Spider assemblage in olive groves in southern of Brazil

Spiders represent an abundant group of predators within the agroecosystems, and in olive groves of Europe spiders are important predators and may significantly reduce the attack of pests. In Brazil there are only few investigations that study the assembly of spiders in agroecosystems. This research aimed to characterize the assembly of spiders in olive groves in Rio Grande do Sul. The study was conducted from October 2010 to October 2012, in five groves of the Municipalities of Pelotas, Bagé, Rio Grande, Cachoeira do Sul and Santana do Livramento. Spiders were monthly collected from the tree canopy by beating tree branches using a modified japanese umbrella device. Two samples per tree were taken (one on the shaded face and another on the sunny face). Each sample took 10 seconds, so 400 seconds were spent in 20 plants of each olive grove. The faunal analysis of the results was performed by determining dominance, abundance, frequency and constancy of species. It was obtained a wealth of 38 species of spiders distributed in 10 families. The predominant species were Sphecozone sp.1 and sp.2, Anelosimus studiosus, Eustala sp.1, Cheiracanthium inclusum, Misumenops sp.1, Sanogasta sp.2, and morphospecies sp.1 (Salticidae).