At present both Onthophagus deterrens and O. variolosus are accepted as valid species, but this status requires confirmation through comparison of the types as O. variolosus may simply be a colour morph of O. deterrens as presently understood (Davis et al.2020).

This species is listed as Least Concern on the basis that it is widespread and unlikely to be threatened.

This species is apparently endemic to South Africa, although may occur in Lesotho. It ranges widely along the south Cape coast and is also known inland from sites along the northwest border of Lesotho (Davis et al. 2020). It ranges from 26 to 1,830 m asl. (Davis et al. 2020).

There is inadequate population information available for this species. It is recorded with relatively high frequency (A. Davis pers. comm. 2023).

There is little ecological data for this species. Davis et al. (2020) summarise a total of three soil, two vegetation and five dung records combining data for both this species and Onthophagus deterrens. Records have been taken from sandy loam and sandy clay loam in pasture/grassland, primarily within fynbos vegetation units within highveld grassland vegetation units (Davis et al. 2020). Records have been taken from dog dung and from carrion (one record from a toad and two from arthropods) (Davis et al. 2020). The species is day-flying, and active between September and April during the summer rainy season (Davis et al. 2020).

Across 16 localities mean annual rainfall is between 270 and 879 mm and mean annual temperature between 13.3–17.8 °C (Davis et al. 2020).

This species has a wide range and the limited available data suggest both adaptability to pastoral activity and a possible association with carrion and carnivore dung, a readily available resource. It is consequently unlikely to be threatened.

This species is unlikely to be utilised.

This species is not known from any protected areas. Taxonomic research is needed to clarify relationships between this species and Onthophagus deterrens (Davis et al. 2020). Quantitative data are required to clarify this species' ecological associations (Davis et al. 2020).