1. P Peterson 1, SV Fowler 2, M Merrett 3 and P Barrett 4 1 LCR, PN, 2 LCR, Chch, 3 The Open Polytechnic of NZ, Lower Hutt, 4 Massey University, PN Heather beetle impact assessment

2. Heather (Calluna vulgaris)

3. Spreading - Te Aroha - Rotorua - Tarawera - Pureora - Mt Egmont National Park - Hokitika - Mt Cook - Queenstown - Te Anau · · · · · · · · · ·

10. Photo by Shaun Forgie Heather beetle (Lochmaea suturalis)

11. Impact assessment

12. Assessment area

13. Treatments: Herbicide (2,4-D ester) Heather beetle Control Beetle vs herbicide Design: 3 treatments 4 blocks 2 reps per block

14. Vegetation cover Pre-treatment 50 x 50 cm Merilyn Merrett estimating vegetation cover

15. 37 vascular species 37 vascular common 25 dicot species 20 native 5 exotic 12 monocot species 8 native 4 exotic 9 vascular uncommon Native and exotic, i.e. sedges, lilies, grasses, etc.

16. Applied treatments

17. No beetle establishment Herbicide impacts were interesting Beetle vs herbicide

18. 2002–2011 Herbicide only assessment Before and after photos

19. Control 2011 Herbicide 2002

20. Heather (Calluna vulgaris)

22. Monoao (Dracophyllum subulatum)Sprawling coprosma (C.cheesemanii) Mountain heath (Pentachondra pumila)Tauhinu (Ozothamnus leptophylla) Native dicotyledons

24. Hawkweed (Pilosella officinarum)

26. All monocotyledons Browntop (Agrostis capillaris)Yorkshire fog (Holcus lanatus) Red tussock (Chionochloa rubra)Silver tussock (Poa cita)

28. Red tussock (Chionochloa rubra)

30. Browntop (Agrostis capillaris)

32. Summary (herbicide only assessment) Four herbicide applications kill 80% of heather but signs of recovery 4 years later Heather may recover faster than dicot natives? Monocot cover (both native and exotic) increases following herbicide application Heather cover doubled in 9 years if nothing was done

33. Summary (herbicide only assessment) Four herbicide applications kill 80% of heather but signs of recovery 4 years later Heather may recover faster than dicot natives? Monocot cover (both native and exotic) increases following herbicide application Heather cover doubled in 9 years if nothing was done

34. Summary (herbicide only assessment) Four herbicide applications kill 80% of heather but signs of recovery 4 years later Heather may recover faster than dicot natives? Monocot cover (both native and exotic) increases following herbicide application Heather cover doubled in 9 years if nothing was done

35. Summary (herbicide only assessment) Four herbicide applications kill 80% of heather but signs of recovery 4 years later Heather may recover faster than dicot natives? Monocot cover (both native and exotic) increases following herbicide application Heather cover doubled in 9 years if nothing was done

36. But what about the beetles?

37. Difficult to establish Released (1996–2009) 36 000 all stages 78 sites Establishment 9 outbreaks (9%) 2 false starts

38. Impact assessment (beetle vs herbicide – 2 nd attempt)

39. Assessment area

40. Beetle vs herbicide Beetle feeding damage visible in 2007

41. 2007 Small heather beetle outbreak

42. Plots set up outside beetle-damaged area 2007

43. I H+I H 4 treatments, 6 blocks assigned 2007

44. 2007– ? I H+I H Predicted beetle dispersal

45. Vegetation cover Pre-treatment 50 x 50 cm Merilyn Merrett estimating vegetation cover

46. 32 vascular species 32 vascular common 25 dicot species 21 native 4 exotic 7 monocot species 5 native 2 exotic 15 vascular uncommon Native and exotic, i.e. sedges, lilies, orchids, grasses, etc.

47. Applied treatments TreatmentCodeEffect Do nothingBeetle impact Spray insecticide (Karate zeon: lambda-cyhalothrin) IHeather protected Spray herbicide (Pature Kleen: 2,4-D ester ) HBeetle + Herbicide impact Spray herbicide + insecticideH+IHerbicide impact

49. 2008

50. 2009

55. Unsprayed (heather beetle impact)Herbicide (beetle + herbicide impact) Insecticide (heather protected)Herbicide + insecticide (herbicide impact)

56. Initial observations Almost all heather dead following beetle feeding and/or 3 herbicide applications No non-target damage from beetle feeding Again, significant non-target damage from herbicide application to dicots

58. Initial observations Almost all heather dead following beetle feeding and/or 3 herbicide applications No non-target damage from beetle feeding Again, significant non-target damage from herbicide application to dicots

