Journal of Insect Conservation

, Volume 12, Issue 3–4, pp 371–382 | Cite as

Possible rescue from extinction: transfer of a rare New Zealand tusked weta to islands in the Mercury group

  • Ian A. N. Stringer
  • Rob Chappell
Original Paper


The rare Mercury Islands tusked weta, Motuweta isolata (Orthoptera: Anostostomatidae), a large flightless insect originally confined to 13 ha Middle Island in the Mercury Islands, New Zealand, was last seen there in January 2001. Half-grown or larger insects from a captive-breeding programme were released onto nearby Red Mercury Island (34 ♀, 16 ♂) and Double Island (65 ♀, 19 ♂) in 2000 and 2001 to reduce the potential for accidental extinction. Most (108) were released under individual artificial cover objects (ACOs)—clear Perspex discs under plastic plant-pot saucers—and 26 were placed in artificial holes in soil. Usually <10% were found again under ACOs for up to 18 months including 7.5 months as adults. Adults, found in 2005 and 2006, were 1st to 3rd generation island-bred weta (lifespan 1.7–3.2 years). Ongoing monitoring is planned to confirm long-term success. Inbreeding depression is likely so supplementation from Middle Island is required but they may be extinct there. Scraping the soil to expose weta in underground galleries was the best monitoring method. Few were found by searching with lights at night but adults could be located by following other adults equipped with harmonic radar transponders or micro-transmitters.


Relocation Island conservation Monitoring Harmonic radar Radio-tracking 



We are indebted to Graeme Murtagh, Daryl Gwynne and Richard Overwijnk (volunteers); Corinne Watts, Katie Cartner and Chris Winks (Landcare Research Ltd); D. Paul Barrett, Suzanne Bassett, Grant Blackwell, Esta Chappell, Philip Eades, Jens Jorgensen, Matthew Lowe, Melissa Thompson, Mark Fraser and Matthew Wong (Massey University); Katrina Hansen, Maree Hunt, Leigh Marshall, Kahori Nagakawa, Richard Parrish and Greg Sherley (DOC); and Paul A. Barrett (Auckland Zoological Park) for help, often in difficult conditions, with field work. We thank Jens Jorgensen for constructing the predator exclusion cage on Red Mercury Island, Rod Ray (Mercury Seafaris) and Russell Clague (Matarangi Charters) for transport to the island, and Chris Edkins (DOC) for preparing the figures. Many of the methods and ideas originated during discussions with other members of the Tusked Weta Recovery Group—Avi Holzapfel, Chris Green, Chris Smuts-Kennedy, Jason Roxburgh (DOC) and Chris Winks—and we thank them for their contributions and support. We thank Mary McIntyre (University of Otago) for providing unpublished information and advice on tusked weta; and George Gibbs, Chris Green, Ian Mclean, Nicola Nelson and Lisa Sinclair for helpful criticism of the text. Financial support was provided by DOC (Investigation Number 3124) and Massey University.


