Field experiments were carried out in Egypt to investigate the infestation rates of cotton whitefly Bemisia tabaci on five cultivars of cucumbers Cucumis sativus during two consecutive late summer seasons from 11 August to 28 October 2015 and 2016. The susceptibilities of the cultivars to infestation by this pest were examined. The five cultivars – Hayl, Nems, Beit Alpha Zena, Bahi and Wafier – were cultivated on a private farm in Mansheyet Saqqara village, Giza. The results showed that whitefly infestation peaks were high in September and October, but low in November in both seasons. The population densities of Bemisia tabaci eggs, nymphs and adults on all the cultivars were slightly higher in 2015 than in 2016. Numbers of B. tabaci eggs, nymphs and adults rose with increasing the temperatures in both seasons, and mean numbers of nymphs and adults also increased with decreasing RH% on all the cultivars. The combination of temperature and humidity was an important regulatory factor affecting B. tabaci development. The results of this study showed that high infestation peaks of B. tabaci occurred in September and October of both seasons. The present results were used to classify the degrees of susceptibility of these cucumber cultivars to B. tabaci infestation as susceptible (S), low resistant (LR) and moderately resistant (MR). It is important that these degrees of susceptibility be referred to the degree of resistance of each cultivar to insect infestation.

Effects of different verities of potato tubers as a food Cara, Spunta and Rosetta on food ability, developing, fecundity and life table parameters of Phthorimaea operculella were studied under laboratory conditions. Egg incubation period was longest in time when Ph. operculella reared as larvae on Rosetta variety and spent 5.5 day. The natural mortality data for larvae reared on Cara variety were 23.14, 19.67 and 2.4%, respectively. Pupal duration which reared on the potato varieties Cara, Spunta and Rosetta were 9.22, 10.68 and 12.23 days, respectively. Duration of the generation was 40.90 and 35.9 days, on Cara and Spunta varieties, respectively. The obtained results indicate that potato variety Cara demonstrated the highest net reproductive rate (37.7 eggs/female) followed by Spunta variety (22.7 eggs/female) and Rosetta variety (16 eggs/female)

The of effect different stages of predator Coranus africana EL-Sebaey was evaluated in suppression for different populations of the white fly Bemisia tabaci Genn. In tomato field at Qalubia and Bani-Swif Governerates during two successive years 2007 & 2008, different stages of the predator C. africana were released by one predator/plant against B. tabaci infestation. Reduction percentage of B. tabaci infestation differed according to the release of predator in each treatment. In case of release of the adult stage, the reduction in the second week of release was 93.4% & 100%) for adult and immature stage respectively at Qalubia during the first year. On the other hand this reduction was (94.8% & 97.1%) during the second year. However the percentage reduction at Bani-Swif was (97.4% & 92.7%) and (99.2% & 91.2%) during two years respectively. The basic yield parameters expressed as weight of fruit and number of fruits/plant during the two years of the investigation at Qalubia and Bani-Swif in the crop.