DUNG BEETLE SPECIES
Onthophagus vacca is a small beetle (7 – 13mm) with a shiny metallic green or bronze pronotum and head. Wing covers are pale orange-brown with occasional dark markings. The legs are black. Both sexes have a distinct ridge on the head in front of the eyes – more pronounced in females. Males have a large single lamina (part of the optic lobe) on the head, ending in a single point. There is a large indentation at the front of the pronotum. Females’ lamina ends in two points and have a projection at the front of the pronotum.
Onthophagus vacca is distributed throughout southern Europe and into Asia. In Western Australia, trial colonies have been released in Manjimup and Youngs Siding with ongoing monitoring to determine establishment.
Onthophagus vacca is a day flying beetle. It is expected to emerge and begin laying eggs from September onwards. It is active until mid-summer. Onthophagus vacca is generally considered to have one generation a year. Information of the Onthophagus vacca breeding behaviour in Australia is being documented to gain a more accurate understanding of their breeding in the southern hemisphere. This is necessary to overcome previous failed attempts at introducing the species to Australia.