Decomposition of organic matter and soil nitrogen (N) cycling is a key process in soil fertility. In arid ecosystems, plant litter remains intact for long periods and is gradually consumed by macrodetritivore arthropods. It is suggested that tenebrionid beetles are responsible for most of nutrient cycling from accumulated litter in warm and dry seasons in arid ecosystems. The objective of this work was to extent the role on soil fertility and N cycling to Nyctelia dorsata Fairmaire (Coleoptera: Tenebrionidae) throughout litter fragmentation and consumption in a manipulative pot experiment. Our results showed that litter presence alone is not enough to incorporate N to the soil. N. dorsata consumed a significant fraction of litter and this activity was associated to an increase in soil N contents in the experimental pots. These confirmed that several tenebrionid species positively affects soil fertility in Northeastern Patagonia throughout litter fragmentation/consumption; and that these effects may vary with body size. Consequently, these beetles might be very important into the food/energy web from plants to higher trophic levels in this region.