The goal of this work was to investigate the effect of gamma irradiated entomopathogenic nematode EPN; Steinernema scapterisci on third and fourth larval instars of Culex pipiens under laboratory conditions and its effect on the elemental composition of the treated larvae. Results showed that normal and irradiated tested nematodes differed in their efficacies against third and fourth larval instars. The mortality rates increased with increasing the nematode concentration and the period after treatment, in most cases the mortality in fourth instar larvae was more than in third instar larvae under the same treatments, and the percentage of mortality in irradiated nematodes was more than that in unirradiated ones. Studying the elemental composition showed that phosphorus (P) was the highest concentration in untreated larvae or those treated with normal S. scapterisci, while calcium (Ca) was the highest concentration in gamma irradiated S. scapterisci. The lowest concentration in untreated larvae was zinc (Zn), while copper (Cu) was the lowest concentration in unirradiated and 2 Gy gamma irradiated S. scapterisci. In conclusion, the gamma irradiation of S. scapterisci enhanced its efficacy against C. pipiens, therefore it could serve as safe control method for C. pipiens.

Nowadays, the sterile insect technique is broadly used as a pest control measure. Therefore, the present study was conducted to investigate the alteration occurred in testes and DNA pattern as an effect of inherited sterility. Full grown pupae of the wax moth, Galleria mellonella were irradiated with 80 and 160 Gy of γ irradiation. The size of the testes was decreased by increasing of γ irradiation dose. Also, the size of the testes was decreased in F 1 males comparing with the size of the testes of both the parents and the untreated control. The effects of γ rays on the DNA patterns of adult male parents and F 1 males showed alterations among the controls, the treated parents and F 1 individuals. Exposure to radiation caused very frequently the appearance of some extra bands and the deficiency of others in the arbitrary random amplified polymorphic DNA-polymerase chain reaction amplification patterns of the irradiated insects.

Nowadays, radiation technique is widely used food preservation and pest control. Therefore, the present study was conducted to investigate the biochemical alterations in Tribolium confusum adults irradiated with the sterilizing dose (60 Gy) or fed on flour irradiated with the sterilizing dose for flour (3Kg). The results indicated a significant decrease in the nutritional contents (protein, lipids, and carbohydrates) in the studied samples when compared to control. The digestive enzymes (protease, lipase, and amylase) of T. confusum adults were estimated and they revealed that protease and amylase activities showed a significant decline in the gamma-irradiated adults, and a significant elevation in adults feed on irradiated flour. Moreover, lipase activity was non-significantly changed in the studied samples when compared to the control. In conclusion, it is noticeable that gamma irradiation of T. confusum more effective than flour irradiation but we can use food irradiation technique in combination with other control tools for controlling T. confusum.

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