Population studies on nine cicadellid species were carried out throughout 1974 at Giza, Egypt, using a modified light trap and sweeping net. These species, arranged descendingly according to their abundance in light trap catches were : Cicadulina bipunctella zeae CHINA, Exitianus taeniaticeps (KIRSCHB.), Recilia schmidtgeni WAGNER, Cicadulina chinai GHAURI, Nephotettix modulotus MEL., Neolimnus aegy tiacus (MATS.), Balclutha rufofaasciata MERINO, Macrosteles sexnotatus (FALLEN), and Orosius albicinctus %IS,. Light trap catches of the majority of these species were relatively abundant only during warm-humid months: August till October. These species were found on a large number of host plants; the average number ofeach species/100 strokes on each host was determined. Sex ratios in light trap and sweeping net samples of most species are given.

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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

Maize Yellow Stripe Virus (MYSV) is a leafhopper-borne Tenuivirus that has induced some epidemics on maize plants earlier in Egypt. Field samples from maize plantations were taken during the summer and Nily growing seasons of 2004 and 2005 to estimate the occurrence of MYSV on maize in ten governorates of Middle and Lower Egypt. Disease severity and percentage of MYSV incidence were recorded. Visual examination of MYSV symptoms, serodiagnosis using DAC-ELISA, and sometimes molecular tools (IC/RT-PCR and hybridization) were used to detect the disease occurrence in maize leaf samples. Generally, MYSV occurrence was higher in Middle than in Lower Egypt. Also, it was higher in Nily than in summer plantations. However, MYSV incidence in the summer season of 2004 was higher than in Nily season of the same year. The epidemiology and transmission of this virus by Cicadulina chinai is discussed.