EFFECTS OF FORMALIN TREATMENT AND DUNG CONSISTENCY ON HATCHING AND ESTABLISHMENT OF LARVAE OF ONTHOPHAGUS-TAURUS (SCHREBER), BUBAS-BISON (L) AND ONITIS-BELIAL (F) (COLEOPTERA, SCARABAEIDAE)

As part of a program concerned with the introduction of exotic dung be etles to Australia, eggs of three species of dung beetle (Onthophagus taurus, Bubas bison and Onitis belial) were immersed for 3 min in 1% f ormaldehyde (ca 3% formalin), followed by rinsing in ammonium carbonat e and/or reverse osmosis water to neutralise or remove formaldehyde-re sidues. In all three species, formaldehyde treatment had no adverse ef fects on either egg survival or larval establishment, irrespective of the type of post-immersion rinse. Species effects and effects associat ed with the nature of the dung on which the eggs were placed after tre atment were the main factors determining egg and larval survival. O. t aurus was the most robust species, with 82.5% of individuals reaching pupation regardless of treatment. This compared with 18.5% For B. biso n and 0% for O. belial. An alternative method of satisfying requiremen ts for release from quarantine is suggested for species such as O. bel ial.