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Document Type |
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Thesis |
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Document Title |
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PREDOMINANT TRUE SPIDERS ( ARANEOMORPHAE ) COBWEBS,THEIR MAJOR INSECT PREYS IN THE ALFALFA AGROECOSYTEM العناكب الحقيقية السائدة وأشكال بيوتها المنسوجة وأهم فرائسها الحشرية في النظام البيئي الزراعي للبرسيم الحجازي |
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Subject |
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Biological |
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Document Language |
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Arabic |
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Abstract |
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The population dynamics of the major and predominant families of true spiders (Araneae) foliage and soil-dwellers in the alfalfa agroecosystem was determined. Twelve spider families have indicated an appreciable presence on the alfalfa foliage among them 3 predominant families including: Philodromidae, dady-long-legs Phalangidae (Pholcidae) and the jumping spiders Salticidae, in addition, the effect of alfalfa harvesting on the activity and density of these spiders were determined. The soil-dwelling spiders comprised seven families where 3 families were most dominant including Lycosidae, Gnaphosidae and Theridiidae. It has been observed that most of the foliage-dwelling spider species were able to spin their webs for hunting their preys, the shapes of these webs were determined. The major preys that fell in these webs including: Aphis trifolii, Aphis craccivora, Empoasca lybica, Empoasca disciepiens, and an appreciable numbers of flies, moths and grasshoppes species. Weekly data showed that most insect preys recovered from these webs included the black legume aphid, Aphis craccivora, however data analysis using chi square test used to show the effect of harvesting on density and activity of spiders, although Analysis of variance (ANOVA) for comparing spread and distribution of spider webs at the field boundary and within the field premises showed significant differences between both groups, indicating that the web-building spiders spin their webs first at the field margins and boundaries of the alfalfa field specially after harvesting alfalfa crop so that they can catch a large portion of insect preys returning to the inside of the alfalfa field. This is evidently followed by remarkable increase in the number of webs displayed with in the premises of the alfalfa field two to three days post-harvesting. |
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Supervisor |
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Prof. Khalid Mohammed Saeed Al-Ghamdi |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1426 AH
2005 AD |
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Added Date |
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Tuesday, June 10, 2008 |
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Researchers
| بندر حمد العوفي | Alofi, Bander Hamad | Researcher | Master | |
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Files
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24145.pdf
| pdf | المستخلص |
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24146.pdf
| pdf | Abstract |
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