59. Dracophyllum subulatum Chionochloa rubraCoprosma cheesmanii Pentachondra pumila

60. Initial observations Almost all heather dead following beetle feeding and/or 3 herbicide applications No non-target damage from beetle feeding Again, significant non-target damage from herbicide application to dicots

61. Dracophyllum subulatum

62. Vegetation cover post-treatment (2009 & 2010) 50 x 50 cm Merilyn Merrett estimating vegetation cover

63. Heather (Calluna vulgaris)

65. Monoao (Dracophyllum subulatum)Sprawling coprosma (C.cheesemanii) Mountain heath (Pentachondra pumila)Tauhinu (Ozothamnus leptophylla) Native dicotyledons

67. Mouse-ear hawkweed (Pilosella officinarum) Catsear (Hypochoeris radicata)Lotus major (Lotus pedunculatus) Exotic dicots minus heather

69. All monocotyledons Browntop (Agrostis capillaris)Yorkshire fog (Holcus lanatus) Red tussock (Chionochloa rubra)Silver tussock (Poa cita)

71. Red tussock (Chionochloa rubra)

73. Browntop (Agrostis capillaris)

75. Summary (beetle vs herbicide) Beetle feeding kills 99% of heather vs 90% after 3 herbicide applications No non-target damage from beetle feeding but significant damage to dicots from herbicide application Some evidence for dicot response after beetle feeding but too early to be sure All monocots trending upwards following heather removal by either method

76. Summary (beetle vs herbicide) Beetle feeding kills 99% of heather vs 90% after 3 herbicide applications No non-target damage from beetle feeding but significant damage to dicots from herbicide application Some evidence for dicot response after beetle feeding but too early to be sure All monocots trending upwards following heather removal by either method

77. Summary (beetle vs herbicide) Beetle feeding kills 99% of heather vs 90% after 3 herbicide applications No non-target damage from beetle feeding but significant damage to dicots from herbicide application Some evidence for dicot response after beetle feeding but too early to be sure All monocots trending upwards following heather removal by either method

78. Summary (beetle vs herbicide) Beetle feeding kills 99% of heather vs 90% after 3 herbicide applications No non-target damage from beetle feeding but significant damage to dicots from herbicide application Some evidence for dicot response after beetle feeding but too early to be sure All monocots trending upwards following heather removal by either method

79. Conclusions ( both experiments) Both methods are effective for killing heather Herbicide non-target impacts can significantly alter vegetation composition after 9 years More time required to assess full impact of heather removal by beetle feeding but no non-target damage seen Exotic monocot invasion seems inevitable using either method if close to a seed source Doing nothing will result in more heather

80. Conclusions ( both experiments) Both methods are effective for killing heather Herbicide non-target impacts can significantly alter vegetation composition after 9 years More time required to assess full impact of heather removal by beetle feeding but no non-target damage seen Exotic monocot invasion seems inevitable using either method if close to a seed source Doing nothing will result in more heather

81. Conclusions ( both experiments) Both methods are effective for killing heather Herbicide non-target impacts can significantly alter vegetation composition after 9 years More time required to assess full impact of heather removal by beetle feeding but no non-target damage seen Exotic monocot invasion seems inevitable using either method if close to a seed source Doing nothing will result in more heather

82. Conclusions ( both experiments) Both methods are effective for killing heather Herbicide non-target impacts can significantly alter vegetation composition after 9 years More time required to assess full impact of heather removal by beetle feeding but no non-target damage seen Exotic monocot invasion seems inevitable using either method if close to a seed source Doing nothing will result in more heather

83. Conclusions ( both experiments) Both methods are effective for killing heather Herbicide non-target impacts can significantly alter vegetation composition after 9 years More time required to assess full impact of heather removal by beetle feeding but no non-target damage seen Exotic monocot invasion seems inevitable using either method if close to a seed source Doing nothing will result in more heather

84. Acknowledgements We would like to thank John Mangos (New Zealand Army) for continued support, Lawire Cairns for aerial photography, and Lindsay Smith (LCR) and Andrew Blayney (Massey University) for help with field work. This project has been funded by the Ministry for Science and Innovation (formally the Foundation for Research, Science and Technology) Contract No. C09X0210, and the New Zealand Army.

85. Scale of beetle feeding impact

86. 1 km

87. 2001–2004.

88. 1 km. 2005 (1 m²)

89. 1 km. 2006 (25 m²)

90. 1 km 2007 (¼ ha).

91. 1 km 2008 (1½ ha).

92. 1 km 2009 (4½ ha).

93. 1 km 2010 (17 ha).

94. 1 km 2011 (80 ha).