Field establishment of dung beetles in South Australia

Summary

Project B.ERM.0213 imported the spring-active dung beetles Onthophagus vacca and Bubas bubalus from Europe to fill a gap in dung beetle activity in early spring across southern Australia. The beetles were reared by CSIRO. Small numbers were released to high-care field nurseries in South Australia in spring 2014 (Project B.ERM.0214). Projects B.ERM.0216 and B.ERM.1102 deal with the transfer of these species to the field and to mass rearing facilities in WA and NSW.

Newly emerged O. vacca adults were fed in the field nurseries from December 2016 to April 2017, when they stopped feeding and entered diapause. A small number bred in late summer, producing an autumn emergence, the second generation in a year. All adult B. bubalus had died by February 2017, leaving larvae underground. Monitoring of the spring emergence began in July 2017. Newly emerged beetles were transferred to new nurseries.

The planned field release of the beetles was cancelled in favour of breeding beetles. One field release of 1,100 adult O. vacca occurred in Manjimup, Western Australia. The remaining beetles were released for mass rearing in WA (2,089 O. vacca; 185 B. bubalus) and at Armidale, New South Wales (2,453 O. vacca).

Mass rearing of O. vacca and B. bubalus will not continue at Strathalbyn beyond the term of Project B.ERM.0216.