Experiments were conducted to estimate the susceptibility of five tomato hybrids (Supper-gekal, F1Gs-12, Marwa, El-basha 1077 and Salymia 65010) to infestation with Tetranychus urticae Koch and its population fluctuation during the two successive seasons, summer 2013 and 2014, at Giza governorate. Supper-gekal and F1Gs-12 hybrids were the most highly significant susceptible to infestation. It recorded 31.16 (25.10%) & 24.61 (24.82%) and 28.10 (22.63%) & 22.09 (22.28%) moving mite stages / leaflet during 2013 and 2014 seasons, respectively, followed by moderate infestation observed on hybrids (El-basha 1077 and Marwa), being 25.20 (20.29%) & 19.80 (19.96%) for the former; 21.32 (17.17%) & 17.67 ( 17.82%) for the latter hybrid during the two seasons, respectively. The lowest infestation was observed on Salymia (65010) hybrid which recorded, 18.38 (14.81%) and 15.00 (15.13%) during the two successive seasons, respectively. Susceptibility of five tomato hybrids to infestation with T. urticae may be affected by plant leaf morphological and histological characteristics and its chemical contents. The number of leaf trichomes /cm 2 in upper and lower surfaces averaged (2606&8606), (3939&10557), (5788&9000), (7030&13870) and (10970&16818) for Suppergekal, F1Gs-12, El-basha 1077, Marwa and Salymia 65010, respectively, the less number of trichomes the more mite infestation. Also, the mean thickness of lower epidermis was 19.

Experiments were conducted to estimate the susceptibility of four watermelon cultivars (A swan, Daytona, Molokai and Giza-I) to infestation with Tetranychus urticae Koch and its population fluctuation during the two successive seasons. summer 2009 and early summer 20 I 0 at Qalubia Governorate. Aswan cultivar was the most highly susceptible recording average of 42.86 and 57.59 mite moving stages/leaf during the two successive seasons, respectively. followed by the moderately infested cultivars (Daytona) recording 28.10 and 39.75 mite individuals during the two seasons. respectively. The lowest infestation was recorded on Molokai and Giza-] cultivars, being 19.18 & 25.90 for the former and 18.10 & 25.94 for the latter cultivar during the two successive seasons, respectively. Susceptibility of watermelon cultivars to infestation with T urticae may be affected by plant leaf morphological structure and its chemical contents. The number of trichomes/cm 2 leaf averaged 647. 78, 744.44, 1111.11 and 1296.67 for Aswan, Daytona, Molokai and Giza-! respectively, the less number of trichomes the more mite infestation. Positive relationships occurred between mite infestation levels and total amino acids, free amino acids, nitrogen and total soluble sugars in watermelon cultivars, while negative relationship found with tannins and nearly shown with total phenolic compounds, total tlavonoids and total carotenes. Mite populations reached its peak during July and May in the first and second seasons, respectively, and infestation was lower in the first season than in the second, which might be due to early plantation.

The effect of the two predatory mite species Phytosiulus persimilis Athias-Henriot and Typhlodromips swirskii (AthiasHenriot), fungal entomopathogen, Beuvaria bassiana and the biochemical compound Abamectin (Vapcomic) were investigated against the two-spotted spider mite, Tetranychus urticae Koch on kidney bean (Paulista) and sugar snap pea (Snow wind) in a greenhouse at Behaira governorate during 2013 season. The average number of spider mite population was significantly different among the different treatments on Paulista (F 4,99= 39.025; P < 0.001; Table 1), and on Snow wind (F 4,99= 32.17; P < 0.001). The mean reduction percentage of spider mite populations on both plant varieties by P. persimilis was significantly the highest (95.2%), followed by treating with Vapcomic (90.0 %) and the fungus B. bassiana (84.8%); T. swirskii caused the least (71.9%). Thus, using P. persimilis to control the two spotted spider mite on the two plant varieties (Paulista and Snow wind) is recommended.

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