This study aimed to evaluate the arthropod fauna associated with pecan trees [Carya illinoinensis (Wangenh.) K. Koch] (Juglandaceae) in the south of Brazil. The experiment was conducted in a C. illinoinensis plantation of approximately 1.2 hectares, divided into 7 m × 7 m areas that were subjected to different soil preparations and pit sizes, in Santa Maria, RS, Brazil. A randomized block design with five blocks and four treatments was used: planting in small pits of 20 cm × 60 cm (Sp); using a subsoiler with a leveling grader/shank and small pits (Ssp); using a rotary tiller and small pits (Tsp); and planting in large pits of 40 cm × 60 cm (Lp). Eighteen biweekly samplings were carried out from March 2014 to May 2015 using yellow adhesive traps in all treatment areas. No statistically significant difference in abundance or arthropod richness was observed. The population peak of Monellia caryella (Fitch) (Aphididae) occurred in April 2014. After the population growth of M. caryella, an increase in Coccinellidae in the traps was observed. It can be concluded that the different soil preparations and pit sizes proposed for pecan planting do not affect the diversity of the arthropods collected using yellow adhesive traps.