Dung accumulation along the drainage area of Salado River leads to the problem of loss of areas dedicated to cattle feeding, as well as the loss of soil nutrients, and an increasing accumulation of parasites. There exists an entomofauna which proves to be potentially benefic for the elimination of pollution in the fields and for the prevention of cattle parasites. Among the entomofauna, we find coprophagous (dung-eating) and coprophylous scarabs, being Ontherus sulcator
F. (Coleoptera Scarabaeidae) the most abundant and active. With the purpose of studying the importance of this insect in the incorporation of dung into the soil, a test was carried out with 24 recipients filled with soil and 1 kg of dung. 20 scarabs per bucket were added to 18 of these recipients and after 7 days the remaining dung of each bucket was weighted. The Student t test was used in order to compare the measures in both groups. The results showed highly significant differences (P<0.001). From this result we understand that Ontherus sulcator
F. ( Coleoptera Scarabaeidae) is a potential ally for the farmer of the Salado River drainage area, because it has a very particular feature. It makes use of the bovine defecation as a substratum for its own feeding and for its descendants, causing the dung to disappear quickly from the field surface.