No abstract

a b s t r a c tThree substerilizing doses 50, 100 and 150 Gy of gamma radiation were tested against full e grown male and female pupae or against full-grown male or female pupae of Agrotis ipsilon.The results showed that fecundity of irradiated females crossed with irradiated males was decreased by increasing irradiation dose. The decrease in egg e hatchability % and increase in sterility % induced by gamma radiation were found to be positively correlated with the dose level. The parentage of larval and pupal mortality increased significantly (p 0.05) with the increase of used doses. In addition, larval and pupal durations were found to be significantly prolonged as a result of gamma-irradiation treatment. In general, the results obtained indicated that the biological action of gamma irradiation against A. ipsilon larvae was more remarkable when both crossed females and males were irradiated followed by irradiated females crossed with non-irradiated males.

Four native isolates of entomopathogenic fungi (EPF) Beauveria bassiana (B1and B2), Metarhizium anisopliae (M1 and M2 ) were isolated and evaluated against wheat aphid, Schizaphis graminum (Rondani). Three concentrations of spores suspension from each of the four fungal isolates (1×10 6 , 1×10 7 and 1×10 8 conidia) were used against adult aphid (one day old). The results showed that (B1) was the most effective according to LC50. Whereas, when testing the toxicity of crude metabolites of fungal isolates in four concentrations for each isolate, it was found that the highest effective toxin was (M1) followed by (B1), (M2) and (B2). Scanning electron microscope photographs (SEM) showed the mode of action of entomopathogenic fungi and its ability to colonize and how it infects aphid.

No abstract