  1. Allendorf FW, Luikart G (2007) Conservation and the genetics of populations. Blackwell, MaldenGoogle Scholar
  2. Anon (1986) Insect re-establishment—a code of conservation practice. Antenna 10:13–18Google Scholar
  3. Aviss M, Roberts A (1994) Pest fences: notes and comments. Threatened Species Occasional Publication No. 5. Department of Conservation, WellingtonGoogle Scholar
  4. Bell BD (1995) Translocation of fluttering shearwaters: developing a method to re-establish seabird populations. In: Serena M (ed) Reintroduction biology of Australian and New Zealand fauna. Surrey Beatty & Sons Pty Ltd, Chipping Norton, AustraliaGoogle Scholar
  5. Beugnon G, Campan R (1989) Homing in the field cricket Gryllus campestris. J Insect Behav 2:187–198CrossRefGoogle Scholar
  6. Bleakley C, Stringer I, Robertson A, Hedderly D (2006) Design and use of artificial refuges for monitoring adult tree weta, Hemideina crassidens and H. thoracica. DOC Science & Development Series No. 233. Department of Conservation, WellingtonGoogle Scholar
  7. Bowie MH, Hodge S, Banks JC, Vink CJ (2006) An appraisal of simple tree-mounted shelters for non-lethal monitoring of weta (Orthoptera: Anostostomatidae and Rhaphidophoridae) in New Zealand nature reserves. J Insect Conserv 10:261–268CrossRefGoogle Scholar
  8. Cary PRL (1981) The biology of the weta Zealandosandrus gracilis (Orthoptera: Stenopelmatidae) from the Cass Region. MSc, University of Canterbury, ChristchurchGoogle Scholar
  9. Cameron EK (1990) Flora and vegetation of Middle Island, Mercury Island group, eastern Coromandel, northern New Zealand. J Roy Soc N Z 20:273–285Google Scholar
  10. Cameron EK, Hill RL, Bain J, Thomas WP (1993) Analysis of importations for biological control of insect pests and weeds in New Zealand. Biocontrol Sci Technol 3:387–404CrossRefGoogle Scholar
  11. Campbell DJ, Atkinson IAE (1999) Effects of kiore (Rattus exulans Peale) on recruitment of indigenous coastal trees on northern islands of New Zealand. J Roy Soc N Z 29:265–290Google Scholar
  12. Cooper JE (2004) Invertebrate care. Veterin Clin North Am Exotic Anim Pract 7:473–486CrossRefGoogle Scholar
  13. Crane E (1999) The world history of beekeeping and honey hunting. Gerald Duckworth & Co., LondonGoogle Scholar
  14. De Monchy P (2006) Red Mercury Island trip report. Department of Conservation, Coromandel, NZGoogle Scholar
  15. Doube BM, Macqueen A (1991) Establishment of exotic dung beetles in Queensland: the role of habitat specificity. Biocontrol 36:353–360Google Scholar
  16. Fischer J, Lindenmayer DB (2000) An assessment of the published results of animal relocations. Biol Conserv 96:1–11CrossRefGoogle Scholar
  17. Gibbs GW (1990) Report on a visit to Middle Island, Mercury Group, to survey “tusked” wetas, October 1989. Department of Conservation, Wellington, NZGoogle Scholar
  18. Gibbs GW (2002) A new species of tusked weta from the Raukumara Range, North Island, New Zealand (Orthoptera: Anostostomatidae: Motuweta). N Z J Zool 29:293–301Google Scholar
  19. Green CJ (2002) Restoration of tree weta (Orthoptera: Anostostomatidae) to a modified island. In: Veitch CR, Clout MN (eds) Turning the tide: the eradication of invasive species Proceeding of the international conference on eradication of Island invasives. Occasional Paper of the ICUN Species Survival Commission No. 27Google Scholar
  20. Greenfield MD, Alkaslassy G-y, Shelly TE (1989) Long-term memory in territorial grasshoppers. Experientia 45:775–777CrossRefGoogle Scholar
  21. Hale RJ (2000) Nest utilisation and recognition by juvenile gryllacridids (Orthoptera: Gryllacrididae). Aust J Zool 48:643–652CrossRefGoogle Scholar
  22. Hale RJ, Bailey WJ (2004) Homing behaviour of Australian raspy crickets (Orthoptera: Gryllacrididae). Physiol Entomol 29:426–435CrossRefGoogle Scholar
  23. Hayward BW (1986) Origin of the offshore islands of northern New Zealand. In: Wright AE, Beever RE (eds) The Offshore Islands of New Zealand: proceedings of a symposium convened by the Offshore Islands Research Group in Auckland, 10–13 May 1983, Department of Lands and Survey Information Series No. 16. WellingtonGoogle Scholar
