Malesian Butterflies
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Malesian Butterflies
Troides helena Linnaeus, 1758

CONSERVATION

IUCN Redlist category
Least Concern (IUCN 2020)

Rationale for redlist categorization
Troides helena has been assessed as Least Concern. This species has a wide extent of occurrence, being found across South and Southeast Asia. It is often found in good numbers within its range and its occurrence in a range of vegetated habitats suggests that habitat loss may not impact the species as severely as other birdwing butterflies. As such it is currently not thought to undergo any declines. (IUCN 2020)

Threat category
Ecosystem conversion|Ecosystem degradation,Species mortality (IUCN 2020)

Cause of stress
Intentional use (species is the target) (IUCN 2020)

Described Threats
The species is listed on CITES Appendix II together with the genera Ornithoptera and Trogonoptera , with the exception of O. alexandrae which is listed on Appendix I. Recently traded individuals appear to come mostly from captive or ranched populations (CITES 2015). Butterfly ranching is generally thought of as a sound, economically viable and sustainable rural industry (Wambi 1996, Hanscom 1993, Burrows 2003 in Small 2007). However, there are concerns that butterfly ranching may not be as sustainable in some countries as it is often perceived to be (e.g., Papua New Guinea; Small 2007). This is based on a lack of data and species monitoring to assess the status of butterfly populations, and for many species, such monitoring is fraught with difficulty due to inaccessibility of their habitat (Small 2007). New and Collins (1991) noted that trade is extremely difficult to monitor because transportation of unpinned specimens is easy, especially of comparatively low value species which may instead be traded at high volumes. It has been stated that overcollecting seldom becomes a threat to butterflies, due to the reproductive capacity of insects and the difficulty in capturing significant numbers of the population (Pyle and Hughes 1978, in Parsons 1992). However, where birdwing butterflies are highly specific to host plants and where density of these hosts plants limits population size, collection in conjunction with habitat loss could have significant impacts on the species or subpopulations. Given the species' occurrence in a range of vegetated environments, it is likely that it is less susceptible to habitat loss than other species of birdwing butterfly. However, habitat loss is likely to have a localized effect on the species in parts of its range. For example, scarcity of the species prompted studies in the Forest Park of Mount Tumpa, North Sulawesi, into visit frequency of the species to this conservation site (Pontororing et al. 2016). In Nepal, destruction of forest habitat especially at lower altitudes is thought to contribute to low population numbers of this species (B. Khanal pers. comm. Feb. 2018). (IUCN 2020)

Commercial use
Butterflies are mostly traded dead for the curio market (Collins and Morris 1985, New and Collins 1991). Between 1998 to 2007, 306,000 butterflies were traded from Southeast Asia, with 13,000 of these being wild-caught (Nijman 2010). There is a distinct shift towards ranched and captive-bred individuals in trade from 2003 onwards; in 1985, it was reported that globally less than 10% of trade was in ranched individuals (Collins and Morris 1985). Altogether at least 34 different species were recorded in trade, most of which belonged to the birdwing butterflies ( Troides and Ornithoptera ; Nijman 2010). It should be noted that trade in butterflies may be underreported, because of difficulties monitoring. New and Collins (1991) noted that trade is extremely difficult to monitor because transportation of unpinned specimens is easy, especially of comparatively low value species which may instead be traded at high volumes.

