Distribution of ground dwelling spider genera among berseem crop at Okara district, Pakistan
By: Muhammad Arshad Rana, Munaza Shabnam, Naureen Rana, Tayyba Sultana, Salma Sultana, Sobia Kanwal, Imran Ahmad
Key Words: Ground dwelling, Spider, Pitfall, Population, Transect.
J. Bio. Env. Sci. 8(2), 104-113, February 2016.
The present study was designed to record the distribution of ground dwelling spider genera among berseem crop at Okara district. Sampling was made from Trifolium crop on fortnight basis through pitfall traps. Equal number of traps were placed in three rows e.g. along the boundary, middle of the field and centre of the field. Each trap was filled with mixture solution of alcohol and glycerin (70:30%) along with few drops of kerosene oil. After 5 days interval sample traps was collected and spider specimens were washed with distilled water and permanently stored in labeled glass vials, and brought into the Pest Control Laboratory, Departmentof Zoology, Wildlife and Fisheries, University of Agriculture, Faisalabad. Thereafter, each spider specimen was identified according to the taxonomic material and internet source. Identified data was analyzed statistically to quantify their spatial distribution. Overall maximum spatial distribution of spider population was documented in middle transect than boundary and centre of the berseem crop. It was also observed that temperature, humidity, vegetation and prey availability were the major factors that effecting the spider population. Population variations were recorded during the months of February, March and April in 2015, due to rise of temperature, decrease of humidity and availability of prey. It was concluded that despite to cosmopolitan nature, spiders have some correlation with suitable local conditions or habitat. More over, spiders are cost effective, functionally significant and play a key role in regulating decomposer population.