Onthophagus vacca
Identifying features
​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.
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Distribution
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.
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Additional Information
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.
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