Birdwings can fetch high prices on the market. For example, butterfly collectors have paid high prices for birdwing butterflies of this genus: a pair of Ornithoptera meridionalis was reported to have fetched USD 3,400 in Germany (Melisch and Schutz 2000). Reported prices for Troides are however much lower. The more recent pricing for this species was around $15 per individual (Putri 2016). This species is listed on Appendix II of CITES. Recent data from the CITES Trade database show that since 2000 and 2015 around 79,000 individuals were exported from range countries, nearly all from Indonesia and Malaysia (UNEP-WCMC 2012; 76% and 24%, respectively; CITES 2015). Of these, less than 1% of individuals traded from Indonesia come from wild populations, and around 13% of individuals traded from Malaysia; ranching and captive breeding are the most prominent sources for traded individuals (CITES 2015). The species was reported in local trade in Bantimurung Nature Recreation Park, as preserved butterflies, in key chains and frames (Putri 2016). (IUCN 2020)

Applied conservation actions
The species was not thought to be threatened in a previous status assessment of the world's swallowtail butterflies (Collins and Morris 1985). However, within parts of its range, it is considered to be potentially vulnerable to extinction (e.g. Singapore; Khew and Neo 1997). In Bangladesh, for example, the species was assessed as Vulnerable (Hossain 2015). In Nepal, a status assessment made in 1995 included the species as Susceptible (threat code 5) into the National Red Data Book of Nepal (NRDB 1995). The species is protected in Indonesia (Vane Wright and de Jong 2003). In Hong Kong, this species and one of its host plants, Aristolochia tagala , are under legal protection (P. Lo pers. comm. Feb. 2018). It is also protected - in addition to its CITES listing - under Government Regulation No. 7 of 1999 and Annex B of the European Union Wildlife Trade Regulation; it is also classed as a species of high conservation priority in the Forestry Minister Regulation No. 57 of 2008 (Putri 2016). This species occurs in many protected areas, including for example Gorumara National Park in West Bengal (Department of Forests 2013), Imbak Valley forest reserve (Jalil et al., 2008), Endau Rompin National Park in Johor (Zaidi et al., 2009) and nature reserves within Singapore (Khew and Neo 1997). It also occurs in Bantimurung Nature Recreation Park (Noerdjito and Amir 1992 in UNEP-WCMC 2012, Putri 2016); however, interview data with collectors between 1970s and present suggest that in this area at least, butterfly abundances have declined over time due to collection. There is a call for better enforceable legislation on collecting of butterflies in this and the wider region to ensure that butterfly populations are sustained into the future (Putri 2016). In Hong Kong, Aristolochia tagala has been planted in Kadoorie Farm and Botanic Garden, a private nature reserve, as a conservation measure for this species and this action has had notable success (Kiu et al. 2007). In addition, a site in Hong Kong was designated as a Site of Special Scientific Interest in 1980 because it is an important breeding site of rare butterflies, including this species (Wang et al. 2003). In Vietnam, the species was reported from the following protected areas: Na hang Nature Reserve, Ba Be National Park, Tam Dao National Park, Ba Vi National Park, Cuc Phuong National Park, Cat Ba National Park and Bai Tu Long National Park in Northern Vietnam; Pu Huong Nature Reserve, Pu Mat Nature Reserve, Ben En National Park, Xuan Lien Nature Reserve, Vu Quang National Park, Bach Ma National Park, Phong Dien Nature Reserve, Kon Plong State Forest Enterprise, Chu Yang Sin National Park, Nui Chua Nature Reserve, Bi Doup Nui Ba National Park and Da Teh State Forest Enterprise in Central Vietnam; and Cat Tien National Park in Central and Southern Vietnam (Monastyrskii 2007). Studies in North Sulawesi suggests that increasing the number of food vines available within the habitat and planting of nectaring flowers increases butterfly visits to the site (Pontororing et al. 2016). While there is overall comparatively lots of information available for this species compared to other birdwing butterflies, in parts of its range (e.g. Nepal) detailed study on the population status of this species is still lacking (B. Khanal pers. comm. Feb. 2018). (IUCN 2020)

