Diversity and relative abundance of spider species occurring on different strata of citrus trees at Samundari [Pakistan]
2001
Zafar, A.
This study was carried out from September 2000 through August 2001 in a citrus orchard located in Sumandari Tehsil of Faisalabad District. The foliage of 62 citrus trees of this orchard was jarred for obtaining the sample of spiders. This process was continued for ten consecutive days each month. The specimens of the spiders caught from the three crown levels top, middle and bottom during each month were preserved separately. A total of 2050 spiders were collected from all the three levels of the crown of the trees. In this sample, 10 families, 23 genera and 45 species, of spiders were represented. On the basis of the numerical superiority in the monthly and pooled samples 5 dominant species of spiders were recognized. These species, in order of dominance were Oxyopes azhari, Oxyopes sheweta, Thomisus cheraponjiesis, Marpissa pseudodacoratus and Neoscona mukerji. Jointly, these dominant species maintained high abundance in almost all the four seasons of the year. For example, species Oxyopes azhari, Oxyopes sheweta and Thomisus cheraponjiesis maintained high number in summer, species, Marpissci pseudodacoratus, Oxyopes azhari and Neoscona mukerji in fall, species Thomisus cheraponjiesis, Oxyopes azhari and Malpissa pseudodacoratus in winter and species Oxyopes azhari, Oxyopes sheweta and Malpissa pseudodacoratus in spring. In the monthly samples (one twig each from the three levels of the citrus tree crowns) the number of spiders varied from 105 to 226. It was estimated that an average citrus tree supported as population of 11 to 28.5 spiders.
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