  24. Hochkirch A, Witzenberger KA, Teerling A, Niemeyer F (2007) Translocation of an endangered insect species, the field cricket (Gryllus campestris Linnaeus, 1758) in northern Germany. Biodivers Conserv 16:3597–3607CrossRefGoogle Scholar
  25. Holloway GJ, Griffiths GH, Richardson P (2003) Conservation strategy maps: a tool to facilitate biodiversity action planning illustrated using the heath fritillary butterfly. J Appl Ecol 40:413–421Google Scholar
  26. Holway DA, Lach L, Suarez AV, Tsutsui ND, Case TJ (2002) The causes and consequences of ant invasions. Ann Rev Ecol Syst 33:181–233CrossRefGoogle Scholar
  27. Houze CM Jr, Chandler CR (2002) Evaluation of coverboards for sampling terrestrial salamanders in South Georgia. J Herp 36:75–81CrossRefGoogle Scholar
  28. Howarth FG (1991) Environmental impacts of classical biological control. Ann Rev Entomol 36:485–509CrossRefGoogle Scholar
  29. IUCN (1998) IUCN guidelines for re-introductions. IUCN, GlandGoogle Scholar
  30. Jamieson IG, Forbes MR, McKnight EB (2000) Mark-recapture study of mountain stone weta Hemideina maori (Orthoptera: Anostostomatidae) on rock tor ‘islands’. N Z J Ecol 24:209–214Google Scholar
  31. Johns PM (1997) The Gondwanaland weta: family Anostostomatidae (formerly in Stenopelmatidae, Henicidae or Mimnermidae): nomenclatural problems, world checklist, new genera and species. J Orthoptera Res 6:125–138CrossRefGoogle Scholar
  32. Kjoss VA, Litvaitis JA (2001) Comparison of two methods used to sample snake communities in early-successional habitats. Wildl Soc Bull 29:153–157Google Scholar
  33. Leisnham PT, Cameron C, Jamieson IG (2003) Life cycle, survival rates and longevity of an alpine weta Hemideina maori (Orthoptera: Anostostomatidae) determined using mark-recapture analysis. N Z J Ecol 27:191–200Google Scholar
  34. Lettink M, Cree A (2007) Relative use of three types of artificial retreats by terrestrial lizards in grazed coastal shrubland, New Zealand. Appl Herp 4:227–243CrossRefGoogle Scholar
  35. Lettink M, Patrick BH (2006) Use of artificial cover objects for detecting red katipo, Latrodectus katipo Powell (Aranaea: Theridiidae). N Z Entomol 29:99–102Google Scholar
  36. Lockwood JA, Rentz DCF (1996) Nest construction and recognition in a gryllacridid: the discovery of pheromonally mediated autorecognition in an insect. Aust J Zool 44:129–141CrossRefGoogle Scholar
  37. Lövei GL, Stringer IAN, Devine CD, Cartellieri M (1997) Harmonic radar—a method using inexpensive tags to study invertebrate movement on land. N Z J Ecol 21:187–193Google Scholar
  38. Lynch PA, Ferguson EJ, Hynes P (1972) The vegetation of Red Mercury Island. Part 1: the plant communities and a vascular plant species list. Tane 18:21–29Google Scholar
  39. McIlroy JC, Gifford EJ (1997) The “Judas” pig technique: a method that could enhance control programmes against feral pigs, Sus scrofa. Wildl Res 24:483–491CrossRefGoogle Scholar
  40. McIntyre M (2001) The ecology of some large weta species in New Zealand. In: Field LH (ed) The biology of wetas, king crickets and their allies. CAB International Publishing, WallingfordGoogle Scholar
  41. Meads MJ, Notman P (1992) Resurvey for giant wetas (Deinacrida rugosa) released on Maud Island, Marlborough sounds. DSIR land resources technical record 90, Lower Hutt, NZGoogle Scholar
  42. Morris MG, Collins NM, Vane-Wright RI, Waage J (1991) The utilization and value of non-domestic insects. In: Collins NM, Thomas JA (eds) 15th Symposium of the royal entomological society of London 14–15 September 1989. Royal Entomological Society of London, London, pp 319–347Google Scholar
  43. New TR (1995) Needs and prospects for insect reintroductions for conservation in Australia. In: Serena M (ed) Reintroduction biology of Australian and New Zealand fauna. Surrey Beatty & Sons, Chipping Norton, Australia, pp 47–51Google Scholar
  44. New TR, Sands DPA (2004) Management of threatened insect species in Australia, with particular reference to butterflies. Aust J Entomol 43:258–270CrossRefGoogle Scholar