REFERENCES

  • CITES. 2015. CITES Trade Data Base. Available at: http://trade.cites.org/.
  • Collins, N.M. and Morris, M.G. 1985. Threatened Swallowtail Butterflies of the World. The IUCN Red Data Book. IUCN, Gland and Cambridge.
  • Department of Forests, Government of West Bengal. 2013. Butterflies of Gorumara National Park: a pictorial guide. Wildlife Division II, Jalpaiguri.
  • Hanscom, T. 1993. Setting hearts aflutter: little butterflies take wing as big business. The Rotarian 163: 16-19.
  • Hossain, M.M. 2015. Troides helena. IUCN Bangladesh. Red List of Bangladesh Volume 7: Butterflies, pp. 236. IUCN, International Union for Conservation of Nature, Bangladesh Country Office, Dhaka.
  • IUCN. 2020. The IUCN Red List of Threatened Species. Version 2020-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2020).
  • Khew, S.K. and Neo, S.S.H. 1997. Butterfly Biodiversity in Singapore with Particular Reference to the Central Catchment Nature Reserve. Proceedings of the Nature Reserves Survey Seminar. Gardens' Bulletin Singapore 49: 273-296.
  • Kiu, K.Y., Loi, C.Y. and Kendrick, R.K. 2007. A decade of butterfly gardening at Kadoorie Farm & Botanic Garden: raising conservation awareness through education. In: Kendrick, R.C. (ed.), Proceedings of the First South East Asian Lepidoptera Conservation Symposium 2006, pp. 117-123. Hong Kong.
  • Melisch, R. and Schutz, P. 2000. Butterflies and beetles in Germany. Traffic Bulletin 18: 91-93.
  • Monastyrskii, A. 2007. Butterflies of Vietnam. Papilionidae. Dolphin Media, London.
  • New, T.R. and Collins, N.M. 1991. Swallowtail butterflies: an action plan for their conservation. International Union for Conservation of Nature and Natural Resources/Species Survival Commission Lepidoptera Specialist Group, Gland, Switzerland.
  • Nijman, V. 2010. An overview of international wildlife trade from Southeast Asia. Biodiversity and Conservation 19(1101-1114).
  • Noerdjito, W.A. and Amir, M. 1992. Kekayaan kupu-kupu di cagar alam Bantimurung Sulawesi selatan dan sekitarnya. Pros.Seminar Hasil Litbang: 330-339.
  • NRDB. 1995. National Red Data Book of Fauna of Nepal. Department of National Parks and Wildlife Conservation, Kathmandu, Nepal.
  • Parsons, M.J. 1992. The butterfly farming and trading industry in the Indo-Australian region and its role in tropical forest conservation. Tropical Lepidoptera 3(Suppl. 1): 1-31.
  • Pontororing, H.H., Warouw, J., Maramis, R.T.D. and Mamahit, J.M.E. 2016. Conservation of Troides helena Linnaeus (Lepidoptera: Papilionidae) in Forest Park of Mount Tumpa, Manado, North Sulawesi. International Journal of Research in Engineering and Science 4(9): 31-35.
  • Putri, I.A.S.L.P. 2016. Handicraft of butterflies and moths (Insecta: Lepidoptera) in Bantimurung Nature Recreation Park and its implications on conservation. Biodiversitas 17(2): 823-831.
  • Pyle, R.M. and Hughes, S.A. 1978. Conservation and Utilization of the Insect Resources of Papua New Guinea. Wildlife Branch, Department of Natural Resources, Port Moresby.
  • Small, R.D.S. 2007. Becoming unsustainable? Recent trends in the formal sector of insect trading in Papua New Guinea. Oryx 41(3): 386-389.
  • UNEP-WCMC. 2012. Review of butterflies from Asia and Oceania subject to long-standing positive opinions. Prepared for the European Commission Directorate General E - Environment ENV.E.2. ? Development and Environment. UNEP-WCMC, Cambridge.
  • Wambi, D. 1996. Birds, bugs and butterflies. New Guinea Insight 6: 5-9.
  • Wang, E., Leung, P.C., Sze, P. and Wong, A. 2003. Butterflies of Hong Kong. Hong Kong Biodiversity ? Agriculture Fisheries and Conservation Department 4: 2-5.

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