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Journal of Insect Conservation

, Volume 17, Issue 1, pp 147–153 | Cite as

The impact of cave lighting on the bioluminescent display of the Tasmanian glow-worm Arachnocampa tasmaniensis

  • David J. MerrittEmail author
  • Arthur K. Clarke
ORIGINAL PAPER

Abstract

Bioluminescent larvae of the dipteran genus Arachnocampa are charismatic microfauna that can reach high densities in caves, where they attract many visitors. These focal populations are the subjects of conservation management because of their high natural and commercial value. Despite their tourism importance, little is known about their susceptibility and resilience to natural or human impacts. At Marakoopa Cave in northern Tasmania, guided tours take visitors through different chambers and terminate at a viewing platform where the cave lighting is extinguished and a glowing colony of Arachnocampa tasmaniensis (Diptera: Keroplatidae) larvae on the chamber ceiling is revealed. Research has shown that exposure to artificial light can cause larvae to douse or dim their bioluminescence; hence, the cave lighting associated with visitor access could reduce the intensity of the natural display. We used time-lapse digital photography to record light output over 10 days to determine whether cave lighting affects the intensity or rhythmicity of bioluminescence. Simultaneously, another colony in a different section of the cave, away from tourist activity, was photographed over 3 days. Both colonies showed high-amplitude 24 h cycling of bioluminescence intensity, with the peak occurring at 11.50 h at the unvisited site and 12.50 h at the main chamber, so the time of peak display did not appear to be substantially affected by light exposure. Intermittent light exposure experienced by larvae in the main chamber caused detectable reductions in bioluminescence intensity; however, recovery was rapid and the overall shape of the daily bioluminescence curve closely matched that of the unvisited colony. In conclusion, the artificial light exposure regime used in Marakoopa Cave does not have a substantial effect on the timing or quality of the bioluminescence display. The time-lapse photographic monitoring method could be permanently implemented at focal tourism sites to provide information about daily, seasonal and annual fluctuations in the displays, the response to events such as drought and flood, and the population’s ability to recover from adverse conditions.

Keywords

Tourism Glow-worm Arachnocampa tasmaniensis Monitoring Circadian rhythms 

Notes

Acknowledgments

We thank Cathie Plowman for help in installing and collecting the camera equipment. We thank Mike Driessen, Paul Flood and Robert Buck of Department of Primary Industries, Parks, Water and Environment, Tasmania for providing cave access, information on lighting and light intensities, permits and accommodation and Rolan Eberhard of Department of Primary Industries, Parks, Water and Environment, Tasmania for discussions, suggestions and encouragement. We thank Joel Levine for providing Matlab functions used in signal analysis.