  45. Oats MR, Warren MS (1990) A review of butterfly introductions in Britian and Ireland. Report for the Joint Committee for the Conservation of British Insects founded by the World Wide Fund for NatureGoogle Scholar
  46. Ordish RG (1992) Aggregation and communication of the Wellington weta Hemideina crassidens (Blanchard) (Orthoptera: Stenopelmatidae). N Z Entomol 15:1–5Google Scholar
  47. Priddel D, Carlile N (1995) An artificial nest box for burrow-nesting seabirds. Emu 95:290–294CrossRefGoogle Scholar
  48. Ramsay GW (1978) Seasonality in New Zealand Orthoptera. N Z Entomol 6:357–358Google Scholar
  49. Rivault C, Durier V (2004) Homing in German cockroaches, Blattella germanica (L.) (Insects: Dictyoptera): multi-channelled orientation cues. Ethology 110:761–777CrossRefGoogle Scholar
  50. Samways MJ (1994) Insect conservation biology. Chapman & Hall, LondonGoogle Scholar
  51. Sarrazin F, Barbault R (1996) Reintroductions: challenges and lessons for basic biology. Trends Ecol Evol 11:474–478CrossRefGoogle Scholar
  52. Sherley GH (1998) Translocating a threatened New Zealand giant orthopteran, Deinacrida sp. (Stenopelmatidae): some lessons. J Insect Conserv 2:195–199CrossRefGoogle Scholar
  53. Stringer I (2005) Translocation of the Middle Island tusked weta Motuweta isolata, The Mercury Islands, New Zealand. Conserv Evid 2:83–85Google Scholar
  54. Stringer IAN (2006) Distinguishing tusked weta, Motuweta isolata, from a ground weta, Hemiandrus pallitarsis (Orthoptera: Anostostomatidae) in the field, with observations of their activity on the Mercury Islands, New Zealand. DOC Research & Development Series No 258. Department of Conservation, WellingtonGoogle Scholar
  55. Stringer IAN, Mack H, Grant EA, Winks CJ (2006) Growth and development of captive-reared Mercury Islands tusked weta, Motuweta isolata Johns (Orthoptera: Anostostomatidae). N Z Entomol 29:5–19Google Scholar
  56. Taylor D, Katahira L (1988) Radio telemetry as an aid in eradicating remnant feral goats. Wildl Soc Bull 16:297–299Google Scholar
  57. Towns DR (1994) The role of ecological restoration in the conservation of Whitaker’s skink (Cyclodina whitakeri), a rare New Zealand lizard (Lacertilia: Scincidae). N Z J Zool 21:457–471Google Scholar
  58. Towns DR, Broome KG (2003) From small Maria to massive Campbell: forty years of rat eradications from New Zealand islands. N Z J Zool 30:377–398Google Scholar
  59. Towns DR, Atkinson IAE, Daugherty CH (1990) The potential for ecological restoration in the Mercury Islands. In: Towns DR, Daugherty CH, Atkinson IAE (eds) Ecological restoration of New Zealand Islands. Conservation Sciences Publication No. 2, Department of Conservation, WellingtonGoogle Scholar
  60. Townsend JA (1995) Distribution and ecology of the Banks Peninsula tree weta, Hemideina ricta. MSc, Massey University, Palmerston NorthGoogle Scholar
  61. Trewick SA, Morgan-Richards M (2000) Artificial weta roosts: a technique for ecological study and population monitoring of Tree Weta (Hemideina) and other invertebrates. N Z J Ecol 24:201–208Google Scholar
  62. Ussher G (1998) Introduction of northern tuatara to Moutohora Island, Bay of Plenty. Ecol Man 6:23–33Google Scholar
  63. van Wyngaarden F (1995) The ecology of the Tekapo ground weta (Hemiandrus new sp.; Orthoptera: Anostostomatidae) and recommendations for the conservation of a threatened close relative. MSc, University of Canterbury, ChristchurchGoogle Scholar
  64. Wakelin M, Smuts-Kennedy C, Thurley T, Webster N (2003) Artificial cover objects for leiopelmatid frogs. DOC Internal Science Series No. 120. Department of Conservation, WellingtonGoogle Scholar
  65. Winks C, Ramsay G (1998) Captive rearing of the Middle Island tusked weta. Research Contract Report LC9899/10, Department of Conservation, WellingtonGoogle Scholar
  66. Winks CJ, Fowler SV, Ramsay GW (2002) Captive-rearing of the Middle Island tusked weta. Science for Conservation 197. Department of Conservation, WellingtonGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  1. 1.Department of ConservationWellingtonNew Zealand
  2. 2.Department of ConservationCoromandelNew Zealand

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