الفهرس 
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Abstract
Survey of pests fauna associated with onion at both open field and store, were carried out at Experimental Research Station, in Kafr- Elshekh governorate during the two successive seasons [2013/14 and 2014/15]. Onion variety namely Giza 20 was direct seed in nursery bed on 15th November 2013 and 10th November 2014. Plants were transplanted, 5 th January 2014 and 6th January 2015. The main insect pests infesting onion plants during the two seasons were Thrips tabaci (47.05 and 48.11%), Aphis gossypii. (17.03and 19.61 %), Eumerus amoenus. (6.65and 4.05%), Empoasca lybica (7.46 and 7.03 %) and Liriomyza trifolii (3.16 and 3.99%) in 2013/14 and 2014/15, respectively. On the other hand, the main insect pests attacking onion plants with low occurrence were Nezara viridula (1.79 and 2.07%), Bemisia tabaci (7.13 and 6.61 %), Spodoptera littoralis (3.03 and 2.78%) and Cryptoblabes gnidiella (1.03 and 1.22%) during the two successive seasons, respectively. 2. Population abundance of the main insect pests:-2.1. The onion thrips T. tabaci :-The maximum number of Thrips tabaci nymphs by using direct count method was 843 and 812 individuals/40 plants in the second week of April 2014 and the first week of April 2015. The average number of T. tabaci nymphs were 713.52 and 628.50 individuals /40 plants during the two seasons 2013/14 and 2014/15, respectively.2.2.The onion aphid, A. gossypii:- The highest peak of A. gossypii nymphs were 392 and 357 nymphs /40 plants in the second week of April during 2014 and 2015, respectively. Moreover, the highest average of A. gossypii was recorded in April with an average number of 282.00 and 260.50 individuals/40 plants during 2013/14 and 2014/15, respectively. 2.3. The cotton leafhopper E. lybica: - The highest number of E. lybica was recorded in the Fourth week of April (122 and 122 individuals/40 plants) during 2013/14 and 2014/15, respectively. Moreover, the highest average numbers of E. lybica recorded in March in the first season and April in the second season and represented by91.41 and 77.52 individuals/40 plants, respectively. 2.4. The onion bulb fly E. amoenus :-The highest peak of E. amoenus was recorded in the second week of May 2014 during the first season and in the fourth week of April 2015 during the second season and represented by 144 and 102 individuals/40 plants, respectively. Moreover, the highest average numbers of E. amoenus recorded in May 2014 and April 2015 during the two seasons and represented by 114.67 and 51.52 individuals/40 plants, respectively. 3. Population abundance of the main predators: -The main predators which recorded on onion plants and associated with the insect pests’ infestation during the two successive seasons were 6 species. The presence of Paederus alferii ranked the first category by 40.87 and 38.20%, followed by Coccinella undecimpunctata (16.55 and 15.10%), Coccinella septempunctata. (14.64 and 14.65%), Oruis sp (11.31 and 12.07%). Otherwise, the least abundance of predators was recorded with Cydonia vicina niloitica (9.78and 11.01%) and chrysoperla carnea (6.83 and 9.65%) during two successive seasons, respectively.4. Population abundance the onion bulb fly E. amoenus in store:-The highest peak of E. amoenus abundance was recorded in the third week of September 2014 and 2015, respectively, during the two seasons were 286 and 254 individuals /100 bulbs. Moreover, the highest average numbers of E. amoenus recorded in August 2014 and 2015 during the two seasons of study and represented by 205 and 190 individuals /100 bulbs, respectively. 5. Susceptibility of three date’s onion planting to infestation by themain insect pests: - Onion seedlings were planted on three different agricultural dates (December, January and February) during the 2013/14 and 2014/15 study seasons to study the effect of different planting dates on the population density of the main insect pests attacking onion crop. The Thrips tabaci showed the highest number and percentage in the third planting date during the first and second season which represented by 7605 individuals (52.57%) and 7950 individuals (59.41%), respectively. The highest number and percentage of Aphis gossypii, Empoasca lybica and Bemisia tabaci the third planting date attractive during the two successive seasons. While, Delia alliria showed the highest number and percentage the first and second planting dates during the first and second season, during respectively. There were significant differences between planting dates in numbers of T. tabaci, A. gossypii, and E. lybica, whereas differences in numbers of D. alliria among planting dates were insignificant during the two study seasons.6. Susceptibility of three onion varieties to infestation by the main insect pests: where three main onion varieties (Giza 6, Giza 20 and Giza Red) were cultivated, during two seasons, to study the influence of different onion varieties on the population density of the most important insect pests. The highest populations of all investigated insects were recorded on variety Giza 6 followed by Giza 20 and Giza Red during the two-successive season. This study showed that the highest average numbers of Thrips tabaci. on Giza 6 were 316.6 ± 36.6 and 286.4± 34.1 nymphs during the first and second season, respectively.The highest average number of Aphis gossypii was also recorded on Giza 6 and represented by 1124 ± 22.4 and 1061±18.7 individuals, during the first and second season, respectively. The highest average numbers of Dalia allairia was also recorded on Giza 6 and represented by 37.7 ±7.6 and 41.3 ±8.5 during the first and second season, respectively. The onion varieties showed significant differences in their attraction to T. tabaci and A. gossypii, but not for D.allairia. For the Integrated Pest Management strategy for onion crop, Giza 6 has to be excluded from the approach of crop breeders and farmers due to its higher susceptibility for infestation.7. The impact of macro elements on the main insect pests of onion crop: - The macro-element N, P and K where tested in three different fertilization rates during the two successive seasons) on the population density and the average numbers of the most important insect pests that infested onion plants. The highest mean of the insect pests in the first rate followed by Second rate and third rate during the study seasons. The highest means of T. tabaci were 319.8 ±47.7, 265.1 ±35.2 and 250.7 ±30.1, respectively. Also, A. gossypii recorded the density by 124.9 ±20.3,100.2 ±17.1 and 86.6 ±15.9, respectively. The population of D. alliria were 21.8 ±4.5, 15.9 ±3.9 and 13.6 ±3.3 while, E. Lybica were recorded 36.8 ±4.4, 29.4 ±3.9 and 25.8 ±3.3. Moreover, B. tabaci were 14.9 ±2.6, 10.5 ±1.8 and 9.4 ±1.6., L. trifolii recorded 9.1 ±1.7, 7.5 ±1.3 and 5.0 ±1.2 during the two seasons of study.8. Influence of conventional and nonconventional insecticides against E. amoenus: - The conventional insecticide Malathion and Diazinon and non-conventional insecticides, Fibronil and Azadirachtin exhibited a high efficiency against the E. amoenus population with the highest percentages of reduction during the two successive seasons of the study. Moreover, fibronil and Azadirachtin recorded the highest reductions during the two-successive seasons against the E. amoenus after 15,30 ,45.00 and 60 days of treatments but the Azadirachtin more safety on human and animal farm.