Effect of dose 125 Gy used to irradiated male on biological br aspects of P1and F1generation br 1. The percent emergence not affect, the percentage of malformed adults increased in treated insect compared to untreated insect and adult longevity slightly reduced by irradiating. In general, BCW female slightly affected by irradiating more than male br 2. The mating competitiveness of the black cutworm parental irradiated males with low doses of 125 Gy were fully competitive against untreated males in mating with normal females in all tested ratios. br 3. The average developmental period -#102;-#114;-#111;-#109; egg hatch to adult emergence was obviously increased in the progeny of two filial generations. br 4. The percentage of pupation was not affected among in F1 and F2 progeny, the percentage of adult emergence was slightly reduced among the first filial generation descendent of parental irradiated males, however this reduction was clear in F2 progeny. br 5. The growth index showed a decrease as a consequence of irradiation of male parents in F1and F2 generations. br 6. The sex ratio, among the progeny descend of P1 generation, and the progeny descend of F1 generation did not differ -#102;-#114;-#111;-#109; the ratio observed in the control treatment. br 7. The percentage of mating success was not affected among in P1 generation, F1 and F2 progeny, the percentage of mating frequency was slightly reduced among the F1 and F2 progeny. br 8. The number of deposited eggs per mated female and the egg hatchability percentage P1, F1 and F2 generations were significantly reduced as a result of irradiated parent with 125 Gy br 9. The present results indicate that F1 progeny were far more affected than their irradiated P1male parents, and the deleterious effects on F2 pairs were not as severe as on F1 pairs, but still greater than the irradiated parents br 10. The production of female adults resulting -#102;-#114;-#111;-#109; P1 irradiated males and F1 generation decreased as result of irradiation treatment, and the greatest reduction in F2 progeny. br 11. Although the number of eupyrene sperm bundles descended to duplex was not affect during the first dark-light cycle of sperm descendence, the volume of testes significantly reduced specially in P1male parents. br 12. Accumulation of eupyrene sperm bundles of unmated F1 males was significantly reduced. br 3. Effect of EPNs on Agrotis ipsilon. br 1. The used species Steinernema Carpocapsae (All) and Steinernema riobrivae were effective against tested pest. br 2. There were significant increases in percent mortality, significant decreases in both percent adult emergence and percent surviving -#102;-#114;-#111;-#109; infested larva to adulthood as a result of increasing of concentrations br 3. R2 value showed strong correlation between mortality values and concentrations br 4. The LT50 values showing that the S. carpocapsae was faster to be infested A. ipsilon. than S. riobriva br 5. Tabulated data revealed collinear relationship between the exposure periods to 100 IJs/larvae of S. carpocapsae and the total morality percent and the percentage of adult malformation. br 6. On the contrary, treating larvae with S. carpocapsae at concentration 100 IJs /larvae showed significant decreasing to the percentage of pupation and the percentage of adult emergence. br 7. The reduction in mating ability percentage and percentage of mated females received sperm increased almost gradually with the increase in exposure period. The highest effect occurred when treated males were descended -#102;-#114;-#111;-#109; treating larvae with S. carpocapsae at concentration 100 IJs /larvae . br 8. It was observed that the number of deposited eggs per mated female and the eggs hatchability percentages were significantly reduced at the most mating combinations through the both tested adult lines . br 9. It could be mentioned that the employed application methods were effective against and had obvious effect on the percent of cumulative mortality and percent of reduction in progeny of A.ipsilon . br 4. Combined effect gamma irradiation and (EPNs) S. carpocapsae on Agrotis ipsilon . br 1. F1 progeny of A .ipsilon irradiated parents with 125 Gy were more susceptible S. carpocapsae than those of nonirradiated parents at a low concentration. br 2. But F1 progeny of both parents had similar susceptibility at higher concentrations S. carpocapsae . br 3. In this study, the combination of tested treatments at all concentrations resulted in additive effect. br 4. Data clear that no significant influence of induced sterility of the host (F1 sterile insects) on both of the parasitisation efficacy of EPNs, and on the mortality induction process. The onset of morbidity and mortality induced by normal IJs (i.e., IJs derived -#102;-#114;-#111;-#109; untreated host) was not different in F1sterile hosts and un-irradiated controls. br 5. The incubation time taken by IJs on F1 sterile hosts was significantly prolonged, in F1 hosts derived -#102;-#114;-#111;-#109; 125 Gy treated male parent (P-lt; 0.05). br 6. The IJs harvest was found significantly reduced on F1 hosts. The harvest period was also slightly affected by the radiation dose applied to the host in the previous generation. br 7. Regarding to the infective performance of IJs cultured in parasitized F1 sterile A .ipsilon., no evident interaction was noticed between the irradiation background of IJ’s parent host (as cultured) and the nature of the current host (as infective) on parasitisation behavior of EPNs. br 8. Incubation time taken by IJs that had been cultured F1sterile hosts was significantly affected. It means the incubation time taken by IJs -#102;-#114;-#111;-#109; radio-sterilized hosts was prolonged on normal br 9.The reduction in harvest potential of IJs depended upon the gamma dose administered to male parent of F1 insects (as hosts)as well as F1 hosts.