Dung and gatrointestinal nematode eggs buried by Euoniticellus intermedius (Reiche) (Coleoptera: Scarabaeidae: Scarabaeinae)

The phenology of the dung beetle Euoniticellus intermedius (Reiche) was studied under field conditions, along with two main environmental services: the quantity of dung buried per beetle under controlled insectarium conditions; and the monthly abundance of nematode eggs in cattle dung that had not been treated with anti-helminthics. Euoniticellus intermedius was very abundant during the rainy season. Similarly, the highest number of nematode eggs was found during the rainy season. Recently emerged E. intermedius in the laboratory buried daily less than half the dung (0.91 +/- 0.16 grams) buried by mature individuals (2.17 +/- 0.04 grams). During the rainy season, each recently emerged beetle buried an average of 53.7 nematode eggs, and each mature beetle buried 128 eggs. During the dry season, each recently emerged beetle buried on average 4.6 eggs, whereas mature beetle buried on average 10.9 eggs. Our results show that the quality of environmental services provided by E. intermedius is dependent on the season and age of dung beetles. We recommend that cattle not be dewormed during the dry months of the year, as the risk of nematode transmission to cattle is low, while the threat of parasiticides on the dung fauna and associated ecosystem services is high.