الفهرس 
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Abstract
Faba bean, Vicia faba L. and cowpea, Vigna unguicutata (L.) Walp. are of the most important legume crops all over the world. They are attacked by several insects in the field, among of them are aphid insects. Therefore, the aim of this work was to survey and seasonal abundance of aphid species and the common associated predators on the two crops in relation to the prevailing weather factors in addition to susceptibility of some varieties to aphid infestation at Sakha Agric. Res. Station Farm during season of 2016/17 and 2017/18 for faba bean and of 2017 and 2018 for cowpea. Also, this work involved some biological aspects of cowpea aphid, Aphis craccivora Koch. reared on faba bean plants under laboratory conditions.
The obtained results showed four aphid species: Aphis craccivora Koch., Aphis gossypii (Glov.), Myzus persicae (Sulz.) and Acyrthosiphon pisum (Harris) on faba bean, while only the first and second species were found on cowpea. A. craccivora was the most dominant species, while A. gossypii was the least on the two crops. Aphid species recorded two and one peak of abundance on faba bean in the first season and the second one, respectively, while it recorded one peak on cowpea in the two seasons. The observed predatory insects were chrysperla carnea (Steph.), Scymnus spp., Coccinella undecimpunctata L., Paederus alfierii Koch. and Orius sp. in addition to unidentified true spiders on the two crops with exception of P. alfierii that did not found on cowpea. Ch.carnea was the most dominant predators, while P. alfierii and C. undecimpunctata were the least ones on faba bean and cowpea, respectively.. In season of 2016/17, the temperature, relative humidity, wind speed and rainfall as well as the predators had an insignificant effect on aphid species on faba bean except wind speed effect on A. gossypii which it was significant. During season of 2017/18, only relative humidity induced positive and significant effect on aphid species. On cowpea, only the true spiders had a positive and significant effect on the aphid species in the second season. According to the susceptibility degree to aphids, faba bean varieties Misr1 and Giza 843 appeared as susceptible, while Sakha 3,4 and Giza 40 showed low resistance. Cowpea varieties, Kream 7 and Kafr El-Sheikh-1 were susceptible, Kaha 1 and Dokki 331 appeared medium resistance, while Tiba was low resistant. The nymphal duration of A. craccivora was 8.04+0.62 and 8.49+ 0.63 days for the first and second generation, respectively. Also, adult longevity was 10.59 + 1.37 and 11.94 + 1.89 days, while life span was 18.62 + 1.96 and 20.43 + 2.52 days for the two successive generations, respectively. The generation time lasted 8.71+ 0.38 and 9.35 + 0.43 days for the two generations.
Thus, the obtained results are very an important and useful in the development of an integrated management program for aphid insects in faba bean and cowpea fields to minimize the bad effects of insecticides for control these insects.