1. St. John’s wort beetles would not have been introduced to NZ today! Ronny Groenteman, Simon Fowler & Jon Sullivan

2. St. John’s Who???

3. St. John’s wort Hypericum perforatum Introduced as medicinal herb Severe pasture weed by 1930s Toxic to live stock Programme started 1943 Most successful BC programme

5. BC agent removal trial Insecticide Water

6. St. John’s wort biocontrol Why invest funds in an old successful programme??? Post-release studies are pivotal to advance BC practice: –Safety –Effectiveness –Economics

7. Objectives Compare host-tests predictions to real world Demonstrate significance of BC agents Implications for future programmes

8. Retrospective host-range tests Indigenous species not included in original tests 4 indigenous species –2 endemic –1 critically threatened

9. H. involutum NZ Australia

10. H. rubicundulum NZ endemic

11. H. pusillum NZ Australia

12. We asked: Would we have introduced St. John’s wort beetles today?

13. Methods Laboratory host range testing No-choice / choice arenas Feeding Development Oviposition

14. Results H. perforatumH. involutumH. pusillum Days to end of larval stage 0 10 20 30 40 50 60 H. perforatumH. involutumH. pusillum % completed development 0 20 40 60 80 100 C. hyperici C. quadrigemina H. perforatumH. involutumH. pusillumH. rubicundulumH. androsaemum Eggs per plant 0 5 10 15 20 25 30 35 Groenteman et al., 2011. Biological Control

15. Larval development H. perforatum H. involutum H. androsaemum H. rubicundulum H. pusillum

16. In reality… Little evidence of damage to indigenous species Significant displacement? Yet to be determined Benefits of control - enormous

17. Recent review of successful programmes in N. America concluded: –St. John’s wort beetles would not have been introduced nowadays –More stringent regulations / interpretation of old regulations –Monitoring crucial for data-driven benefit-risk decisions Global context

18. Implications Risk rejecting effective & safe agents Control goals? Implications of failure to control?

19. USDA ARS - European Biological Control Laboratory, Bugwood.org St. John’s wort beetles success