Reproductive activity of Onthophagus granulatus Boheman (Coleoptera: Scarabaeinae) in New Zealand: Implications for its Effectiveness in the Control of Pastoral Dung

• Published in: New Zealand entomologist Vol. 32; no. 1; pp. 76 - 84
• Main Author: Forgie, Shaun A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-02-2009
• Subjects: Beetles; development; Dispersal; dung; Dung beetles; dung burial; Entomology; Insects; maturation; nidifi cation; oocyte; over wintering; resorption
• ISSN: 0077-9962; 1179-3430; 1179-3430
• DOI: 10.1080/00779962.2009.9722179

Reproductive condition and breeding cycles of adult female O. granulatus were demonstrated in field collected insects using physiological age-grading techniques to assess the proportions of newly emerged, nulliparous and parous beetles and those resorbing oocytes. Northern New Zealand populations of the dung beetle were univoltine. Breeding and dung burial started in early September and was maintained continuously until March with a late January peak in brood ball production (nidifi cation) coinciding with the greatest abundance of adults. Adults ceased reproductive development at the onset of winter, during which females maintained ovariole condition at nulliparous stage two (N2). Brood mortality was greatest in early spring and late autumn, resulting from the effects of low soil temperature and high soil moisture. Nidification activity of O. granulatus and its effect on the amount of dung remaining on the surface of pasture is discussed in terms of its efficacy of removal of livestock dung.