Ecological and biological studies on some spiders from some habitats in Egypt and Sudan / Ahmed Ramadan Ali Ahmed ; Supervised Wafai Zaki Azer Mikhail , Mohammed Hassan Elerkssosy

Thesis (Ph.D.) - Cairo University - Institute of African Research and Studies - Department of Natural Resources

Spiders were the subject of these studies, which were divided into three steps 1-Ecological studies: This study conducted on Wheat crop, in Aswan Governorate at four regions (Edfo, Kom Ombo, Daraw and Naser El Noba), during the two seasons 2016 and 2017. The survey resulted 47 species followed 41 genera, listed under 18 families. In the first season 2016 existed 42 species followed 38 genera listed under 15 families. While in the other season existed 45 species followed 40 genera listed under 17 families. 2-Biological studies: The parents{u2019} generation of the spider Theridion spinitars reared on two preys (the first and second stages fed on Tetranychus urticae while the rest of the stages to the death reared on the Cuban laurel thrips Gynaikothrips ficorum. The biological studied continued on the first generation to studying the feeding capacity of the species Theridion spinitarse on the cotton leaf worm Spodoptera littoralis. Thus the first generation reared also on two preys (the first and second stages fed on Tetranychus urticae while the rest of the stages to the death reared on Spodoptera littoralis. The rearing conducted in temperature and relative humidity of the room. The life span recorded about 112.35 days for males while it was about133.26 days for females.. 3-Biological control study: The spiders were released in the greenhouse on the select cotton to control both of the two-spotted spider mites T.urtica and the cotton leaf-worm S. Littoralis. Spiders succeeded in control of the pest Spodoptera Littoralis. Where the population densities of the pest decreased to zero in the third week after the release Therefore the reduction percentage recorded 100%., while the averages of the population densities were decreased significantly at level (10) in the rest weeks. However the reduction percentages ranged between (35.88% - 84.16%) at level (5), while ranged (71.89% - 100%) at level (10)

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