Control of the two spotted spider mite, Tetranychus cucurbitacearum (Sayed) using conventional acaricides resulted in many problems. Thus, this study aimed to evaluate the effect of silica nano-particles (SiNPs) as a new approach to control spider mite on soybean plants. Three concentrations of SiNPs (250, 350 and 450 ppm) were sprayed on two soybean varieties, Giza 35 and Giza 111 during 2014 season. The reduction percentage in the population of the mite was recorded under field conditions. The obtained results indicated that the mean reduction percentage in mite population appeared a concentration response. The concentration of 450 ppm of SiNPs induced the highest reduction of mite on both soybean varieties Giza 111 and Giza 35, with values of 78.91% and 62.34%, respectively, followed by concentrations of 250 (71.24% and 38%) and 350 ppm (62.16% and 41.92%),respectively throughout the experimental period. The motile stages of mite T. cucurbitacearum on soybean variety Giza 111 was more susceptible to SiNPs than variety Giza 35. On the other hand, the highest values of seed yield/fed were recorded for the two varieties grown at 450 ppm in contrast with the control and250 ppm which produced lower seed yield/fed. High differences in SDS-Polyacrylamide gel electrophoresis protein profiles were found between two soybean genotypes treated with different concentrations of SiNPs. Increasing SiNPs concentration, increased changes in protein profile in both soybean genotypes. Six RAPD primers revealed low to moderate polymorphism and genetic variations among the different concentrations of SiNPs and between both soybean genotypes. The changes in DNA profiles included variation in band intensity, presence or absence of certain DNA bands and even appearance of new bands. Genomic template stability test was performed for the qualitative measurement of changes in randomly amplified polymorphic DNA profiles. This study concluded that DNA stability was affected by SiNPs concentrations of 350 and 450 ppm for both soybean varieties as identified by RAPD markers.

Control of the two spotted spider mite, Tetranychus urticae(Koch) using the conventional acaricides resulted in many problems . So, this study was carried out to evaluate the toxicity of certain alternative pesticides against this pest ,T. urticae as well as some biological aspects under laboratory conditions using two aromatic oils (Basil and Carnation) .one natural oil (Nat-1) and one conventional acaricide (Helbstar). The results indicated that Helbstar was the highest toxic compound to adult females of T. urticae followed by Nat-1 with Lc50 values of 1686.5 and 2861.5 ppm, respectively while Basil was the least toxic one with Lc50 value of 5990.4 ppm . The population showed more homogeneity in its response to the aromatic oils (Basil and carnation). Also, the results showed that the Helbstar caused the highest reduction in egg deposition with a mean number of 1.0 egg / day followed by Nat-1 with a mean number of 4.45 eggs / day , while Carnation was the lowest one with a mean number of 11.85 egg / day. The egg hatchability decreased with the increase of egg age at treatment by Basil , while in treating 1,2 and 3 day old eggs , the highest reduction in hatchability was found for Nat-1 , Helbstar and Carnation, with 100% reduction in hatchability at the three ages .Thus, the obtained results are of a great importance as they are taken into account in planning programs of integrated pest management.

Extensive use of conventional pesticides and acaricides to control of the two spotted spider mite, Tetranychus urticae Koch caused undesirable side effects on environment, humans and animals so, it was necessary to look for alternative control methods including the use of aromatic oils and natural oils, as botanical acaricides . The present study was carried out to assessment bio-efficiency of some aromatic oils and other compounds on some biological aspects of T. urticae in laboratory at (25±2) ºC, and (65±5) %R.H. to finding safe a mean to human, environment , and animals as alternative to synthetic miticides used in the control this mite. Results indicated that Helbstar was the highest toxic compound to adult females of T. urticae followed byNat-1 with Lc50 values of 1686.5 and 2861.5 ppm, respectively while Basil was the least toxic one with Lc50 value of 5990.4 ppm . The population showed more homogeneity in its response to the aromatic oils (Basil and carnation). As a result to significant differences between different oils it was found that Carnation oil and natural oil (Nat-1) can be recommend in controlling mite through incubation stage of T. urticae . Also Carnation oil can be recommend in controlling active proto-nymph, total immature and life cycle stages of T. urticea . All oils were not preferred in controlling adult females of mite through pre-oviposition, oviposition, post-oviposition and longevity stages . The obtained results were important so they are taken in the consideration when planning programs of integrated pest management.

Field experiments were carried out at Sakha Agric. Res. Station Farm, Kafr El-Sheikh to evaluate certain kidney bean varieties (Pronco, French bean and Polesta) and two breeding lines( Fl hybrid and R1655 ) of bean, Phaseolus vulgaris L for their relative susceptibility to the spider mite, Tetranychus cucurbitacearum (Sayed) and the white fly, Bemisia tabaci (Genn.) on three varieties. during two successive seasons, 2008 and 2009 .Obtained data showed that T. cucurbitacearum recorded the highest numbers during the third week of July in the first season , while B. tabaci appeared its maximum in the fourth week of June. Meanwhile, in the second season the two pests recorded the highest number in the fourth week of July. The numbers of T. cucurbitacearum were higher than B. tabaci during the two study seasons. The population density of T. cucurbitacearum was higher in the first season than in the second one, while B. tabaci showed the reverse.Based on the mean number of the two study seasons, variety Polesta harbored significantly the highest population of T. cucurbitacearum followed by French bean and the breeding line Fl hybrid ,while R1655 was the lowest infested. The highest infestation with B. tabaci occurred on French bean while, Pronco and R1655 were the least infested.Regarding to the susceptibility degree to the two pests, varieties Polesta, French bean and breeding line Fl hyprid appeared susceptible. The variety Pronco appeared as low resistant and breeding line R1655 appeared as moderate resistant.Thus, the gained results should be taken into account in planning programs of integrated pest management in the bean fields.

Natural abundance of the ectoparasitoid Diglyphus isaea Walker was studied in four tomato greenhouses at Sakha, Mehalla Al-Kobra, and Metobus. The parasitoid showed low populations in March, then developed good populations that kept the populations of the serpentine leafminer, Liriomyza trifolii at low densities till the end of the season in all studied greenhouses.D. isaea recorded two peaks of abundance in three of the greenhouses, the highest peak recorded 21, 36, 28 and 31 individuals/ 50infested leaflets in greenhouses 1, 2, 3 and 4, respectively . The highest average numbers occurred in April in all greenhouses recording 18 ± 2.9, 24.3 ± 8.3, 23.0 ± 5.2 and 26.0 ± 5.2 individuals/ 50infested leaflets in greenhouses 1,2,3 and 4 ,respectively. On the other hand, the percentage of parasitism ranged between 17.8 ± 0.9 and 47.3 ± 1.3% recording its highest numbers in May in greenhouse 1 (43.3 ± 5.3%), and in April in greenhouses,2,3 and 4 recording 46.4 ± 5.1 , 43.6 ± 2.3 and 47.3 ±1.3% , respectively. The percentage of killed larvae according to host-feeding recorded its highest monthly average numbers in May in greenhouses 1, 2 and 3 (43.5 ± 5.3 , 29.0 ± 9.2 and 24.0 ± 7.3% respectively) and in June in greenhouse 4 recording 30.6 ± 6.4% .