References

  1. Baker CH (2002) A biological basis for management of glow-worm populations of ecotourism significance. Wildlife tourism research report series. Report no. 21. CRC Sustainable Tourism: Gold CoastGoogle Scholar
  2. Baker CH (2010) A new subgenus and five new species of Australian glow-worm (Diptera: Keroplatidae: Arachnocampa spp.). Mem Qld Mus 55:149–177Google Scholar
  3. Barnes E, Clift W, Garten M, Jinks D, McFarlane C, Sweeney T, Patterson R, Rebgetz J, Waring B (2007) Gold Coast hinterland glow-worm sites: sustainable visitor capacity. Queensland Parks and Wildlife Service. Department of Environment and Resource Management: BrisbaneGoogle Scholar
  4. Broadley RA, Stringer IAN (2001) Prey attraction by larvae of the New Zealand glow-worm, Arachnocampa luminosa (Diptera: Mycetophilidae). Invert Biol 120:170–177CrossRefGoogle Scholar
  5. Clarke A (2001) Glow-worms in Tasmania. Aust Caver 155:17–21Google Scholar
  6. de Freitas CR (2010) The role and importance of cave microclimate in the sustainable use and management of show caves. Acta Carso 39:477–489Google Scholar
  7. Driessen MM (2010) Enhancing conservation of the Tasmanian glow-worm, Arachnocampa tasmaniensis Ferguson (Diptera: Keroplatidae) by monitoring seasonal changes in light displays and life stages. J Ins Cons 14:65–75CrossRefGoogle Scholar
  8. Eberhard R (2000) Reconnaissance Survey of Cave Fauna Management Issues in the Mole Creek Karst National Park, Tasmania. Nature Conservation Report 2000/1. Department of Primary Industry, Water and Environment: HobartGoogle Scholar
  9. Eberhard R, Houshold I, Schilvock V (2004) Mole Creek Karst National Park and Conservation Area Management Plan. Parks and Wildlife Service. Department of Tourism, Parks, Heritage and the Arts, Tasmania: HobartGoogle Scholar
  10. Gatenby JB (1959) Notes on the New Zealand glow-worm, Bolitophila (Arachnocampa) luminosa. Trans R Soc N Z 87:291–314Google Scholar
  11. Kirton LG, Nada B, Khoo V, Phon C-K (2011) Monitoring populations of bioluminescent organisms using digital night photography and image analysis: a case study of the fireflies of the Selangor River, Malaysia. Ins Cons Div. doi: 10.1111/j.1752-4598.2011.00157.x Google Scholar
  12. Lee J (1976) Bioluminescence of the Australian glow-worm, Arachnocampa richardsae Harrison. Photochem Photobiol 24:279–285CrossRefGoogle Scholar
  13. Levine JD, Funes P, Dowse HB, Hall JC (2002) Signal analysis of behavioral and molecular cycles. BMC Neurosci 3:1–25PubMedCrossRefGoogle Scholar
  14. Merritt DJ, Clarke AK (2011) Synchronized circadian bioluminescence in cave-dwelling Arachnocampa tasmaniensis (glow-worms). J Biol Rhythms 26:34–43PubMedCrossRefGoogle Scholar
  15. Meyer-Rochow V (2007) Glow-worms: a review of Arachnocampa spp. and kin. Luminescence 22:251–265PubMedCrossRefGoogle Scholar
  16. Meyer-Rochow VB, Waldvogel H (1979) Visual behaviour and the structure of dark and light-adapted larval and adult eyes of the New Zealand glow-worm Arachnocampa luminos (Mycetophilidae: Diptera). J Insect Physiol 25:601–613CrossRefGoogle Scholar
  17. Pugsley CW (1980) Ecology of the New Zealand glow-worm in caves at Waitomo. PhD thesis. University of AucklandGoogle Scholar
  18. Pugsley C (1984) Ecology of the New Zealand glow-worm, Arachnocampa luminosa (Diptera: Keroplatidae), in the glow-worm cave, Waitomo. J R Soc N Z 14:387–407CrossRefGoogle Scholar
  19. Richards AM (1960) Observations on the New Zealand glow-worm Arachnocampa luminosa (Skuse) 1890. Trans R Soc N Z 88:559–574Google Scholar
  20. Roe D, Leader-Williams N, Dalal-Clayton B (1997) Take only photographs, leave only footprints: the environmental impacts of wildlife tourism. Wildlife and Development Series No 10. The International Institute for Environment and Development: LondonGoogle Scholar
  21. Stringer IAN (1967) The larval behaviour of the New Zealand glow-worm Arachnocampa luminosa. Tane 13:107–117Google Scholar
  22. Thornton N (2003) The effect of environmental conditions on the number of glow-worm lights at two sites in Springbrook National Park, southeast Queensland, Australia (Arachnocampa flava: Diptera: Keroplatidae). Griffith University, BSc Hon thesisGoogle Scholar
  23. Wilson C, Tisdell C, Merritt DJ (2004) Glow-worms as a tourist attraction in Springbrook National Park: Visitor attitudes and economic issues. Working Papers on Economics, Ecology and Environment. Report no. 105. The University of Queensland: BrisbaneGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  1. 1.School of Biological SciencesThe University of QueenslandBrisbaneAustralia
  2. 2.School of ZoologyUniversity of TasmaniaGPO HobartAustralia

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